Service Information

Volt

DTC P0601-P0606, P060B, P062F, P16F3, P16F7, P16F8, or P179B - TCM

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 P0601: Control Module Read Only Memory

DTC P0602: Control Module Not Programmed

DTC P0603: Control Module Long Term Memory Reset

DTC P0604: Control Module Random Access Memory

DTC P0606: Control Module Internal Performance

DTC P060B: Control Module Analog to Digital Performance

DTC P062F: Control Module Long Term Memory Performance

DTC P16F3: Control Module Redundant Memory Performance

DTC P16F7: Control Module Pressure Control Solenoid Command Incorrect

DTC P16F8: Control Module Clutch Command Incorrect

DTC P179B: Range State Command Circuit

Circuit/System Description

This is an internal fault detection of the transmission control module (TCM). The transmission control module is part of the control solenoid valve assembly, and is not serviced separately. This fault is handled inside the transmission control module and no external circuits are involved.

Conditions for Running the DTC

The system voltage is 9.5-18V.

Conditions for Setting the DTC

The transmission control module has detected an internal malfunction.

Action Taken When the DTC Sets

•	DTCs P0601, P0602, P0603, P0604, P0606, P060B, P062F, P16F3, P16F7, P16F8, and P179B are Type A DTCs.

•	The TCM shifts to a default mode and turns OFF.

Conditions for Clearing the DTC

DTCs P0601, P0602, P0603, P0604, P0606, P060B, P062F, P16F3, P16F7, P16F8, and P179B are Type A DTCs.

Diagnostic Aids

When attempting to set transmission control module internal DTCs, vehicle ON for at least 1 minute, and then vehicle OFF for 30 seconds. Following this procedure will allow for a complete transmission control module shutdown.

Reference Information

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Verify that DTC P0601, P0602, P0603, P0604, P0606, P060B, P062F, P16F3, P16F7, P16F8 or P179B is not set.

⇒	If the DTC is set, program the Q8 Control Solenoid Valve Assembly. If the DTC resets, replace the Q8 Control Solenoid Valve Assembly.

Component Testing

Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for Control Solenoid Valve Assembly and Transmission Control Module Assembly replacement, programming, and setup.