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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Sierra Denali 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC P0ABB, P0ABC, or P0ABD

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 P0ABB: Hybrid Battery Voltage Sensor Performance

DTC P0ABC: Hybrid Battery Voltage Sensor Circuit Low Voltage

DTC P0ABD: Hybrid Battery Voltage Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Disconnect Lever High Voltage Fuse

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P0A95*, P0ABC*, P1A20**

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--

High Voltage Monitor Positive

P1AE7

P0ABB

--

--

High Voltage Monitor Negative

P1AE7

P0ABB

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--

*DTC P0A95 and P0ABC will only set if the HV contactors are closed when the fuse opens.

**DTC P1A20 will set if the fuse is open when the ignition is turned ON.

Circuit/System Description

The BECM has several methods of monitoring the total voltage values of the hybrid batteries. The BECM monitors the calculated battery voltage and the terminal voltage. The calculated voltage represents the sum of the voltages from the 20 individual battery measurements, and the terminal voltage represents the total DC bus voltage as measured on the output side of the high voltage contactor relays. The BECM compares these two voltage readings and looks for a difference. The BECM also monitors the terminal voltage for both over voltage and under voltage conditions.

Conditions for Running the DTC
    • The ignition is ON.
    • The 12 V battery voltage is 9-18 V.
    • The HV contactors are closed.

Conditions for Setting the DTC

P0ABB

The BECM detects a 50 V difference between the hybrid battery pack calculated voltage and the hybrid battery terminal voltage for 7 seconds.

P0ABC

The BECM detects the terminal voltage is less than 50 V for 3 seconds.

P0ABD

The BECM detects the terminal voltage is greater than 430 V for 3 seconds.

Action Taken When the DTC Sets

The battery vent fan is commanded to high speed.

Conditions for Clearing the DTC

DTCs P0ABB, P0ABC, and P0ABD are type A DTCs.

Reference Information

Schematic Reference

Hybrid Energy Storage Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Drive Motor Battery System Description

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

Special Tools

    • EL-48571 High Voltage Battery Pin Out Box
    • EL-48900 HEV Safety Kit

Circuit/System Verification

Ignition ON, engine OFF, observe the scan tool Hybrid Battery Pack Calculated and Hybrid Battery Terminal parameters. The readings should be between 169 and 408 Volts, and should be within 50 Volts of each other.

Circuit/System Testing

Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

The High Voltage Disabling procedure will perform the following tasks:

   • Identify how to disable high voltage.
   • Identify how to test for the presence of high voltage.
   • Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.
Failure to follow the procedures exactly as written may result in serious injury or death.

P0ABB

  1. Verify that DTC P0ABC is not set.
    2. ⇒If DTC P0ABC is set, diagnose that DTC first.
  2. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling.
  3. Remove the drive motor generator battery case upper cover, front cover and right side cover. Refer to Drive Motor Battery Case Upper Cover, Front Cover, and Right Side Cover Replacement.
  4. Install the high voltage manual disconnect lever.
  5. Ignition OFF, Using a DMM, measure and record the pack voltage by measuring between terminals HV+ at the HV positive contactor relay and HV- at the HV negative contactor relay.
  6. Connect the 12 V battery.
  7. Ignition ON, observe the scan tool Hybrid Battery Pack Calculated Voltage parameter. Compare the calculated voltage value to the voltage value measured and recorded with the DMM. The voltage values should be within 20 V of each other.
    8. ⇒If not within the specified range, test the 300 V reference circuits for an open/high resistance between the BECM X5 and HV terminals. If all circuits test normal, replace the BECM.
  8. Disconnect the X4 harness connector at the BECM.
  9. Connect the EL-48571 to the X4 harness connector.
  10. Test for 13-19 V across each pair of voltage monitor circuits.
    11. ⇒If not within the specified range, replace the drive motor battery assembly.
  11. If all circuits test normal, replace the BECM.

P0ABC

  1. Verify that DTCs P0A95, P0C77, and P1A20 are not set.
    2. ⇒If any of the specified DTCs are set, diagnose those DTCs first.
  2. Ignition ON, verify the scan tool Hybrid Battery Pack Calculated parameter is greater than 194 Volts.
    3. ⇒If less than the specified value, replace the drive motor generator battery.
  3. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling.
  4. Remove the drive motor generator battery case upper cover, front cover and right side cover. Refer to Drive Motor Battery Case Upper Cover, Front Cover, and Right Side Cover Replacement.
  5. Connect the 12 V battery.
  6. Ignition ON, engine OFF, command the HV positive relay closed with a scan tool. Test for less than 0.5 Ω between the HV+ and HV- terminals of the HV positive contactor relay.
    7. ⇒If greater than the specified value, replace the HV positive contactor relay.
  7. Ignition ON, engine OFF, command the HV negative relay closed with a scan tool. Test for less than 0.5 Ω between the HV+ and HV- terminals of the HV negative contactor relay.
    8. ⇒If greater than the specified value, replace the HV negative relay.
  8. Test for an open/high resistance in the HV DC cables between the HV positive and negative contactor relays and the HV hybrid battery terminals.
    9. ⇒Replace any damaged or open components as required.
  9. Test for an open/high resistance in the HV DC cables between the HV positive and negative contactor relays and the HV terminal block.
    10. ⇒Replace any damaged or open components as required.
  10. Test for an open/high resistance in the HV positive and negative sensor harness between the 300 V terminal block and the BECM X5 connector.
    11. ⇒Replace any damaged or open components as required.
  11. If all circuits test normal, replace the BECM.

P0ABD

  1. Ignition ON, verify the scan tool Hybrid Battery Pack Calculated parameter is less than 430 Volts.
    2. ⇒If greater than the specified range, replace the drive motor generator battery.
  2. If all circuits test normal, replace the BECM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

    •  Drive Motor Battery Negative High Voltage Contactor Relay Replacement
    •  Drive Motor Battery Positive High Voltage Contactor Relay Replacement
    •  Drive Motor Generator Battery Replacement
    •  Control Module References - for BECM replacement, setup and programming.