Allison

NOTE: Due to the TCM logic used to detect and set P0708, this DTC can remain active even after an IMS replacement is complete and the ignition has been cycled. It is important to clear all active DTCs from the TCM after servicing the IMS.

CIRCUIT DESCRIPTION:
The Transmission Fluid Temperature (TFT) sensor is incorporated into the Pressure Switch Manifold (PSM), which is located in the transmission oil pan. The TFT sensor is a thermistor that changes its resistance value based on the temperature of the transmission fluid. The Transmission Control Module (TCM) measures the voltage drop across the TFT sensor. As the TFT sensor resistance changes the voltage drop recorded across the thermistor will increase or decrease proportionately. The TCM uses this information to determine sump temperature.

ACTION TAKEN WHEN THE DTC SETS:
1. The TCM does not illuminate the CHECK TRANS light.
2. The MIL illuminates on the seconds occurrence.
3. The TCM uses calibration default for temperature values.
4. DTC P0711 is stored in the TCM history.

CONDITIONS FOR CLEARING THE DTC:
The diagnostic tool may be used 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. The TCM cancels the DTC default actions when the fault no longer exists, and the ignition has been cycled.

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.

If DTC P0711 does not return when cleared, but was once present, an intermittent condition has occurred on the circuit shown in the thumbnail drawing. Due to the nature of intermittent conditions, it may be necessary to eliminate all of the components associated with the transmission before returning the vehicle to the vehicle manufacturer for harness replacement.

The following components should be tested as indicated before suspecting an OEM vehicle harness:
1. TCM-Substitute a known good TCM and drive vehicle, if concern is eliminated, reinstall old TCM to confirm complaint returns.

2. Internal Harness and PSM-Remove the transmission oil pan, remove internal harness and PSM assembly. Using a DVOM, check for open or shorting conditions and check the thermistor for the proper resistance value.

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 diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.

You may have to drive the vehicle in order to experience a fault.

Using the diagnostic tool monitor TFT. The TFT should rise steadily during warm-up cycles and then stabilize.

DTC P0218 may set after DTC P0711 has set. Follow the diagnostic information for DTC P0711 before proceeding to the diagnostic for DTC P0218.

CIRCUIT DESCRIPTION:
The Transmission Fluid Temperature (TFT) sensor is incorporated into the Pressure Switch Manifold (PSM), which is located in the transmission oil pan. The TFT sensor is a thermistor that changes its resistance value based on the temperature of the transmission fluid. The Transmission Control Module (TCM) measures the voltage drop across the TFT sensor. As the TFT sensor resistance changes the voltage drop recorded across the thermistor will increase or decrease proportionately. The TCM uses this information to determine sump temperature. DTC P0712 sets when the TFT sensor indicates a resistance of less than a calibrated value for a calibrated time.

ACTION TAKEN WHEN THE DTC SETS:
1. The CHECK TRANS light is not illuminated (non-OBD II strategy).
2. The TCM forces Variable Modulated Main off.
3. The TCM uses calibration default for temperature values.
4. DTC P0712 is stored in the TCM history.

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. The TCM cancels the DTC default actions when the fault no longer exists, and the ignition has been cycled.

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.

If DTC P0712 does not return when cleared, but was once present, an intermittent condition has occurred on the circuit shown in the thumbnail drawing. Due to the nature of intermittent conditions, it may be necessary to eliminate all of the components associated with the transmission before returning the vehicle to the vehicle manufacturer for harness replacement.

The following components should be tested as indicated before suspecting an OEM vehicle harness:
1. TCM – Substitute a known good TCM and drive vehicle, if concern is eliminated, reinstall old TCM to confirm complaint returns.
2. Internal Harness and PSM- Remove the transmission oil pan, remove internal harness and PSM assembly. Using a Digital Volt/Ohmmeter (DVOM), check for open or shorting conditions and check the thermistor for the proper resistance value.

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 diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.

You may have to drive the vehicle in order to experience a fault.

DTC P0218 may set after DTC P0712 has set. Follow the diagnostic information for DTC P0712 before proceeding to the diagnostic table for DTC P0218.

A short-to-ground on wire 154 may allow a DTC P0712 to set. A default value of 160°C (320°F) TFT on the diagnostic tool may indicate this has occurred.

CIRCUIT DESCRIPTION:
The Transmission Fluid Temperature (TFT) sensor is incorporated into the Pressure Switch Manifold (PSM), which is located in the transmission oil pan. The TFT sensor is a thermistor that changes its resistance value based on the temperature of the transmission fluid. The Transmission Control Module (TCM) measures the voltage drop across the TFT sensor. As the TFT sensor resistance changes the voltage drop recorded across the thermistor will increase or decrease proportionately. The TCM uses this information to determine sump temperature. DTC P0713 sets when the TFT sensor indicates a resistance of higher than a calibrated value for a calibrated time.

ACTION TAKEN WHEN THE DTC SETS:
1. The CHECK TRANS light is not illuminated (non-OBD II strategy).
2. The TCM forces Variable Modulated Mod off.
3. The TCM uses calibration default for temperature values.
4. DTC P0713 is stored in the TCM history.

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. The TCM cancels the DTC default actions when the fault no longer exists, and the ignition has been cycled.

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.

If DTC P0713 does not return when cleared, but was once present, an intermittent condition has occurred on the circuit shown in the thumbnail drawing. Due to the nature of intermittent conditions, it may be necessary to eliminate all of the components associated with the transmission before returning the vehicle to the vehicle manufacturer for harness replacement.

The following components should be tested as indicated before suspecting an OEM vehicle harness:
1. TCM – Substitute a known good TCM and drive vehicle, if concern is eliminated, reinstall old TCM to confirm complaint returns.
2. Internal Harness and PSM – Remove the transmission oil pan, remove internal harness and PSM assembly. Using a Digital Volt/Ohmmeter (DVOM), check for open or shorting conditions and check the thermistor for the proper resistance value.

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 diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.

You may have to drive the vehicle in order to experience a fault.

DTC P0218 may set after DTC P0713 has set. Follow the diagnostic information for DTC P0713 before proceeding to the diagnostic test for DTC P0218.

CIRCUIT DESCRIPTION:
The speed sensors are variable reluctance devices which convert mechanical motion to an AC voltage. Each sensor consists of a wire coil wrapped around a pole piece that is adjacent to a permanent magnet. These elements are contained in a housing which is mounted adjacent to a rotating ferrous member. Two signal wires extend from one end of the housing and an exposed end of the pole piece is located at the opposite end of the housing. The permanent magnet produces lines of flux around the pole piece. As a ferrous object (a rib on the rotating clutch drum) approaches and passes through the gap at the end of the pole piece, an AC voltage pulse is induced in the wire coil. The TCM calculates the frequency of these AC pulses and converts it to a speed value. The AC voltage generated varies from 150mV at low speed to 15V at high speed. The signal wires from the sensor are formed as twisted pairs to cancel magnetically induced fields. The cable is also shielded to protect from voltage-related fields. Using two-wire differential input at the TCM eliminates noise from other sources.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0715 is active, the following conditions occur:
1. If the DTC sets while shift not in process, remains in current range.
2. If the DTC sets while shift is in process, complete shift and lock in that range.
3. The TCM forces Variable Modulated Main off.
4. DTC is stored in TCM history.
5. The CHECK TRANS light illuminates.
6. The TCM inhibits TCC engagement.
7. The TCM freezes shift adapts.

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:
DTC P0715 may be caused by:
1. W120 and/or W180 shorted to another wire in chassis harness or to ground.
2. W120 and/or W180 high resistance or open circuit.
3. Broken or defective connector assemblies allowing pushed back pins to short together.
4. Unlocked connectors, missing seal plugs allowing moisture in connectors.
5. Fatigued wires at speed sensor connectors (broken strands).
6. Incorrect pin crimps or expanded terminals.
7. Defective turbine shaft speed sensor.
8. Defective TCM.
9. Damaged rotating clutch drum.
10. Wire pair not twisted or not sufficiently twisted.

NOTE: Confirm that the speed sensor wiring consists of twisted pairs at the rate of 12 to 16 twists per 300 mm. These twists must extend the entire length of the wiring harness to within at least 50 mm of the speed sensor connector.

NOTE: OEM Transmission warranty, or the extended coverage for parts and labor, does not cover transmission or vehicle damage caused by drivelines that do not meet the OEM specifications.

CIRCUIT DESCRIPTION:
The speed sensors are variable reluctance devices which convert mechanical motion to an AC voltage. Each sensor consists of a wire coil wrapped around a pole piece that is adjacent to a permanent magnet. These elements are contained in a housing which is mounted adjacent to a rotating ferrous member. Two signal wires extend from one end of the housing and an exposed end of the pole piece is located at the opposite end of the housing. The permanent magnet produces lines of flux around the pole piece. As a ferrous object (such as a gear tooth) approaches and passes through the gap at the end of the pole piece, an AC voltage pulse is induced in the wire coil. The TCM calculates the frequency of these AC pulses and converts it to a speed value. The signal wires from the sensor are formed as twisted pairs to cancel magnetically induced fields. The cable is also shielded to protect from voltage-related fields. Noise from other sources is eliminated by using two-wire differential inputs at the TCM. DTC P0716 can be set when one of the following occur, unrealistic large change in turbine speed, or noisy turbine speed signal.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0716 is active, the following conditions occur:
1. If failure occurs while in a forward range and a shift has been completed, the transmission will remain in the current range.
2. If failure occurs while in a forward range and a shift is in progress, the transmission will return to the previous range, except in post-shift state; then the transmission will continue to the commanded range.

DTC P0716 is stored in the TCM history.

The CHECK TRANS light illuminates (non-OBD II strategy).

The TCM inhibits TCC engagement.

The TCM forces Variable Modulated Main off.

CONDITIONS FOR CLEARING THE DTC:
The diagnostic tool may be used 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 diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.

You may have to drive the vehicle in order to experience a fault.

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 torsional)
3. Irregular sensor gap (loose sensor, loose, or damaged tone wheel)

Install a known good speed sensor and see if normal function is restored to rule out an internal short or open in the sensor removed.

Check that the speed sensor wiring consists of twisted pairs at the rate of 12 to 16 twists per 300 mm (12 inches). These twists must extend the entire length of the wiring harness to within at least 50 mm (2 inches) of the speed sensor connector.

Inspect the turbine speed tone wheel/Power Takeoff (PTO) gear for possible damage.

Install a known good TCM, if available. If the DTC does not return, reinstall the old TCM to verify the repair.

CIRCUIT DESCRIPTION:
When Neutral at Stop is active, the TCM automatically commands transmission operation at a reduced load state similar to Neutral (N). The purpose of the function is to reduce the load on the engine when the vehicle is stopped which improves fuel economy and also reduces heat load of the transmission in high start/stop duty cycles. To activate Neutral at Stop, the vehicle must be in first range, at a stop, service brakes applied, accelerator pedal approximately at 0%, and the TCM GPI terminal for Neutral at Stop must see V+, V Ign, or V Bat. Neutral at Stop deactivates when the service brake is released. Supplemental controls such as a door switch or a Neutral Stop enable dash switch may be wired in series with the service brake pressure switch or, alternately, a vehicle Programmable Logic Controller (PLC) output may switch the Neutral at Stop signal as a result of a service brake pressure switch input to the PLC. The signal used to activate Neutral at Stop is W143, depending upon which Input/Output (I/O) package was selected in the TCM calibration. Neutral at Stop typically uses a switch-to-battery input (analog). Refer to the OEM Technician Library for Neutral at Stop wiring information. The test monitors whether the Neutral at Stop input status is in a stuck “ON” or “OFF” state.

Neutral at Stop:
GPI#: 3
GPI Type: +
TCM Pin Number: 43
Wire Number: 143
Wire Color: Blue
Termination Point(s): Service Brake Pressure Switch to V+ or PLC Output

ACTION TAKEN WHEN THE DTC SETS:
When DTC P071A is active, the following conditions occur:
1. The DTC is stored in the TCM history.
2. The TCM does not illuminate the CHECK TRANS light.
3. TCM inhibits Neutral at Stop operation.

CONDITIONS FOR CLEARING THE DTC/CHECK TRANS LIGHT:
The diagnostic tool may be used 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 may be caused by:
1. Short to power or short to another wire for the GPI circuit controlling Neutral at Stop feature, i.e., W143.
2. For service brake integrations, defective switch or incorrect wiring, e.g., pressure switches are closed when they should be open. If Neutral at Stop enable switch or door switch integrated in series, all switches would need to be stuck closed or wired on wrong side of switches, e.g., normally closed side vs normally open side.
3. For PLC Neutral at Stop integrations, a miswired, misprogrammed, or defective circuit from PLC controlling the TCM GPI signal for Neutral at Stop that is maintaining circuit above 3.4 volts with service brakes released.
4. Neutral at Stop enabled in TCM programming in error.
5. TCM ground is at different voltage potential than the ground of the OEM voltage source responsible for switching GPI circuit controlling Neutral at Stop, e.g. PLC, vehicle ignition, body controller, etc.
6. Defective TCM.

NOTE: The OEM transmission warranty, or the extended coverage for parts and labor, does not cover the repair or replacement of OEM or body builder provided components or any external wire harnesses not provided by the OEM.

Before repairing or replacing these components or circuits that caused a transmission issue, always contact the vehicle OEM call center and/or the vehicle OEM or bodybuilder service representative to verify the warranty coverage and proper payment arrangements, arrange an alternate sublet or repair plan (if needed), and get troubleshooting assistance for the repair (such as vehicle schematics, DTC trees, parts assistance, etc).

CIRCUIT DESCRIPTION:
The speed sensors are devices which convert mechanical motion to an electrical signal. This test detects an output speed sensor circuit short to battery, ground, or open.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0720 is active, the following conditions occur:
1. If the DTC sets while shift not in process, remains in current range.
2. If the DTC sets while shift is in progress, complete shift and lock in that range.
3. The TCM forces Variable Modulated Main off.
4. DTC is stored in TCM history.
5. The CHECK TRANS light illuminates.
6. The TCM inhibits TCC engagement.
7. The TCM freezes shift adapts.

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:
DTC P0720 may be caused by:
1. W140 and/or W160 shorted to another wire in chassis harness or to ground.
2. W140 and/or W160 high resistance or open circuit.
3. Broken or defective connector assemblies allowing pushed back pins to short together.
4. Unlocked connectors, missing seal plugs allowing moisture in connectors.
5. Fatigued wires at speed sensor connectors (broken strands).
6. Incorrect pin crimps or expanded terminals.
7. Defective output shaft speed sensor.
8. Defective TCM.
9. Wire pair not twisted or not sufficiently twisted.

NOTE: Confirm that the speed sensor wiring consists of twisted pairs at the rate of 12 to 16 twists per 300 mm. These twists must extend the entire length of the wiring harness to within at least 50mm of the speed sensor connector.

NOTE: OEM Transmission warranty, or the extended coverage for parts and labor, does not cover transmission or vehicle damage caused by drivelines that do not meet the OEM specifications.

NOTE: The OEM transmission warranty, or the extended coverage for parts and labor, does not cover the repair or replacement of OEM or bodybuilder-provided components or any external wire harnesses not provided by the OEM.

Before repairing or replacing these components or circuits that caused a transmission issue, always contact the vehicle OEM call center and/or the vehicle OEM or bodybuilder service representative to verify the warranty coverage and proper payment arrangements, arrange an alternate sublet or repair plan (if needed), and get troubleshooting assistance for the repair (such as vehicle schematics, DTC trees, parts assistance, etc).