Chevrolet Trax: DTC P0601, P0603, P0604, OR P062F: Control module memory

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

NOTE: DTCs P0601, P0603, P0604 or P062F could set in other control modules. Verify the DTCs are set in the transmission control module (TCM).

DTC P0601

Control Module Read Only Memory Performance

DTC P0603

Control Module Long Term Memory Reset

DTC P0604

Control Module Random Access Memory Performance

DTC P062F

Control Module Long Term Memory Performance

Circuit/System Description

This is an internal fault detection of the transmission control module (TCM), which is part of the control solenoid valve assembly. This fault is handled inside the TCM and no external circuits are involved.

Conditions for Running the DTC

P0601 or P0604

Runs continuously when TCM is powered up.

P0603

One time at TCM power up.

P062F

One time at TCM power down.

Conditions for Setting the DTC

P0601

TCM has detected a read only memory (ROM) checksum error 5 times.

P0603

TCM has detected a non-volatile memory checksum error at TCM powerup.

P0604

TCM has detected a random access memory (RAM) test error 5 times.

P062F

TCM has detected a non-volatile memory error during power-down.

Action Taken When the DTC Sets

• P0601, P0603, P0604, and P062F are Type A DTCs.
• TCM commands maximum line pressure.
• TCM forces the torque converter clutch (TCC) OFF.
• TCM inhibits TCC engagement.
• TCM freezes transmission adaptive functions.
• TCM commands the high side driver OFF.
• TCM defaults the transmission to 4th gear and reverse.
• Torque management is enabled.
• TCM inhibits neutral idle.
• TCM inhibits Tap Up/Down function.
• TCM inhibits manual shifting of forward gears.

Conditions for Clearing the DTC

P0601, P0603, P0604, and P062F are Type A DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics (Encore, MH8 or MHB) , Automatic Transmission Controls Schematics (Trax, MH8 or MHB)

• Connector End View Reference
• WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX
• Inline Harness Connector End Views (Encore) , Inline Harness Connector End Views (Trax)

Description and Operation

• Electronic Component Description
• Transmission Component and System Description
• Transmission General Description

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

CAUTION: Before programming a control module, the following must be observed, or control module damage may occur:

• The TIS terminal, MDI, and/or scan tool must have the latest software.
• The vehicle battery must be fully charged. The battery voltage should be between 12-14 volts.
• The TIS terminal, MDI, and/or scan tool connections must be secure.
• A battery charger must NOT be connected to the battery when programming a control module.

1. Ignition OFF and all vehicle systems OFF. It may take up to 2 min for all vehicle systems to power down.
2. Ignition ON.
3. Verify that DTC P0601, P0603, P0604, or P062F is not set.

If any of the DTCs are set

Replace the Q8 Control Solenoid Valve Assembly.

If none of the DTCs are set

4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
5. Verify the DTC does not set.

If the DTC sets

Replace the Q8 Control Solenoid Valve Assembly.

If the DTC does not set

6. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Perform the Transmission Adaptive Values Learn following all transmission repairs
• Control Module References for Control Solenoid Valve Assembly replacement, programming and setup

DTC P0634

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0634

Control Module Overtemperature

Circuit/System Description

The transmission control module (TCM) temperature sensor is located inside of the control solenoid valve assembly which has no serviceable components. The TCM monitors the TCM temperature sensor for over temperature protection.

Conditions for Running the DTC

• DTC P0634 is not set.
• TCM temperature is between 0-240ºC (32-464ºF) for 0.25 s.
• Ignition voltage is 9-32 V.
• DTC runs continuously when above conditions are met.

Conditions for Setting the DTC

Condition 1

TCM has detected an internal temperature condition of 144ºC (291ºF) or greater for 5 s.

Condition 2

Ignition voltage is 18 V or greater and the TCM temperature is 50ºC (122ºF) or greater for 2 s.

Action Taken When the DTC Sets

• P0634 is a Type A DTC.
• TCM limits the transmission to 4th gear and reverse.
• TCM inhibits Tap Up/Down function.
• TCM inhibits manual shifting of forward gears.
• TCM enables torque management.
• TCM shuts down.
• TCM commands maximum line pressure.

Conditions for Clearing the DTC

P0634 is a Type A DTC.

Diagnostic Aids

During a road test, the TCM temperature should steadily increase to a normal operating temperature, and then stabilize.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics (Encore, MH8 or MHB) , Automatic Transmission Controls Schematics (Trax, MH8 or MHB)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

• Electronic Component Description
• Transmission Component and System Description
• Transmission General Description

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.
2. Verify the scan tool Engine Coolant Temperature parameter was less than 125ºC (257ºF) when DTC set by reviewing the scan tool Freeze Frame/Failure Records.

If 125ºC (257ºF) or greater

Refer to Engine Overheating .

If less than 125ºC (257ºF)

3. Verify the scan tool TCM Temperature parameter is less than 146ºC (295ºF).

If 146ºC (295ºF) or greater

Replace the Q8 Control Solenoid Valve assembly.

If less than 146ºC (295ºF)

4. Verify the transmission fluid level and condition is correct. Refer to Transmission Fluid Level and Condition Check.

• If the transmission fluid level and condition is not correct

Repair as necessary.

If the transmission fluid level and condition is correct

5. Clear the TCM DTCs with a scan tool.
6. Operate the vehicle until normal engine temperature is reached.
7. Verify the scan tool Transmission Fluid Temperature parameter is less than 140ºC (284ºF).

If 140ºC (284ºF) or greater

1. Ignition OFF.
2. Verify the conditions listed below do not exist:

• Obstructions to the airflow to the radiator or transmission
• Radiator damage
• Transmission cooler damage
• Transmission cooler pipe kinked or damaged

If a condition exists, repair or replace as necessary.

If none of the conditions exist, refer to Transmission Fluid Cooler Flushing and Flow Test .

If less than 140ºC (284ºF)

9. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
10. Verify the DTC does not set.

If the DTC sets

Replace the Q8 Control Solenoid Valve Assembly.

If the DTC does not set

10. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Perform the Transmission Adaptive Values Learn following all transmission repairs
• Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection
• Transmission Fluid Cooler Inlet Pipe Replacement
• Transmission Fluid Cooler Outlet Pipe Replacement
• Control Module References for Control Solenoid Valve Assembly replacement, programming and setup

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