Allison

DIAGNOSTIC RESPONSE:
DNS, SOL OFF (hydraulic default)

CIRCUIT DESCRIPTION:
Pressure Control Solenoid 3 (PCS3) is a normally closed solenoid used to apply the C5 clutch in Reverse, Neutral, and First and to apply the C3 clutch in Third and Fifth ranges. The Transmission Control Module (TCM) commands the solenoid ON to produce hydraulic pressure in the clutch apply circuit. When PCS3 is commanded OFF, the clutch pressure is released. The TCM sends control current to PCS3 from High Side Driver 2 (HSD2) via wire 171. HSD2 is continuously ON unless the TCM detects a fault condition. The TCM regulates the amount of current to PCS3 by switching PCS3 low side driver ON and OFF. Wire 133 completes the circuit between PCS3 and its low side driver. DTC P0971 indicates that the TCM has detected a failed low condition in the PCS3 electrical circuit. The failed high condition may exist in the high side (wire 171) or low side (wire133).

CONDITIONS FOR RUNNING THE DTC:
TCM initialized normally and engine speed above 200 rpm.

CONDITIONS FOR SETTING THE DTC:
This DTC sets when the TCM detects PCS3 low side driver has been detected in a failed high state.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0971 is active.
1. If failure occurs while in a forward range, then shift to another forward range. If failure occurs while in Neutral (N), the transmission remains in Neutral (N). If failure occurs while in Reverse, the transmission remains in Reverse or shift to Neutral (N). Once range is attained, transmission will be locked in range. There is no response to shift selector requests.
2. DTC is stored in the TCM history.
3. The TCM inhibits Torque Converter Clutch (TCC) engagement.
4. The CHECK TRANS light illuminates.
5. The 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 failure.

DIAGNOSTIC AIDS:
DTC P0971 can be caused by:
1. PCS3 issues such as:
– W133 shorted to another wire or ground in chassis harness.
– W133 (terminal 9 of 20-way) shorted to another wire or ground in internal transmission harness.
– PCS3 defective.
2. Broken or defective connector assemblies allowing pushed back pins to short together.
3. Unlocked connectors, missing seal plugs allowing moisture in connectors.
4. Defective TCM.

Review applicable information in Control System and Transmission Specifications to find additional circuit specifications, system and connector diagrams, and troubleshooting tips.

DIAGNOSTIC RESPONSE:
DNS, SOL OFF (hydraulic default)

CIRCUIT DESCRIPTION:
Shift Solenoid 1 (SS1) is normally closed solenoid used to properly position C1 and C2 logic latch valves in forward ranges. The Transmission Control Module (TCM) commands the solenoid ON to supply control main pressure to the C1 and C2 logic latch valves. When SS1 is commanded OFF, control main pressure is released from the C1 and C2 latch valves.

The TCM sends control current to SS1 from High Side Driver 2 (HSD2) via wire 171. HSD2 is continuously ON unless the TCM detects a fault condition. The TCM energizes SS1 by switching the solenoid’s low side driver ON. Wire 151 completes the circuit between SS1 and its low side driver. DTC P0973 indicates that the TCM has detected a failed low condition in the low side of the SS1 electrical circuit.

CONDITIONS FOR RUNNING THE DTC:
TCM initialized normally and engine speed above 200 rpm.

CONDITIONS FOR SETTING THE DTC:
This DTC sets when the TCM detects SS1 low side driver has been detected in a failed low state.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0973 is active.
1. If failure occurs while in a forward range, then shift to another forward range. If failure occurs while in Neutral (N), the transmission remains in Neutral (N). If failure occurs while in Reverse (R), the transmission remains in Reverse (R) or shifts to Neutral (N). Once range is attained, transmission will be locked in range. There is no response to shift selector requests.
2. DTC is stored in the TCM history.
3. The TCM inhibits Torque Converter Clutch (TCC) engagement.
4. The CHECK TRANS light illuminates.
5. The 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 failure.

DIAGNOSTIC AIDS:
DTC P0973 can be caused by:
1. SS 1 issues such as:
– W151 high resistance, open, or shorted to another wire in chassis harness or chassis ground.
– W151 (terminal 10 of 20-way) high resistance, open, or shorted to another wire or to the control
valve module in the internal transmission harness.
– SS1 defective.
2. Broken or defective connector assemblies allowing pushed back pins to short together.
3. Unlocked connectors, missing seal plugs allowing moisture in connectors.
4. Unlocked connectors, expanded terminals, poor pin crimps or unlocked pins causing high resistance
or open circuit.
5. Defective TCM.

Review applicable information in Control System and Transmission Specifications to find additional circuit specifications, system and connector diagrams, and troubleshooting tips.

DIAGNOSTIC RESPONSE:
DNS, SOL OFF (hydraulic default)

CIRCUIT DESCRIPTION:
Shift Solenoid 1 (SS1) is normally closed solenoid used to properly position C1 and C2 logic latch valves in forward ranges. The Transmission Control Module (TCM) commands the solenoid ON to supply control main pressure to the C1 and C2 logic latch valves. When SS1 is commanded OFF, control main pressure is released from the C1 and C2 latch valves.

The TCM sends control current to SS1 from High Side Driver 2 (HSD2) via wire 171. HSD2 is continuously ON unless the TCM detects a fault condition. The TCM energizes SS1 by switching the solenoid’s low side driver ON. Wire 151 completes the circuit between SS1 and its low side driver. DTC P0973 indicates that the TCM has detected a short-to-battery condition in the low side of the SS1 electrical circuit.

CONDITIONS FOR RUNNING THE DTC:
TCM initialized normally and engine speed above 200 rpm.

CONDITIONS FOR SETTING THE DTC:
This DTC sets when the TCM detects SS1 low side driver has been detected in a failed high state.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0974 is active.
1. If failure occurs while in a forward range, then shift to another forward range. If failure occurs while in Neutral (N), the transmission remains in Neutral (N). If failure occurs while in Reverse (R), the transmission remains in Reverse (R) or shifts to Neutral (N). Once range is attained, transmission will be locked in range. There is no response to shift selector requests.
2. DTC is stored in the TCM history.
3. The TCM inhibits Torque Converter Clutch (TCC) engagement.
4. The CHECK TRANS light illuminates.
5. The 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 failure.

DIAGNOSTIC AIDS:
DTC P097 4 can be caused by:
1. SS 1 issues such as:
– W151 shorted to another wire in chassis harness.
– W151 (terminal 10 of 20-way) shorted to another wire in internal transmission harness.
– SS1 defective.
2. Broken or defective connector assemblies allowing pushed back pins to short together.
3. Unlocked connectors, missing seal plugs allowing moisture in connectors.
4. Defective TCM.

Review applicable information in Control System and Transmission Specifications to find additional circuit specifications, system and connector diagrams, and troubleshooting tips.

DIAGNOSTIC RESPONSE:
7-speed: Allow 2 through 6, N, R

CIRCUIT DESCRIPTION:
The Shift Solenoid 2 (SS2) may either be assigned to retarder models with an air solenoid or to the SS2 required in 7-speed models. For retarder models with an accumulator, the Transmission Control Module (TCM) commands SS2 ON to enable the normally closed air solenoid which allows air pressure to stroke the accumulator piston to pre-fill the retarder cavity during retarder operation. For 7-speed models, the TCM commands the SS2 solenoid ON to send main pressure to both the C2 latch valve and the C6 interlock valve. The TCM sends control current to the solenoid from the High Side Driver 3 (HSD3) through wire 131. HSD3 is continuously ON unless the TCM detects a fault condition. Wire 119 completes the circuit between the solenoid and the TCM low side driver for SS2. The TCM energizes the solenoid by switching the solenoid’s low side driver ON. DTC P0975 indicates that the TCM has detected an open condition in the SS2 solenoid electrical circuit. The open condition may exist in the high side (wire 131) or low side (wire 119).

CONDITIONS FOR RUNNING THE DTC:
TCM initialized normally and engine speed above 200 rpm.

CONDITIONS FOR SETTING THE DTC:
This DTC sets when the TCM detects SS2 low side driver has been detected in a failed open state.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0975 is active:
1. For 7-speed models, limit ranges to Reverse (R) and ranges 2-6 operation.
2. TCM commands retarder OFF.
3. The TCM inhibits TCC engagement.
4. DTC is stored in the TCM history.
5. The CHECK TRANS light illuminates.
6. The TCM freezes shift adapts (DNA).

CONDITIONS FOR CLEARING THE DTC:
Use the diagnostic tool to clear the DTC history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without failure.

DIAGNOSTIC AIDS:
DTC P0975 can be caused by:
1. SS2 (7-speed only) issues such as:
– W119 high resistance or open circuit in chassis harness.
– W119 (terminal 17 of 20-way) high resistance or open circuit in internal transmission harness.
2. Air solenoid (SS2) issues such as:
– W119 high resistance or open circuit in chassis harness.
3. Defective air solenoid (SS2).
4. Unlocked connectors, expanded terminals, poor pin crimps or unlocked pins causing high resistance or open circuit.
5. Defective TCM.

Review applicable information in Control System and Transmission Specifications to find additional circuit specifications, system and connector diagrams, and troubleshooting tips.

DIAGNOSTIC RESPONSE:
7-speed: Allow 2 through 6, N, R. inhibit TCC operation.

CIRCUIT DESCRIPTION:
The Shift Solenoid 2 (SS2) may either be assigned to retarder models with an air solenoid or to the SS2 required in 7-speed models. For retarder models with an accumulator, the Transmission Control Module (TCM) commands SS2 ON to enable the normally closed air solenoid which allows air pressure to stroke the accumulator piston to pre-fill the retarder cavity during retarder operation. For 7-speed models, the TCM commands the SS2 solenoid ON to send main pressure to both the C2 latch valve and the C6 interlock valve. The TCM sends control current to the solenoid from the High Side Driver 3 (HSD3) through wire 131. HSD3 is continuously ON unless the TCM detects a fault condition. Wire 119 completes the circuit between the solenoid and the TCM low side driver for SS2. The TCM energizes the solenoid by switching the solenoid’s low side driver ON. DTC P0976 indicates that the TCM has detected a failed low condition in the SS2 solenoid electrical circuit. The failed low condition may exist in the high side (wire 131) or low side (wire 119).

CONDITIONS FOR RUNNING THE DTC:
TCM initialized normally and engine speed above 200 rpm.

CONDITIONS FOR SETTING THE DTC:
This DTC sets when the TCM detects SS2 low side driver has been detected in a failed low state.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0976 is active:
1. For 7-speed models, limit ranges to Reverse (R) and ranges 2-6 operation.
2. TCM commands retarder OFF.
3. The TCM inhibits TCC engagement.
4. DTC is stored in the TCM history.
5. The CHECK TRANS light illuminates.
6. The TCM freezes shift adapts (DNA).

CONDITIONS FOR CLEARING THE DTC:
Use the diagnostic tool to clear the DTC history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without failure.

DIAGNOSTIC AIDS:
DTC P0976 can be caused by:
1. SS2 (7-speed only) issues such as:
– W119 shorted to another wire in chassis harness.
– W119 (terminal 17 of 20-way) shorted to another wire in internal transmission harness.
2. Air solenoid (SS2) issues such as:
– W119 shorted to another wire in chassis harness.
3. Defective air solenoid (SS2).
4. Defective SS2 (7-speed only).
5. Broken or defective connector assemblies allowing pushed back pins to short together.
6. Unlocked connectors, missing seal plugs allowing moisture in connectors.
7. Defective TCM.

Review applicable information in Control System and Transmission Specifications to find additional circuit specifications, system and connector diagrams, and troubleshooting tips.

DIAGNOSTIC RESPONSE:
7-speed: Allow 2 through 6, N, R

CIRCUIT DESCRIPTION:
The Shift Solenoid 2 (SS2) may either be assigned to retarder models with an air solenoid or to the SS2 required in 7-speed models. For retarder models with an accumulator, the Transmission Control Module (TCM) commands SS2 ON to enable the normally closed air solenoid which allows air pressure to stroke the accumulator piston to pre-fill the retarder cavity during retarder operation. For 7-speed models, the TCM commands the SS2 solenoid ON to send main pressure to both the C2 latch valve and the C6 interlock valve. The TCM sends control current to the solenoid from the High Side Driver 3 (HSD3) through wire 131. HSD3 is continuously ON unless the TCM detects a fault condition. Wire 119 completes the circuit between the solenoid and the TCM low side driver for SS2. The TCM energizes the solenoid by switching the solenoid’s low side driver ON. DTC P0977 indicates that the TCM has detected a failed high condition in the SS2 solenoid electrical circuit. The failed high condition may exist in the high side (wire 131) or low side (wire 119).

CONDITIONS FOR RUNNING THE DTC:
TCM initialized normally and engine speed above 200 rpm.

CONDITIONS FOR SETTING THE DTC:
This DTC sets when the TCM detects SS2 low side driver has been detected in a failed high state.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0977 is active:
1. For 7-speed models, limit ranges to Reverse (R) and ranges 2-6 operation.
2. TCM commands retarder OFF.
3. The TCM inhibits TCC engagement.
4. DTC is stored in the TCM history.
5. The CHECK TRANS light illuminates.
6. The TCM freezes shift adapts (DNA).

CONDITIONS FOR CLEARING THE DTC:
Use the diagnostic tool to clear the DTC history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without failure.

DIAGNOSTIC AIDS:
DTC P0977 can be caused by:
1. SS2 (7-speed only) issues such as:
– W119 shorted to another wire in chassis harness.
– W119 (terminal 17 of 20-way) shorted to another wire in internal transmission harness.
2. Air solenoid (SS2) issues such as:
– W119 shorted to another wire in chassis harness.
3. Defective air solenoid (SS2).
4. Broken of defective connector assemblies allowing pushed back pins to short together.
5. Unlocked connectors, missing seal plugs allowing moisture in connectors.
6. Defective TCM.

Review applicable information in Control System and Transmission Specifications to find additional circuit specifications, system and connector diagrams, and troubleshooting tips.

DIAGNOSTIC RESPONSE:
None

CIRCUIT DESCRIPTION:
Some transmission retarder applications may use an optional retarder pressure sensor (also called EBS pressure sensor, and/or retarder pressure transducer). The retarder pressure sensor provides an analog voltage input to the TCM proportional to the retarder charge pressure. The retarder pressure sensor signal is monitored by TCM software and is used to calculate the delivered retarder torque. The calculated torque message is broadcast by the TCM over the Controller Area Network (CAN) for use by other vehicle controllers located on the CAN. For example, this feature is used when the vehicle has an Electronic Braking System (EBS). EBSs typically use service brakes, engine brakes, and driveline retarders (like the OEM retarder) for the optimal brake combination to slow or stop a vehicle.

NOTE: Refer to Technical Document (TD) 182 on the OEM Extranet for the description and requirements of an EBS.

NOTE: The retarder pressure sensor interface uses the same three TCM pin locations and wire numbers as those assigned to an analog TPS. Therefore, a retarder pressure sensor cannot be integrated on a vehicle with an analog or PWM TPS source.

NOTE: The retarder pressure sensor can potentially be damaged by continuity testers or Digital Multimeters (DMM) set to check continuity. Check voltages only if troubleshooting retarder pressure sensor performance.

The TCM is connected to the retarder pressure sensor by:
1. a 5V reference voltage (W112),
2. a retarder pressure sensor signal (W144), and
3. an analog ground (W158).

CONDITIONS FOR RUNNING THE DTC:
1. The retarder pressure sensor is enabled by calibration.
2. After TCM initializes normally and engine speed is above 200 rpm for more than 5 seconds, this DTC test will run at 0.10 second intervals.
3. DTC P0989 not active.

CONDITIONS FOR SETTING THE DTC:
DTC P0989 sets when W144 signal voltage is less than 0.125V for more than 5 seconds.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0989 is active, the following conditions occur:
1. The TCM does not illuminate the CHECK TRANS light.
2. DTC is stored in TCM history.
3. The CAN message containing retarder torque data is broadcast as “Not Available” (FE hex or 254 decimal).

CONDITIONS FOR CLEARING THE DTC/CHECK TRANS LIGHT:
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 failure.

DIAGNOSTIC AIDS:
DTC P0989 indicates the TCM has detected a voltage signal from the retarder pressure sensor in the low error zone and may be caused by the following:
1. Open or short to ground in W112 or W144 circuits.

NOTE: Shorts or opens in W112 will typically log other sensor failed low DTCs that are using W112 (5V), such as the Oil Level Sensor (OLS) or Retarder Modulation Request (RMR) Sensor. Shorts or opens in W144 (retarder pressure sensor signal) only causes DTC P0989.

2. Retarder pressure sensor set in calibration for a non-retarder pressure sensor transmission application.
3. Missing, defective, or unplugged retarder pressure sensor.
4. Defective retarder pressure sensor sharing 5V supply.
5. 5V wire open or grounded in transmission internal harness.
6. Broken or defective connector assemblies allowing pushed back pins to short together.
7. Unlocked connectors, missing seal plugs allowing moisture in connectors.
8. TCM issue.

Checking the ‘Autodetected and SEM Information’ Data Grid on the diagnostic tool for the ‘Retarder Pressure Transducer Status’ will display whether the retarder pressure sensor is enabled or not enabled in the calibration. ‘Present’ means enabled, ‘Not Present’ means not enabled.

Review applicable information in Control System and Transmission Specifications to find additional circuit specifications, system and connector diagrams, and troubleshooting tips.

DIAGNOSTIC RESPONSE:
None

CIRCUIT DESCRIPTION:
Some transmission retarder applications may use an optional retarder pressure sensor (also called Electronic Braking System (EBS) pressure sensor, and/or retarder pressure transducer). The retarder pressure sensor provides an analog voltage input to the TCM proportional to the retarder charge pressure. The retarder pressure sensor signal is monitored by TCM software and is used to calculate the delivered retarder torque. The calculated torque message is broadcast by the TCM over the Controller Area Network (CAN) for use by other vehicle controllers located on the CAN. For example, this feature is used when the vehicle has an EBS. Electronic Braking Systems typically use service brakes, engine brakes, and driveline retarders (like the retarder) for an optimal brake combination to slow or stop a vehicle.

NOTE: Refer to Technical Document {TD) 182 on the OEM Extranet for the description and requirements of an EBS.

NOTE: The retarder pressure sensor interface uses the same three TCM pin locations and wire numbers as those assigned to an analog TPS. Therefore, a retarder pressure sensor cannot be integrated on a vehicle with an analog or PWM TPS source.

NOTE: The retarder pressure sensor can be damaged by continuity testers or Digital Multimeters (DMM) set to check continuity. Check voltages only if troubleshooting retarder pressure sensor performance.

The TCM is connected to the retarder pressure sensor by:
1. A 5V reference voltage (W112),
2. A retarder pressure sensor signal (W144), and
3. An analog ground (W158).

CONDITIONS FOR RUNNING THE DTC:
1. The retarder pressure sensor is enabled by calibration.
2. After TCM initializes normally and engine speed is above 200 rpm for more than 5 seconds, this DTC test will run at 0.10 second intervals.
3. DTC P0990 not active.

CONDITIONS FOR SETTING THE DTC:
DTC P0990 sets when signal voltage on W144 is more than 4.5V for longer than 5 seconds.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P0990 is active, the following conditions occur:
1. The TCM does not illuminate the CHECK TRANS light.
2. DTC is stored in TCM history.
3. The CAN message containing retarder torque data is broadcast as “Not Available” (FE hex or 254 decimal).

CONDITIONS FOR CLEARING THE DTC/CHECK TRANS LIGHT:
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 failure.

DIAGNOSTIC AIDS:
DTC P0990 indicates the TCM has detected a voltage signal from the retarder pressure sensor in the high error zone and may be caused by the following:
1. Retarder pressure sensor set in calibration for a non-retarder pressure sensor transmission application.
2. Defective retarder pressure sensor.
3. Defective retarder pressure sensor sharing 5V supply.
4. W144 shorted to battery.

NOTE: Short to battery in W144 (retarder pressure sensor signal) only causes DTC P0990. Short to battery in W112 or open in W158, may cause other sensor DTCs like P070D, and/or C1313.

5. Broken or defective connector assemblies allowing pushed back pins to short together.
6. Unlocked connectors, missing seal plugs allowing moisture in connectors.
7. W158 open circuit.
8. TCM issue.

Checking the ‘Autodetected and SEM Information’ Data Grid on the diagnostic tool for the ‘Retarder Pressure Transducer Status’ will display whether the retarder pressure sensor is enabled or not enabled in the calibration. ‘Present’ means enabled; “Not Present’ means not enabled.

Review applicable information in Control System and Transmission Specifications to find additional circuit specifications, system and connector diagrams, and troubleshooting tips.

DIAGNOSTIC RESPONSE:
Command 2nd and allow shifts 2 through 6, N, R

CIRCUIT DESCRIPTION:
The Transmission Control Module (TCM) uses input from the turbine speed and output speed sensors to determine the current commanded for stead state gear ratio. The TCM then compares the known gear ratio to the calculated gear ratio for the current range.

CONDITIONS FOR RUNNING THE DTC:
1. Hydraulic system is pressurized.
2. No shift in progress.
3. Hydraulic default condition not present.
4. Output speed is above 200 rpm.
5. Engine initialization or shutdown is not in process.

CONDITIONS FOR SETTING THE DTC:
DTC P1739 sets during steady-state condition when the calculated low gear ratio differs from the known low gear ratio for more than 2 seconds.

ACTION TAKEN WHEN THE DTC SETS:
When DTC P1739 is active, the following conditions will occur:
1. For a 3700 model, the transmission locks in first range. For a 4700/4800 model, the transmission locks in second range.
2. While diagnostic response is active, the TCM ignores shift selector inputs.
3. The CHECK TRANS light illuminates.
4. DTC is stored in the TCM history.
5. TCM inhibits TCC engagement.
6. TCM freezes shift adapts (DNA).

CONDITIONS FOR CLEARING THE DTC/CHECK TRANS LIGHT:
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:
NOTE: This DTC requires Clutch Test using the diagnostic tool to detect clutch slip during a partial stall and also to pressurize clutches for measurement without needing to drive the vehicle. Note that main pressure and clutch pressures are reduced when the Main Mod Solenoid is energized. Low commanded Main Mod solenoid pressures shown in Data Monitor correlate to reduced main pressure and clutch pressures. Main pressure is reduced by Main Mod in N (Neutral), 1 (First Range), and 2 (Second Range) when engine speed is below 1500 rpm. Higher Main Mod commanded pressures correlate to no reduction in main pressure and clutch pressures. Refer to First Steps and Tips for Troubleshooting and the OEM Technician’s Library for more information about the action requests for Clutch Test, Full Main Pressure Test, and also the procedure for Stall Testing.

DTC P1739 may be caused by:
1. Output speed sensor signal circuit issues.
2. Turbine speed sensor signal circuit issues.
3. Low clutch pressures, main pressure, or control main pressure.
4. Control module issues like stuck/sticky valves, mechanically defective solenoids, broken springs, damaged valve bores, plugged suction filter, damaged gaskets, excessive leaks to exhaust, etc.
5. Transmission issues such as worn and/or damaged seals or seal rings, dislocated snap rings, worn clutch packs, rotating drum damage (affecting turbine speed pickup), debris, excessive hydraulic circuit leaks to exhaust or other hydraulic circuits.

NOTE: Damage to the output speed sensor wheel slot is an indication the driveline does not meet ATI specifications. Correct all driveline issues before putting transmission back in service.

6. Clutch system issues causing a clutch not to release.
7. Issue with TCM.