DTC PZ2152, Loss Of Serial Communications - HVAC Programmer: Testing
WARNING: This page is about a different car, the 1996 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
Ensure HVAC programmer is operating properly. If HVAC programmer is not operating properly, diagnose and repair as necessary. See A/C-HEATER SYSTEM - AUTOMATIC article. If HVAC programmer is okay, check for poor connections at HVAC programmer. If connections are okay, replace HVAC programmer.