P179B

DTC P179B

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.

DTC Descriptor
DTC P179B
- Range State Command Circuit

Circuit/System Description

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

Conditions for Running the DTC

* The engine is running.
* Ignition voltage is 8-18 volts.

Conditions for Setting the DTC

The control solenoid (w/body and TCM) valve assembly has detected a Range State Command rolling count error for 8 seconds.

Action Taken When the DTC Sets

DTC P179B is a Type A DTC.

Conditions for Clearing the DTC

DTC P179B is a Type A DTC.

Diagnostic Aids

When attempting to set TCM internal DTCs, run the engine for at least 1 minute, and then shut the engine OFF for 30 seconds. Following this procedure will allow for a complete TCM shutdown. Program the TCM with the latest software version and retest the DTC to see if the DTC resets.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information.

Circuit/System Verification

1. Start the engine.
2. Let the engine run for 1 minute, then turn the key OFF for 30 seconds.
3. Retest for DTC P179B.

Circuit/System Testing

Program the TCM with the latest software version and retest for DTCs.

If the DTC resets, replace the control solenoid (w/body and TCM) valve assembly.

Component Testing

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

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning)for control solenoid (w/body and TCM) valve assembly for replacement, setup, and programming.