Diagnostic Aids

If Codes 21 or 25 exist, service them first. Code 52 will set if ABS cannot relieve enough brake pressure to allow wheel to regain speed during ABS stop. Possible causes are seized wheel or skidding sideways during ABS stop. Using Service Stall System (SSS), perform motor solenoid functional test to check ABS operation.

Fig 1: Code 52 - Schematic

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 52 - Diagnostic Flowchart

Courtesy of GENERAL MOTORS CORP.