CIRCUIT DESCRIPTION: The TCM uses input from the turbine speed and the output speed sensors to determine gear ratios. The TCM then compares the known gear ratio to the calculated gear ratio for the current range. DTC P0736 sets when the calculated reverse range ratio (steady state) differs from the known reverse range ratio.
ACTION TAKEN WHEN THE DTC SETS: 1. When DTC P0736 is active, the transmission locks in N (Neutral). 2. DTC P0736 is stored in the TCM history. 3. The CHECK TRANS light illuminates (non-OBD II strategy). 4. The TCM forces Variable Modulated Main off. 5. TCM freezes shift adapts (DNA). 6. TCM inhibits TCC engagement.
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: Inspect the speed sensor wiring and connectors for poor electrical connections. Look for the following conditions: 1. A bent terminal 2. A backed-out terminal 3. A damaged terminal 4. Poor terminal tension 5. A chafed wire 6. A broken wire inside the insulation
When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment or the diagnostic tool for a change.
Output or turbine tone wheel damage may cause erratic speed sensor input allowing this DTC to set.
Incorrect ratio DTCs typically indicate mechanical problems with specific clutches, i.e. C3 and C5 for Reverse range.
An incorrect ratio DTC could indicate a hydraulically failed solenoid. Check the DTC information for the specific solenoid.
You may have to drive the vehicle to experience the fault.
Clutch test mode can be used to detect turbine pull-down. If turbine speed is detected, clutch damage may be indicated.
CIRCUIT DESCRIPTION: The transmission TCC solenoid is a pressure control solenoid used to control the rate of TCC apply and release. The TCM applies and releases the TCC by varying the amount of electrical current through a low side driver. The TCM uses data received from the engine speed sensor and the turbine speed sensor to calculate torque converter slip values. It can detect if the torque converter is stuck off (unlocked) or stuck on (locked) by comparing TCC slip speed to a preset value in the TCM calibration. The DTC P0741 sets when the TCM detects a slip speed exceeding a calibrated rpm for calibrated amount of time, indicating no TCC apply.
ACTION TAKEN WHEN THE DTC SETS: 1. DTC P0741 is stored in the TCM history. 2. The TCM forces Variable Modulated Main off. 3. The CHECK TRANS light illuminates.
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: 1. This DTC sets when converter slip speed indicates TCC is not applied when the TCC solenoid is commanded ON for a period of time that is calibration dependent. This may indicate an internal failure of the TCC or a stuck or sticking TCC valve. 2. Residue or contamination may cause shift valves to stick intermittently. 3. This concern may indicate a torque converter flow valve that is stuck or sticking.
CIRCUIT DESCRIPTION: The transmission TCC solenoid is a pressure control solenoid used to control the rate of TCC apply and release. The TCM applies and releases the TCC by varying the amount of electrical current through a low side driver. The TCM uses data received from the engine speed sensor and the turbine speed sensor to calculate torque converter slip values. It can detect if the torque converter is stuck off (unlocked) or stuck on (locked) by comparing TCC slip speed to a preset value in the TCM calibration. DTC P0742 sets when the TCM detects minimal converter slip speed for a calibrated time when TCC state is commanded off. This DTC is only enabled with GM L96 applications.
ACTION TAKEN WHEN THE DTC SETS: 1. The CHECK TRANS light is illuminated. 2. The TCM forces Variable Modulated Main off. 3. Response is calibration dependent. 4. If response is disabled, no action is performed. 5. If enabled, reverse operation is disabled when active.
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: 1. This DTC sets when converter slip speed indicates TCC is staying applied when it should be released for a period of time that is calibration dependent. This may indicate an internal failure of the TCC or a stuck or sticking TCC valve. 2. This concern may indicate a torque converter flow valve that is stuck or sticking.
CIRCUIT DESCRIPTION: The Pressure Switch Manifold (PSM) is a multiple-switch assembly made up of three Normally Open (N/O) and one Normally Closed (N/C) pressure switches. The Pressure Switch 1 (PS1) monitors the SS1 valve positioning and relays it to the TCM. When PS1 is in the open state, SS1 valve should be in the destroked position. DTC P0751 sets when the SS1 valve is commanded on and PS1 status remains Exhausted/OFF for a period of time that is temperature dependent. The intent of this DTC is to detect a shift valve timeout condition which normally indicates a stuck shift valve in the destroked state, mechanical solenoid failure or an open circuit condition.
ACTION TAKEN WHEN THE DTC SETS: When DTC P0751 is active, the following conditions occur: 1. If the failure occurs while in a forward range a shift to 1st, 3rd, or 5th range is made. 2. While diagnostic response is active, if shift selector is moved to N (Neutral), transmission shifts to neutral; if the shift selector is moved to R (Reverse), transmission shifts to reverse. If the shift selector is moved to D (Drive) or R (Reverse) and transmission is compromised by overspeeding or direction change, transmission shifts to neutral. 3. DTC is stored in TCM history. 4. The CHECK TRANS light illuminates (non-OBD II strategy). 5. The TCM forces Variable Modulated Main off. 6. TCM inhibits TCC engagement. 7. TCM freezes shift adapts (DNA).
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: The following procedures are not documented in any OEM procedures or in any OEM Troubleshooting or Service information and therefore should not be used as a method to diagnose any transmission DTCs, function, or shift quality concern:
1. Back-probing any connections used for transmission features or functions may damage and/or unlock terminals from the back-probed connector creating permanent or intermittent shorts and/or open circuits. If possible, use the J-39700 Breakout Box, the appropriate harness adapters, and appropriate magnetic overlays to troubleshoot the vehicle.
2. Load-testing any transmission-related circuits with any other electrical devices such as vehicle lamps or relays, especially with the TCM connected to the harness. Use J-39700 Breakout Box and appropriate harnesses with PS1 to monitor the circuit performance in question unless otherwise specified in the various Troubleshooting information.
3. Piercing a wire to check for voltages, shorts-to-grounds or other wires anywhere in the circuit but especially at the TCM. This creates a leak path for moisture and damages the wire and insulation.
Inspect the wiring for poor electrical connections at the TCM. Look for the following conditions: 1. A bent terminal. 2. A backed-out terminal. 3. A damaged terminal. 4. Poor terminal tension. 5. A chafed wire. 6. A broken wire inside the insulation.
When P0843 and P0751 are set in combination, the TCM logic re-attempted to command the shift solenoid on. A circuit or pressure switch concern exists. Refer to DTC P0843 for further instruction.
When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. It may be necessary to check for shorting-to-ground at individual wires within a harness to isolate an intermittent condition (refer to WIRE CHECK and Intermittent Fault information).
You may have to drive the vehicle in order to experience a fault. Use the data obtained from failure records to determine transmission range and/or certain vehicle operating variables such as temperature, run time etc. This data can be useful in reproducing failures mode where DTC was set.
Multiple inactive pressure switch DTCs may be due to a plugged control main filter.
Whenever performing any internal valve body repair be sure that your work area is free of airborne dust and dirt that might contaminate the valve body assembly. Always store any reusable oil in a clean, covered container. It is recommended that a funnel which incorporates a screen filter be used to refill or strain the oil through an appropriate screen.
Use of a shallow sump filter in a deep sump pan can also set this DTC. Inspect for correct filter size.
CIRCUIT DESCRIPTION: The Pressure Switch Manifold (PSM) is a multiple-switch assembly made up of three Normally Open (N/O) and one Normally Closed (N/C) pressure switches. The Pressure Switch 1 (PS1) monitors the SS1 valve positioning and relays it to the TCM. When PS1 is in the open state, SS1 valve should be in the destroked position. DTC P0752 sets when the SS1 valve is commanded on and PS1 status remains Exhausted/OFF for a period of time that is temperature dependent. The intent of this DTC is to detect a shift valve timeout condition which normally indicates a stuck shift valve in the stroked state, mechanical solenoid failure or a circuit short-to-ground.
ACTION TAKEN WHEN THE DTC SETS: When DTC P0752 is active, the following conditions will occur: 1. If the failure occurs while in a forward range a shift to 1st, 3rd, or 5th range is made. 2. While diagnostic response is active, if shift selector is moved to N (Neutral), transmission shifts to neutral; if the shift selector is moved to R (Reverse), transmission shifts to reverse. If the shift selector is moved to D (Drive) or R (Reverse) and transmission is compromised by overspeeding or direction change, transmission shifts to neutral. 3. DTC is stored in TCM history. 4. The CHECK TRANS light illuminates (non-OBD II strategy). 5. The TCM forces Variable Modulated Main off. 6. TCM inhibits TCC engagement. 7. TCM freezes shift adapts (DNA).
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: The following procedures are not documented in any OEM procedures or in any OEM troubleshooting or Service information and therefore should not be used as a method to diagnose any transmission DTCs, function, or shift quality concern:
1. Back-probing any connections used for transmission features or functions may damage and/or unlock terminals from the back-probed connector creating permanent or intermittent shorts and/or open circuits. If possible, use the J-39700 Breakout Box, the appropriate harness adapters, and appropriate magnetic overlays to troubleshoot the vehicle.
2. Load-testing any transmission-related circuits with any other electrical devices such as vehicle lamps or relays, especially with the TCM connected to the harness. Use J-39700 Breakout Box and appropriate harnesses with the diagnostic tool to monitor the circuit performance in question unless otherwise specified in the various Troubleshooting information.
3. Piercing a wire to check for voltages, shorts-to-grounds or other wires anywhere in the circuit but especially at the TCM. This creates a leak path for moisture and damages the wire and insulation.
Inspect the wiring for poor electrical connections at the TCM. Look for the following conditions: 1. A bent terminal. 2. A backed-out terminal. 3. A damaged terminal. 4. Poor terminal tension. 5. A chafed wire. 6. A broken wire inside the insulation.
When P0842 and P0752 are set in combination, the TCM logic re-attempted to command the shift solenoid on. A circuit or pressure switch concern exists. Refer to DTC P0842 for further instruction.
When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. It may be necessary to check for shorting-to-ground at individual wires within a harness to isolate an intermittent condition (refer to WIRE CHECK and Intermittent Fault information).
You may have to drive the vehicle in order to experience a fault. Use the data obtained from failure records to determine transmission range and/or certain vehicle operating variables such as temperature, run time etc. This data can be useful in reproducing failures mode where DTC was set.
Multiple inactive pressure switch DTCs may be due to a plugged control main filter.
Whenever performing any internal valve body repair be sure that your work area is free of airborne dust and dirt that might contaminate the valve body assembly. Always store any reusable oil in a clean, covered container. It is recommended that a funnel which incorporates a screen filter be used to refill or strain the oil through an appropriate screen.
CIRCUIT DESCRIPTION: The Pressure Switch Manifold (PSM) is a multiple-switch assembly made up of three Normally Open (N/O) and one Normally Closed (N/C) pressure switches. The Pressure Switch 2 (PS2) monitors the SS2 valve positioning and relays it to the TCM. When PS2 is in the open state, SS2 valve should be in the destroked position. DTC P0756 sets when the SS2 valve is commanded on and PS2 status remains Exhausted/OFF for a period of time that is temperature dependent. The intent of this DTC is to detect a shift valve timeout condition which normally indicates a stuck shift valve in the stroked state, mechanical solenoid failure or a circuit short-to-ground.
ACTION TAKEN WHEN THE DTC SETS: When DTC P0756 is active, the following conditions occur: 1. If the failure occurs while in a forward range a shift to 1st, 3rd, or 5th range is made. 2. While diagnostic response is active, if shift selector is moved to N (Neutral), transmission shifts to neutral; if the shift selector is moved to R (Reverse), transmission shifts to reverse. If the shift selector is moved to D (Drive) or R (Reverse) and transmission is compromised by overspeeding or direction change, transmission shifts to neutral. 3. DTC is stored in TCM history. 4. The CHECK TRANS light illuminates (non-OBD II strategy). 5. The TCM forces Variable Modulated Main off. 6. TCM inhibits TCC engagement. 7. TCM freezes shift adapts (DNA).
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: The following procedures are not documented in any OEM procedures or in any OEM Troubleshooting or Service information and therefore should not be used as a method to diagnose any transmission DTCs, function, or shift quality concern:
1. Back-probing any connections used for transmission features or functions may damage and/or unlock terminals from the back-probed connector creating permanent or intermittent shorts and/or open circuits. If possible, use the J-39700 Breakout Box, the appropriate harness adapters, and appropriate magnetic overlays to troubleshoot the vehicle.
2. Load-testing any transmission-related circuits with any other electrical devices such as vehicle lamps or relays, especially with the TCM connected to the harness. Use J-39700 Breakout Box and appropriate harnesses with diagnostic tool to monitor the circuit performance in question unless otherwise specified in the various Troubleshooting information.
3. Piercing a wire to check for voltages, shorts-to-grounds or other wires anywhere in the circuit but especially at the TCM. This creates a leak path for moisture and damages the wire and insulation.
Inspect the wiring for poor electrical connections at the TCM. Look for the following conditions: 1. A bent terminal. 2. A backed-out terminal. 3. A damaged terminal. 4. Poor terminal tension. 5. A chafed wire. 6. A broken wire inside the insulation.
When P0848 and P0756 are set in combination, the TCM logic re-attempted to command the shift solenoid on. A circuit or pressure switch concern exists. Refer to DTC P0848 for further instruction.
When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. It may be necessary to check for shorting-to-ground at individual wires within a harness to isolate an intermittent condition (refer to WIRE CHECK and DIAGNOSING INTERMITTENT DTCs information).
You may have to drive the vehicle in order to experience a fault. Use the data obtained from failure records to determine transmission range and/or certain vehicle operating variables such as temperature, run time etc. This data can be useful in reproducing failures mode where DTC was set.
Multiple inactive pressure switch DTCs may be due to a plugged Control main filter.
Whenever performing any internal valve body repair be sure that your work area is free of airborne dust and dirt that might contaminate the valve body assembly. Always store any reusable oil in a clean, covered container. It is recommended that a funnel which incorporates a screen filter be used to refill or strain the oil through an appropriate screen.
CIRCUIT DESCRIPTION: The Pressure Switch Manifold (PSM) is a multiple-switch assembly made up of three Normally Open (N/O) and one Normally Closed (N/C) pressure switches. The Pressure Switch 2 (PS2) monitors the SS2 valve positioning and relays it to the TCM. When PS2 is in the open state, SS2 valve should be in the destroked position. DTC P0757 sets when the SS2 valve is commanded on and PS2 status remains Exhausted/OFF for a period of time that is temperature dependent. The intent of this DTC is to detect a shift valve timeout condition which normally indicates a stuck shift valve in the stroked state, mechanical solenoid failure or a circuit short-to-ground.
ACTION TAKEN WHEN THE DTC SETS: When DTC P0757 is active, the following conditions occur: 1. If the failure occurs while in a forward range a shift to 1st, 3rd, or 5th range is made. 2. While diagnostic response is active, if shift selector is moved to N (Neutral), transmission shifts to neutral; if the shift selector is moved to R (Reverse), transmission shifts to reverse. If the shift selector is moved to D (Drive) or R (Reverse) and transmission is compromised by overspeeding or direction change, transmission shifts to neutral. 3. DTC is stored in TCM history. 4. The CHECK TRANS light illuminates (non-OBD II strategy). 5. The TCM forces Variable Modulated Main off. 6. TCM inhibits TCC engagement. 7. TCM freezes shift adapts (DNA).
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: The following procedures are not documented in any OEM procedures or in any OEM Troubleshooting or Service information and therefore should not be used as a method to diagnose any transmission DTCs, function, or shift quality concern:
1. Back-probing any connections used for transmission features or functions may damage and/or unlock terminals from the back-probed connector creating permanent or intermittent shorts and/or open circuits. If possible, use the J-39700 Breakout Box, the appropriate harness adapters, and appropriate magnetic overlays to troubleshoot the vehicle.
2. Load-testing any transmission-related circuits with any other electrical devices such as vehicle lamps or relays, especially with the TCM connected to the harness. Use J-39700 Breakout Box and appropriate harnesses with diagnostic tool to monitor the circuit performance in question unless otherwise specified in the various Troubleshooting information.
3. Piercing a wire to check for voltages, shorts-to-grounds or other wires anywhere in the circuit but especially at the TCM. This creates a leak path for moisture and damages the wire and insulation.
Inspect the wiring for poor electrical connections at the TCM. Look for the following conditions: 1. A bent terminal. 2. A backed-out terminal. 3. A damaged terminal. 4. Poor terminal tension. 5. A chafed wire. 6. A broken wire inside the insulation.
When P0847 and P0757 are set in combination, the TCM logic re-attempted to command the shift solenoid on. A circuit or pressure switch concern exists. Refer to DTC P0847 for further instruction.
When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. It may be necessary to check for shorting-to-ground at individual wires within a harness to isolate an intermittent condition (refer to WIRE CHECK and DIAGNOSING INTERMITTENT DTCs information).
You may have to drive the vehicle in order to experience a fault. Use the data obtained from failure records to determine transmission range and/or certain vehicle operating variables such as temperature, run time etc. This data can be useful in reproducing failures mode where DTC was set.
Multiple inactive pressure switch DTCs may be due to a plugged Control main filter.
Whenever performing any internal valve body repair be sure that your work area is free of airborne dust and dirt that might contaminate the valve body assembly. Always store any reusable oil in a clean, covered container. It is recommended that a funnel which incorporates a screen filter be used to refill or strain the oil through an appropriate screen.
Use of a shallow sump filter in a deep sump pan can also set this DTC. Inspect for correct filter size.
CIRCUIT DESCRIPTION: The Pressure Switch Manifold (PSM) is a multiple-switch assembly made up of three Normally Open (N/O) and one Normally Closed (N/C) pressure switches. The Pressure Switch 3 (PS3) monitors the SS3 valve positioning and relays it to the TCM. When PS3 is in the open state, SS3 valve should be in the destroked position. DTC P0761 sets when the SS3 valve is commanded on and PS3 status remains Exhausted/OFF for a period of time that is temperature dependent. The intent of this DTC is to detect a shift valve timeout condition which normally indicates a stuck shift valve in the stroked state, mechanical solenoid failure or a circuit short-to-ground.
ACTION TAKEN WHEN THE DTC SETS: When DTC P0761 is active, the following conditions occur: 1. If the failure occurs while in a forward range a shift to 1st, 3rd, or 5th range is made. 2. While diagnostic response is active, if shift selector is moved to N (Neutral), transmission shifts to neutral; if the shift selector is moved to R (Reverse), transmission shifts to reverse. If the shift selector is moved to D (Drive) or R (Reverse) and transmission is compromised by overspeeding or direction change, transmission shifts to neutral. 3. DTC is stored in TCM history. 4. The CHECK TRANS light illuminates (non-OBD II strategy). 5. The TCM forces Variable Modulated Main off. 6. TCM inhibits TCC engagement. 7. TCM freezes shift adapts (DNA).
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: The following procedures are not documented in any OEM procedures or in any OEM Troubleshooting or Service information and therefore should not be used as a method to diagnose any transmission DTCs, function, or shift quality concern:
1. Back-probing any connections used for transmission features or functions may damage and/or unlock terminals from the back-probed connector creating permanent or intermittent shorts and/or open circuits. If possible, use the J-39700 Breakout Box, the appropriate harness adapters, and appropriate magnetic overlays to troubleshoot the vehicle.
2. Load-testing any transmission-related circuits with any other electrical devices such as vehicle lamps or relays, especially with the TCM connected to the harness. Use J-39700 Breakout Box and appropriate harnesses with diagnostic tool to monitor the circuit performance in question unless otherwise specified in the various Troubleshooting information.
3. Piercing a wire to check for voltages, shorts-to-grounds or other wires anywhere in the circuit but especially at the TCM. This creates a leak path for moisture and damages the wire and insulation.
Inspect the wiring for poor electrical connections at the TCM. Look for the following conditions: 1. A bent terminal. 2. A backed-out terminal. 3. A damaged terminal. 4. Poor terminal tension. 5. A chafed wire. 6. A broken wire inside the insulation.
When P0873 and P0761 are set in combination, the TCM logic re-attempted to command the shift solenoid on. A circuit or pressure switch concern exists. Refer to DTC P0873 for further instruction.
When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. It may be necessary to check for shorting-to-ground at individual wires within a harness to isolate an intermittent condition (refer to WIRE CHECK and DIAGNOSING INTERMITTENT DTCs information).
You may have to drive the vehicle in order to experience a fault. Use the data obtained from failure records to determine transmission range and/or certain vehicle operating variables such as temperature, run time etc. This data can be useful in reproducing failures mode where DTC was set.
Multiple inactive pressure switch DTCs may be due to a plugged Control main filter.
Whenever performing any internal valve body repair be sure that your work area is free of airborne dust and dirt that might contaminate the valve body assembly. Always store any reusable oil in a clean, covered container. It is recommended that a funnel which incorporates a screen filter be used to refill or strain the oil through an appropriate screen.
CIRCUIT DESCRIPTION: The Pressure Switch Manifold (PSM) is a multiple-switch assembly made up of three Normally Open (N/O) and one Normally Closed (N/C) pressure switches. The Pressure Switch 3 (PS3) monitors the SS3 valve positioning and relays it to the TCM. When PS3 is in the open state, SV3 valve should be in the destroked position. DTC P0762 sets when the SS3 valve is commanded off and PS3 status remains Pressurized/ON for a period of time that is temperature dependent. The intent of this DTC is to detect a shift valve timeout condition which normally indicates a stuck shift valve in the stroked state, mechanical solenoid failure or a circuit short-to-ground.
ACTION TAKEN WHEN THE DTC SETS: When DTC P0762 is active, the following conditions occur: 1. If the failure occurs while in a forward range a shift to 1st, 3rd, or 5th range is made. 2. While diagnostic response is active, if shift selector is moved to N (Neutral), transmission shifts to neutral; if the shift selector is moved to R (Reverse), transmission shifts to reverse. If the shift selector is moved to D (Drive) or R (Reverse) and transmission is compromised by overspeeding or direction change, transmission shifts to neutral. 3. DTC is stored in TCM history. 4. The CHECK TRANS light illuminates (non-OBD II strategy). 5. The TCM forces Variable Modulated Main off. 6. TCM inhibits TCC engagement. 7. TCM freezes shift adapts (DNA).
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: The following procedures are not documented in any OEM procedures or in any OEM Troubleshooting or Service information and therefore should not be used as a method to diagnose any transmission DTCs, function, or shift quality concern:
1. Back-probing any connections used for transmission features or functions may damage and/or unlock terminals from the back-probed connector creating permanent or intermittent shorts and/or open circuits. If possible, use the J-39700 Breakout Box, the appropriate harness adapters, and appropriate magnetic overlays to troubleshoot the vehicle.
2. Load-testing any transmission-related circuits with any other electrical devices such as vehicle lamps or relays, especially with the TCM connected to the harness. Use J-39700 Breakout Box and appropriate harnesses with diagnostic tool to monitor the circuit performance in question unless otherwise specified in the various Troubleshooting information.
3. Piercing a wire to check for voltages, shorts-to-grounds or other wires anywhere in the circuit but especially at the TCM. This creates a leak path for moisture and damages the wire and insulation.
Inspect the wiring for poor electrical connections at the TCM. Look for the following conditions: 1. A bent terminal. 2. A backed-out terminal. 3. A damaged terminal. 4. Poor terminal tension. 5. A chafed wire. 6. A broken wire inside the insulation.
When P0872 and P0762 are set in combination, the TCM logic re-attempted to command the shift solenoid on. A circuit or pressure switch concern exists. Refer to DTC P0872 for further instruction.
When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. It may be necessary to check for shorting-to-ground at individual wires within a harness to isolate an intermittent condition (refer to WIRE CHECK and DIAGNOSING INTERMITTENT DTCs information).
You may have to drive the vehicle in order to experience a fault. Use the data obtained from failure records to determine transmission range and/or certain vehicle operating variables such as temperature, run time etc. This data can be useful in reproducing failures mode where DTC was set.
Multiple inactive pressure switch DTCs may be due to a plugged Control main filter.
Whenever performing any internal valve body repair be sure that your work area is free of airborne dust and dirt that might contaminate the valve body assembly. Always store any reusable oil in a clean, covered container. It is recommended that a funnel which incorporates a screen filter be used to refill or strain the oil through an appropriate screen.
Use of a shallow sump filter in a deep sump pan can also set this DTC. Inspect for correct filter size.
CIRCUIT DESCRIPTION: Pressure Control Solenoid 2 (PCS2) controls oncoming, off-going, and holding pressure to any one of the five clutches. This solenoid is referred to as a Pressure Proportional to Current (PPC) solenoid since the output hydraulic pressure supplied by this solenoid is proportional to the controlled current command.
The TCM uses information from the turbine and output speed sensors to detect if a clutch is slipping. The clutch being controlled by PCS2 varies depending on the shift that was being completed. DTC P0776 sets when the TCM detects an incorrect oncoming ratio (range-to-range) for an accumulated number of occurrences.
ACTION TAKEN WHEN THE DTC SETS: When DTC P0776 is active, the following conditions occur: 1. If failure occurs while in a forward range, the transmission shifts to the previous range. 2. If failure occurs while in N (Neutral) or R (Reverse), the transmission locks in N (Neutral). 3. If the shift selector is moved to N (Neutral), the transmission shifts to N (Neutral) (some cases may lock in N (Neutral)). 4. If the shift selector is moved to R (Reverse), the transmission shifts to R (Reverse) or N (Neutral). 5. If the shift selector is returned to a forward range and the transmission is compromised by overspeeding or a direction change, the transmission will shift to N (Neutral). 6. DTC is stored in TCM history. 7. The CHECK TRANS light illuminates (non-OBD II strategy). 8. The TCM forces Variable Modulated Main off. 9. TCM inhibits Torque Converter Clutch (TCC) engagement. 10. TCM freezes shift adapts (DNA).
CONDITIONS FOR CLEARING THE DTC: Use the diagnostic tool to clear the DTC from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without the DTC recurring.
DIAGNOSTIC AIDS: This DTC indicates the oncoming clutch being controlled by PCS2 is not applied or applied too slowly. This could indicate a leak or obstruction in a specific clutch apply circuit. Check the diagnostic tool failure record data for previous or current range information when the DTC was set to determine the specific shift when the DTC was set. Refer to the SOLENOID AND CLUTCH information to determine which clutch circuit is suspect.
If the condition is intermittent, connect the diagnostic tool and select the speed sensor indicated by the DTC. If the signal is erratic, investigate and eliminate the following: 1. Intermittent wiring connection 2. Excessive vibration (driveline or engine torsionals) 3. Irregular sensor gap (loose sensor, loose tone wheel, or damaged tone wheel)
NOTE: Clutch failure due to an OEM engine rating exceeding the OEM transmission rating, or the installation of an engine power package or module will not be covered under the OEM transmission warranty.
NOTE: Transmissions equipped with Neutral at Stop could create this code if there is a stuck Neutral at Stop Pressure Control Valve (PCV) or a stuck PCS3 (Neutral at Stop only).
