Circuit/System Verification

WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON, observe the scan tool ECM engine coolant temperature (ECT) parameter in freeze frame data. The reading should be below 125°C (257°F).
- If the ECT was above 125°C (257°F) when the DTC set, go to Symptoms - Engine Cooling and correct that concern first.
Inspect for proper coolant level in the hybrid cooling system reservoir.
- If coolant level is low refer to Generator Control Module Cooling System Draining and Filling .
Inspect the hybrid cooling system radiator for debris or obstruction.
- If a concern is found, repair or replace the restricted or damaged components as necessary.
Inspect for proper operation of all hybrid system coolant pumps. Refer Hybrid Cooling System Overheating (Electrical) .
- If a concern is found, repair or replace the coolant pumps as necessary.
Command the cooling fans through all operating speeds.
- If the cooling fans do not operate in all speeds, refer to Cooling Fan Inoperative (without HP2) , Cooling Fan Inoperative (with HP2) .
If the above inspections do not identify a concern, disassemble the T6 drive motor generator power inverter module and inspect the drive motor generator power inverter module cooling surface for excessive corrosion or contamination restriction. Refer to Drive Motor Generator Power Inverter Module Removal and Installation .
- If corrosion or contamination is found, clean the drive motor generator power inverter module cooling surface or replace the T6 drive motor generator power inverter module as necessary.