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 P1A04: Battery Energy Control Module Programming Read Only Memory (ROM)DTC P1A05: Battery Energy Control Module Random Access Memory (RAM)
DTC P1A06: Battery Energy Control Module Read Only Memory (ROM)
DTC P1A08: Battery Energy Control Module Stack Overrun
Circuit/System Description
The battery energy control module (BECM) monitors to detect an RAM, ROM, EPROM or controller stack over run. If a fault is detected, the appropriate DTC will set.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
P1A04, P1A06
Checksum does not match.
P1A05
Error during write to a location in RAM.
P1A08
Number of Over Runs is greater than 0.
Action Taken When the DTC Sets
Hybrid system is disabled.
Conditions for Clearing the DTC
P1A04
State = System Powerup.
P1A05, P1A06, P1A08
State = Run or Service or Powerdown or Powerup.
Reference Information
Schematic Reference
Hybrid Energy Storage Schematics
Connector End View Reference
Description and Operation
Generator Battery Carrier Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Warning: To help avoid personal injury, additional precautions must be taken prior to working on the generator control module or the generator starter. After removing the 36V battery cables from the generator battery, remove both engine wiring harness connectors from the generator control module. Wait at least 5 minutes and then remove the generator control module cover. Verify voltage levels at all 36V, 12V, and 3-phase connections, are less than 3 volts using a DMM before proceeding.
Warning: To help avoid personal injury, be careful when working in the vicinity of the generator battery disconnect control module. Internal components will still be live, 36V potential, even when the cover has been opened or removed.
- Inspect for poor 12 volt and ground connections at the 12 volt vehicle body harness at the BECM.
- If DTC is history, review the vehicle service history, to verify if the vehicle has been serviced for low battery concern in the past.
- If DTC resets as current, replace the BECM.
| ⇒ | If the service history did not indicate the above concern clear codes. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for BECM replacement, setup, and programming
