B137A
DTC B137A
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC B137A 01
- Hybrid Accessory Wake Up Circuit - Short to Battery
DTC B137A 06
- Hybrid Accessory Wake Up Circuit - Short to Ground or Open
Diagnostic Fault Information
Circuit/System Description
Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.
The wake up signal circuit is energized by the serial data gateway module (SDGM) to activate the drive motor generator power inverter module (PIM) and the drive motor generator battery control module (BECM) immediately when the body control module (BCM) signals the SDGM that serial data is required.
Conditions for Running the DTC
* The system voltage is between 9-16 volts.
* The vehicle power mode master requires serial data communication to occur.
Conditions for Setting the DTC
A short to ground exists on the wake up signal circuit of the SDGM.
Action Taken When the DTC Sets
The malfunction indicator lamp (MIL) will illuminate and several driver information center (DIC) messages will scroll.
Conditions for Clearing the DTC
* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
Reference Information
Schematic Reference
* Data Communication Schematics (Electrical Diagrams)
* Control Module References (Programming and Relearning)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Data Link Communications Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Special Tools
* EL-48569 Terminal Covers
* EL-48900 HEV Safety Kit
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.
1. Perform the Hybrid Battery Service Disconnect/Connect () procedure.
2. Reconnect the 12-volt battery.
3. Ignition OFF, disconnect harness connector X1 of the BECM and the PIM.
4. Ignition ON, verify that a test lamp illuminates between the wake up signal circuit of the PIM and ground, and the BECM and ground as follows:
* PIM X1 19
* BECM X1 12
• If the test lamp does not illuminate, test the circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the SDGM.
5. Ignition OFF, verify that a test lamp does not illuminate between the PIM wake up signal circuit terminal 19 and ground.
• If the test lamp illuminates, test the circuit for a short to voltage. If the circuit tests normal, replace the SDGM.
6. If all circuits test normal, replace the SDGM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning)for module replacement, setup, and programming