GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Yukon XL - 2WD 🢒 DTC 🢒 DTC P1AE2-P1AE4, P1B05, or P1B06

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 P1AE2: Battery Energy Control Module High Voltage System Interlock Circuit

DTC P1AE3: Battery Energy Control Module High Voltage System Interlock Circuit Low Voltage

DTC P1AE4: Battery Energy Control Module High Voltage System Interlock Circuit High Voltage

DTC P1B05: Drive Motor 1 Control Module High Voltage System Interlock Circuit

DTC P1B06: Drive Motor 2 Control Module High Voltage System Interlock Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

HVIC Source¹

P1B05, P1B06, P1AE3

P1B05, P1B06, P1AE2

P1B05, P1B06, P1AE4

HVIC Return¹

P1AE3

P1B05, P1B06, P1AE2

P1B05, P1B06, P1AE4

¹HVIC source and HVIC return shorted together sets only P1B05 and P1B06.

Typical Scan Tool Data

HVIC Source Current - BECM

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON

Parameter Normal Range: 12 mA¹

HVIC Source

12 mA

0 mA

0 mA

HVIC Return

12 mA

0 mA

0 mA

¹Parameter may vary from a DMM measurement by 6 mA


HVIC Return Current - BECM

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON

Parameter Normal Range: 12 mA¹

HVIC Source

0 mA

0 mA

39 mA

HVIC Return

0 mA

0 mA

39 mA

¹Parameter may vary from a DMM measurement by 6 mA


HPCM HVIC Status - HPCM

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON

Parameter Normal Range: Pass¹

HVIC Source

Fail

Fail

Pass

HVIC Return

Pass

Fail

Fail

¹Parameter indicates Fail whenever high voltage contactor relays are commanded open


BECM HVIC Status - HPCM

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON

Parameter Normal Range: Pass¹

HVIC Source

Fail

Fail

Fail

HVIC Return

Fail

Fail

Fail

¹Parameter indicates Indeterminate whenever high voltage contactor relays are commanded open

Circuit/System Description

The high voltage interlock circuit (HVIC) is utilized to verify high voltage component integrity. HVIC is a circuit loop that passes through certain high voltage components. HVIC is used to determine if access to high voltage components is being attempted. The opening of these high voltage components causes HVIC to open. The battery energy control module (BECM) sources about 12 mA of current on the 5V HVIC loop. The BECM monitors both the HVIC source circuit current and the HVIC return circuit current in order to detect circuit faults. Both motor control modules (MCMs) monitor the circuit for current in order to detect an open condition. When the BECM and/or the MCMs sense conditions such as a loss of HVIC current, the high voltage contactor relays are commanded open by the hybrid powertrain control module (HPCM).

Conditions for Running the DTC

P1B05 and P1B06

    • Ignition voltage is 8-18 volts.
    • Wake up signal is active.
    • BECM is supplying current on HVIC circuit. This normally occurs when HV contactor relays are closed.

P1AE2, P1AE3 and P1AE4

    • Ignition voltage is 9-18 volts.
    • Wake up signal is active.
    • BECM is supplying current on HVIC circuit. This normally occurs when HV contactor relays are closed.

Conditions for Setting the DTC

P1B05 and P1B06

    • The MCM does not detect HVIC current flow.
    • DTC P1B05 and P1B06 set within 1 second when the above condition is met.

P1AE2

    • The BECM detects HVIC source current is less than 5 mA and HVIC return current is less than 5 mA.
    • DTC P1AE2 sets within 1 second when the above condition is met.

P1AE3

    • The BECM detects HVIC source current is between 5-18 mA and HVIC return current is less than 5 mA.
    • DTC P1AE3 sets within 1 second when the above condition is met.

P1AE4

    • The BECM detects HVIC source current is less than 5 mA and HVIC return current is greater than 35 mA.
    • DTC P1AE4 sets within 1 second when the above condition is met.

Action Taken When the DTC Sets
    • DTCs P1B05, P1B06, P1AE2, P1AE3, P1AE4 are Type C DTCs.
    • The HPCM commands the BECM to open the high voltage contactor relays when vehicle speed is less than 5 km/h (3 mph) for 6 seconds.

Conditions for Clearing the DTC

DTCs P1B05, P1B06, P1AE2, P1AE3, P1AE4 are Type C DTCs.

Diagnostic Aids
    • Test for a fully engaged high voltage manual disconnect lever whenever an open HVIC condition is observed. The manual disconnect lever must be pressed down fully in order to engage the HVIC terminals.
    • The BECM HVIC source and HVIC return circuit current sensors may not measure actual circuit current with the same accuracy. The BECM HVIC Source parameter may indicate less current than the BECM HVIC Return parameter for this reason. Measuring actual HVIC current with a DMM may also not compare directly to the parameter display.
    • The HVIC detects removal of the following components:
       - The drive motor generator control module sight shield
       - The transmission 3 phase cable cover
       - The high voltage manual disconnect lever
       - The hybrid battery terminal extension cover assembly
    • The HVIC is also routed through several inline connectors.
    • With the ignition in the OFF position, the BECM will source the HVIC current for 5 minutes every time a vehicle door is opened.

Reference Information

Schematic Reference

Hybrid Controls Schematics

Connector End View Reference

Component Connector End Views

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

Circuit/System Verification

    Important: The HPCM must command the high voltage contactor relays closed in order for HVIC to be enabled. Fail will be displayed if any DTCs present at ignition ON prevent the HPCM from closing the high voltage contactor relays.

  1. Capture and then clear the DTC information.
  2. Ignition OFF, wait 2 minutes.
  3. Ignition ON, observe the HPCMs BECM HVIC Status and HPCM HVIC Status parameters.
    4. ⇒The parameters should both indicate a PASS condition.

Circuit/System Testing

P1B05 and P1B06 without P1AE2, P1AE3 or P1AE4

    Important: DTC P1B05 and P1B06 should always pass and fail together. If one DTC has passed while one has failed, replace the drive motor generator power inverter control module (PIM).

  1. Ignition OFF, wait 2 minutes.

    2. Important: The drive motor generator control module sight shield must be installed during all testing in order to complete the HVIC current loop.

  2. Disconnect PIM connector X1.
  3. Ignition ON, observe the BECM HVIC Current Source parameter.
    4. ⇒If the HVIC Current Source parameter indicates current less than 5 mA, replace the PIM.
    ⇒If the HVIC Current Source parameter indicates current between 5-18 mA test for the HVIC Source and HVIC Return circuits shorted together between PIM connector X1 and X350.

    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.

    Important: Removal of the HV manual disconnect lever also opens the HVIC source circuit between X350 and BECM connector X1.

    ⇒If the circuit tests normal, perform the High Voltage Disabling procedure and test for the HVIC Source and HVIC Return circuits shorted together between X350 and BECM connector X1. If the circuit tests normal, replace the BECM.

P1B05 and P1B06 with P1AE2

    Important: DTCs P1B05 and P1B06 should always pass and fail together. If one DTC has passed while one has failed, replace the drive motor generator power inverter control module (PIM).

  1. Ignition OFF, wait 2 minutes.

    2. Important: The drive motor generator control module sight shield must be installed during all testing in order to complete the HVIC current loop.

  2. Disconnect PIM connector X1.
  3. Install a 3 A fused jumper wire between the HVIC return circuit terminal 1 and the HVIC source circuit terminal 23.
  4. Ignition ON, observe the BECM HVIC Source Current parameter.
    5. ⇒If the HVIC Source Current parameter indicates current between 5-18 mA, test for proper PIM connector X1 terminal contact at terminal 1 and terminal 23. If the terminal contact tests normal, replace the PIM.
  5. Remove the PIM terminal 1 to terminal 23 fused jumper wire.
  6. Test for 5-18 mA with a DMM between the HVIC Source circuit terminal 23 and ground.
    7. ⇒If within the specified range, test the HVIC Return circuit for an open between PIM connector X1 and X350.

    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.

    ⇒If the circuit tests normal, perform the High Voltage Disabling procedure and test the HVIC Return circuit for an open between X350 and BECM connector X1. If the circuit tests normal, replace the BECM.
    ⇒If less than the specified range, test the HVIC Source circuit for an open between PIM connector X1 and X350.

    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.

    Important: Removal of the HV manual disconnect lever also opens the HVIC source circuit between X350 and BECM connector X1.

    ⇒If the circuit tests normal, perform the High Voltage Disabling procedure and test the HVIC Source circuit for an open between X350 and BECM connector X1. If the circuit tests normal, replace the BECM.

P1AE3 with or without P1B05 and P1B06

    Important: DTCs P1B05 and P1B06 should always pass and fail together. If one DTC has passed while one has failed, replace the drive motor generator power inverter control module (PIM).

  1. Ignition OFF, wait 2 minutes.

    2. Important: The drive motor generator control module sight shield must be installed during all testing in order to complete the HVIC current loop.

  2. Disconnect PIM connector X1.
  3. Ignition ON, observe the BECM HVIC Source Current parameter. The parameter should display less than 5 mA.
    4. ⇒If the HVIC Source Current parameter indicates current between 5-18 mA test the HVIC Source circuit for a short to ground between PIM connector X1 and X350.

    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.

    Important: Removal of the HV manual disconnect lever also opens the HVIC source circuit between X350 and BECM connector X1.

    ⇒If the circuit tests normal, perform the High Voltage Disabling procedure and test the HVIC Source circuit for a short to ground between X350 and BECM connector X1. If the circuit tests normal, replace the BECM.
  4. Install a 3A fused jumper wire between the HVIC return circuit terminal 1 and the HVIC Source circuit terminal 23.
  5. Observe the BECM HVIC Source Current and HVIC Return Current parameters with the scan tool.
    6. ⇒If both HVIC Source Current and HVIC Return Current parameters indicate current between 5-18 mA, replace the PIM.
    ⇒If only the HVIC Source Current parameter indicates current between 5-18 mA test the HVIC Return circuit for a short to ground between PIM connector X1 and X350.

    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.

    ⇒If the circuit tests normal, perform the High Voltage Disabling procedure and test the HVIC Return circuit for a short to ground between X350 and BECM connector X1. If the circuit tests normal, replace the BECM.

P1AE4 with or without P1B05 and P1B06

    Important: DTCs P1B05 and P1B06 should always pass and fail together. If one DTC has passed while one has failed, replace the drive motor generator power inverter control module (PIM).

  1. Ignition OFF, wait 2 minutes.

    2. Important: The drive motor generator control module sight shield must be installed during all testing in order to complete the HVIC current loop.

  2. Disconnect PIM connector X1.
  3. Ignition ON, test for less than 35 mA with a DMM between the HVIC Source circuit terminal 23 and ground.
    4. ⇒If more than the specified range, test the HVIC Source circuit for a short to voltage between PIM connector X1 and X350.

    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.

    Important: Removal of the HV manual disconnect lever also opens the HVIC source circuit between X350 and BECM connector X1.

    ⇒If the circuit tests normal, perform the High Voltage Disabling procedure and test the HVIC Source circuit for a short to voltage between X350 and BECM connector X1. If the circuit tests normal, replace the BECM.
  4. Ignition ON, test for less than 35 mA with a DMM between the HVIC Return circuit terminal 1 and ground.
    5. ⇒If more than the specified range, test the HVIC Return circuit for a short to voltage between PIM connector X1 and X350.

    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.

    ⇒If the circuit tests normal, perform the High Voltage Disabling procedure and test the HVIC Return circuit for a short to voltage between X350 and BECM connector X1. If the circuit tests normal, replace the BECM.
  5. If all circuits test normal, replace the PIM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PIM or BECM replacement, setup, and programming