Operation CHARM: Car repair manuals for everyone.
Home >> Chevrolet >> 2010 >> Silverado 1500 4WD V8-6.0L Hybrid >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P1AE7

P1AE7




DTC P1AE6 or P1AE7

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 Descriptors
DTC P1AE6
- Battery Energy Control Module Hybrid Battery Voltage Isolation Sensor Circuit

DTC P1AE7
- Battery Energy Control Module Hybrid Battery Voltage System Isolation Lost

Circuit/System Description

The drive motor generator battery control module is also referred to as the battery energy control module (BECM). The drive motor generator battery control module will diagnose its own systems and determine when a fault condition is present. Diagnostics and system status is communicated from the drive motor generator battery control module to the hybrid powertrain control module (HPCM) through serial data. The hybrid powertrain control module is the host controller for diagnostic trouble code (DTC) information.

The vehicle is equipped with a high voltage isolation monitor feature. The purpose of the high voltage isolation circuit is to test the resistance between the high voltage positive and negative direct current (DC) bus and chassis ground. The drive motor generator battery control module only runs this test when the ignition transitions from ON to OFF and the high voltage contactor relays have opened. The drive motor generator battery control module has an internal isolation sensor that measures the resistance between the high voltage DC positive and negative bus and chassis ground. The drive motor generator battery control module runs an internal self check of this sensor circuit. If the internal self check fails DTC P1AE6 will set. The drive motor generator battery control module sends an AC signal over the DC bus and monitors its amplitude. A low amplitude or collapsed return signal indicates a loss of resistance to chassis ground and a loss of isolation will be indicated by the drive motor generator battery control module. This DTC indicates that the fault is in the drive motor generator battery. Because this diagnostic runs after system power down, the diagnostic status does not get reported until the next key cycle.

Conditions for Running the DTC

* Ignition voltage is 9-18 V.
* The ignition switch transitions from ON to OFF.
* High voltage contactor transitions to open.

Conditions for Setting the DTC

P1AE6

The isolation resistance sensor circuit internal to the drive motor generator battery control module has failed its functional test.

P1AE7
* The drive motor generator battery control module has detected a loss of isolation between the high voltage positive or negative bus to chassis ground that is less than 200 k ohm.
* This diagnostic may take up to 40 seconds to run after the conditions for running have been met. This DTC will not report the status until the next key cycle.

Action Taken When the DTC Sets

DTCs P1AE6 and P1AE7 are Type C DTCs.

Conditions for Clearing the DTC

DTCs P1AE6 and P1AE7 are Type C DTCs.

Diagnostic Aids

A single high voltage contactor relay stuck closed can set this DTC.

Reference Information
Schematic Reference

Hybrid Energy Storage Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
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)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information
Special Tools

EL-48900 HEV Safety Kit

Circuit/System Verification

1. Ignition ON, Verify that DTC P1A1F is not set.

• If the DTC is set, refer to DTC P1A1F or P1A4E (P1A1F).

2. Verify that DTC P1AE6 is not set.

• If the DTC is set, replace the drive motor generator battery control module.

3. Observe the scan tool 300 V Isolation Test Status parameter. The reading should display Passed.
4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

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.


Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:


* Safety glasses with appropriate side shields when within 50 feet of the vehicle, either indoors or outdoors.

* Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors.


- Visually and functionally inspect the gloves before use.

- Wear the Insulation gloves at all times when working with the high voltage battery assembly, whether the system is energized or not.


Failure to follow the procedures exactly as written may result in serious injury or death.


1. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling (High Voltage Disabling).
2. Test for infinite resistance between the terminals listed below and ground;

* positive contactor terminal X2
* positive contactor terminal X3
* negative contactor terminal X2
* negative contactor terminal X3

• If less than the specified value, replace the high voltage cable.

3. Test for less than 1 ohm between the terminals listed below;

* B+ (300 V) and positive contactor terminal X2
* Ground (300 V) and negative contactor terminal X2
* positive contactor terminal X3 and positive cable terminal X1
* negative contactor terminal X3 and negative cable terminal X2

• If greater than the specified range, replace the high voltage cable.

4. Connect the 12 V battery.
5. Ignition ON, command the negative and positive contactors and the current limit relay ON and OFF with a scan tool. Listen for the contactors and relay to turn ON and OFF.

• If the negative contactor, positive contactor or the current limit relay does not turn ON and OFF, refer to High Voltage Contactor/Relay Malfunction (High Voltage Contactor/Relay Malfunction).

6. If all the circuit tests normal, replace the drive motor generator battery.

Repair Instructions

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

* Drive Motor Battery Negative Relay Cable Replacement (Drive Motor Battery Negative Relay Cable Replacement)
* Drive Motor Battery Positive Relay Cable Replacement (Drive Motor Battery Positive Relay Cable Replacement)
* Drive Motor Battery Positive and Negative Cable Replacement (Drive Motor Battery Positive and Negative Cable Replacement)
* Drive Motor Generator Battery Replacement and Shipping Preparation (Drive Motor Generator Battery Replacement and Shipping Preparation)
* Control Module References (Programming and Relearning) for drive motor generator battery control module replacement, setup and programming

pro multis · About Operation CHARM