Action Taken When the DTC Sets
* The driver information center (DIC) displays the message Service Hybrid System.
* Multiple DTCs may set depending on the fault location and when the fault occurred.
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.
Diagnostic Aids
A false DTC U1812 can set if the engine does not crank while the ignition key is held in the start position for greater than 3 seconds. Diagnose the
engine does not crank condition first.
Reference Information
Schematic Reference
* Data Communication Schematics (See: Powertrain Management/Computers and Control Systems/Information Bus/Diagrams/Electrical
Diagrams)
* Hybrid Controls Schematics ()
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Data Link Communications Description and Operation (See: Powertrain Management/Computers and Control Systems/Information
Bus/Description and Operation)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Circuit/System Verification
1. Verify that DTC U1862 is not set in the HPCM.
锟斤拷If the DTC is set, refer to DTC U1862 (See: U Code Charts/U1862).
2. Verify that DTC B137A is not set in the SDG module.
锟斤拷If the DTC is set, refer to DTC B137A (See: B Code Charts/B137A).
Circuit/System Testing
1. Ignition OFF, disconnect the inline harness connector X350 at the drive motor generator battery.
2. Ignition ON, verify that a test lamp illuminates between the wake up signal circuit terminal 10 X350 and ground.
锟斤拷If the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuit tests normal, replace the SDG module.
锟斤拷If the test lamp illuminates, test the wake up signal circuit of the drive motor generator battery control module electrical harness for an
open/high resistance.
3. If all circuits test normal, replace the drive motor generator battery control module.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for module replacement, setup, and programming
