GM Service Manual Online
For 1990-2009 cars only

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

DTC P0A06: Starter/Generator Control Module Coolant Pump Control Circuit High Voltage

DTC P0A07: Starter/Generator Control Module Coolant Pump Control Circuit Low Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Starter/Generator Control module (SGCM) Coolant Pump B+

P0A7C

P0A7C

--

--

Starter/Generator Control module (SGCM) Coolant Pump Control

P0A07

P0A07

P0A06

--

Circuit/System Description

The starter/generator control module (SGCM) monitors the SGCM coolant pump control circuit for an open circuit or a over current condition.

Conditions for Running the DTC

Engine ON.

Conditions for Setting the DTC

P0A06

The SGCM detects a short to voltage in the SGCM coolant pump control circuit for 320 ms or greater.

P0A07

The SGCM detects a short to ground or an open/high resistance in the SGCM coolant pump control circuit for 320 ms or greater.

Action Taken When the DTC Sets

    • Hybrid system disabled.
    • malfunction indicator lamp (MIL) is commanded ON.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • The ignition must be cycled before the DTC can be cleared.

Reference Information

Schematic Reference

Hybrid Cooling Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Starter Generator Control Module Cooling System Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Warning: To help avoid personal injury, be careful when working in the vicinity of the generator battery disconnect control module. Internal components will still be live, 36V potential, even when the cover has been opened or removed.

  1. Ignition OFF, disconnect the harness connector at the SGCM coolant pump.
  2. Ignition ON, test for B+ between the B+ circuit terminal A and ground.
  3. If less than the specified value, test the B+ circuit for a short to ground or an open/high resistance.
  4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal B and ground.
  5. If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the SGCM.
  6. Ignition OFF, verify that a test lamp does not illuminates between B+ and the control circuit terminal B.
  7. If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the SGCM.
  8. Ignition OFF, connect a test lamp between the B+ circuit terminal A and the control circuit terminal B.
  9. Clear the DTC with a scan tool.
  10. Command the SGCM Coolant Pump Relay ON and OFF with a scan tool. The test lamp should turn On and OFF when commanded.
  11. If the test lamp does not turn ON and OFF when commanded, test the control circuit for an open/high resistance. If the circuit tests normal, replace the SGCM.
  12. If all circuits test normal, test or replace the SGCM coolant pump.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Generator Control Module Coolant Pump Replacement
    •  Control Module References for SGCM replacement, setup, and programming