Powertrain Management

DTC P150C

Diagnostic Instructions

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

DTC Descriptor
DTC P150C
- Transmission Control Module (TCM) Engine Speed Request Circuit

Diagnostic Fault Information





Circuit/System Description

Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits for each virtual network. The messages are supervised and periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.

Conditions for Running the DTC

* The system voltage is between 9-16 volts.
* The vehicle power mode requires serial data communications.

Conditions for Setting the DTC

A supervised periodic message that includes the transmitter module availability has not been received, or is intermittently missing.

Action Taken When the DTC Sets

DTC P150C is a Type C DTC.

Conditions for Clearing the DTC

DTC P150C is a Type C DTC.

Diagnostic Aids

Use the DTC Descriptor list to determine the module which is not communicating. If there are multiple non-communicating modules in series on high speed GMLAN, choose the one closest to the data link connector (DLC) for this diagnostic.

Reference Information
Schematic Reference

Data Communication Schematics (Electrical Diagrams)
Connector End View Reference

Master Electrical Component List (A - Z Index)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
* GMLAN Wiring Repairs (GMLAN Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)

Circuit/System Testing

1. Using the DTC Descriptor and Diagnostic Aids, determine which module is not communicating.
2. Ignition OFF, disconnect the harness connector at the module that is not communicating.
3. Test for less than 0.5 ohm of resistance between each ground circuit of the module that is not communicating and ground.

• If greater than 0.5 ohm, repair the open/high resistance in the ground circuit.

4. Test for battery voltage between each battery positive voltage circuit of the module that is not communicating and ground.

• If less than battery voltage, repair the short to ground or open/high resistance in the battery positive voltage circuit.

5. Ignition ON, test for battery voltage between each ignition circuit of the module that is not communicating and ground.

• If less than battery voltage, repair the short to ground or open/high resistance in the ignition circuit.

6. Ignition OFF, disconnect the harness connector at the module that reported the no communication DTC.
7. Ignition OFF, test for less than 0.5 ohm of resistance in each serial data circuit between the module that is not communicating and the module that reported the DTC.

• If greater than 0.5 ohm, repair the open/high resistance in the serial data circuit.

8. If all tests normal, replace the module that is not communicating.

Repair Instructions

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

Control Module References (Programming and Relearning) for non-communicating module replacement, setup, and programming