(Hybrid) Supplement to Generator Control Module Cooling System Draining and Filling Procedure - keywords gcm replace replacement

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

The Generator Control Module (GCM - Also known as the PIM - Power Inverter Module) Cooling System Draining and Filling Procedure in SI states: Use pre-mixed Dexcool only. Pre-mix DEXCOOL contains the proper 50/50 mixture of DEXCOOL and de-ionized water necessary to prevent corrosion damage to the generator control module internal heat sink. Never use tap water in the hybrid cooling system.

However, GMSPO does not offer pre-mixed Dexcool at this time.

Until pre-mixed Dexcool is available through GMSPO it is acceptable to use another brand of pre-mixed/ready-to-use Dexcool, such as Zerex or Prestone, which can be obtained from a local supplier.

If pre-mixed/ready-to-use Dexcool is not available from a local supplier, it is acceptable to fill the system with a 50/50 solution of de-ionized/distilled water and standard Dexcool but do not use tap water because it will cause internal GCM/PIM corrosion and failure in a short period of time.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.