DTC P1602 Buick
CEM Lost Communication With Headlamp Leveling Control Module. General Failure Information
CEM Lost Communication With Headlamp Leveling Control Module. General Failure Information
Description
The control modules communicate with each other for exchange of information in a network via a standardized serial communication procedure - CAN (Controller Area Network). The diagnostic trouble code (DTC) is stored if the control module detects that: Interrupted or no communication with the Headlamp Control Module (HCM). The control modules test for the diagnostic trouble code (DTC) starts in the event of: Ignition switch position I and II. Note! The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met. The diagnostic trouble code (DTC) indicates a fault in the communication across the CAN network and does not isolate an individual node. Do not replace the central electronic module (CEM) unless fault-tracing indicates a damaged control module.
Cause and Solution
Voltage feed to Headlight Control Module (HCM) missing.Open circuit on ground cable to Headlight Control Module (HCM)Contact resistance in the terminals.Open-circuit or short-circuit in the wiring for the control area network (CAN).Headlight Control Module (HCM) not intended for this car, e. g. , used control module with other hardware software.
Video Guide
Diagnostic Info
- DTC Code: P1602
- Brand: Buick