• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
B+ | P0A82 | P0A82 | -- | -- |
Fan Control | P0A81, P0A83 | P0A81, P0A82 | P0A81 | -- |
The battery energy control module (BECM) monitors to detect if the cooling fan is enabled, in the stuck off position or in the stuck on condition. If a failure is detected, the appropriate DTC will set.
The engine is running.
• | Enable flag is enabled. |
• | Fan state is OFF. |
• | Fan speed feedback is less than 5 percent. |
• | Fan state is ON. |
• | Fan speed feedback is greater than 5 percent. |
• | Fan state is OFF. |
The hybrid system is disabled.
The fan is not enabled.
The fan speed feedback is normal.
Starter Generator Control Module Cooling System Description and Operation
• | Circuit Testing |
• | Wiring Repairs |
Control Module References for scan tool information
J 35616 GM Approved Terminal Test Kit
Ignition ON, using the scan tool special function command the hybrid cooling fan ON and OFF several times.
⇒ | If the cooling fan does not operate as commanded, continue with Circuit/System Testing. |
Caution: 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.
Important: In order to avoid damaging BECM X1 and X2 connector terminals, the proper test probes should be used. The proper test probes are as follows:
• | J-35616-65B for female terminals |
• | J-35616-64B for male terminals |
⇒ | If the circuit tests normal, replace the BECM. |
⇒ | If the fan operates, replace the BECM. |
• | BECM X2 connector terminal 2 to cooling fan harness connector terminal 1 |
• | BECM X2 connector terminal 4 to cooling fan harness connector terminal 2 |
• | BECM X2 connector terminal 3 to cooling fan harness connector terminal 3 |
• | BECM X2 connector terminal 11 to cooling fan harness connector terminal 4 |
⇒ | If all circuits test normal, replace the hybrid battery pack cooling fan. |
⇒ | If the circuit tests normal, replace the BECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BECM replacement, setup, and programming |