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 P0ADB: Hybrid Battery Positive Contactor Control Circuit Low Voltage

DTC P0ADC: Hybrid Battery Positive Contactor Control Circuit High Voltage

Circuit/System Description

The generator battery disconnect control module monitors the contactor control circuit for a shorted low or high condition.

Conditions for Running the DTC

Ignition On.

Conditions for Setting the DTC

P0ADB

Contactor control feedback is greater than 98 percent.

P0ADC

Contactor control feedback is less than 5 percent.

Action Taken When the DTC Sets

Hybrid system is disabled.

Conditions for Clearing the DTC

    • State is Run, Service or Powerdown.
    • Contactor state = Closed.
    • Contactor status = Open, Service or Disconnect.

Diagnostic Aids

    • Possible wiring harness short to ground.
    • Possible wiring harness short to voltage or open

Reference Information

Schematic Reference

Hybrid Energy Storage Schematics

Connector End View Reference

Hybrid Energy Storage Connector End Views

Electrical Information Reference

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

Scan Tool Reference

Scan Tool Data List

Circuit/System Verification

Caution: To help avoid personal injury, additional precautions must be taken prior to working on the generator control module or the generator starter. After removing the 36V battery cables from the generator battery, remove both engine wiring harness connectors from the generator control module. Wait at least 5 minutes and then remove the generator control module cover. Verify voltage levels at all 36V, 12V, and 3-phase connections, are less than 3 volts using a DMM before proceeding.

Caution: 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. If verify the DTC is set current.
  2. If the DTC is history refer to Diagnostic Aids.
  3. Using the ECM scan tool contactor control special function command the contactor Open and Closed.
  4. If the contactor does not operate and or the DTC resets replace the generator battery disconnect control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for generator battery disconnect control module replacement, setup, and programming