C15 – 0121-05 Low/High Retarder current low (14)

Conditions Which Generate This Code:

The Engine Control Module (ECM) detects the following conditions:
• The ECM detects a low current condition (open circuit) for one second while the ECM is attempting to energize the solenoid for cylinder 3 and cylinder 4.
• The engine retarder switch is in the Low or High position.

System Response:
The ECM will log the diagnostic code and the ECM will trigger a snapshot. The check engine lamp will illuminate while this diagnostic code is active.

Possible Performance Effect:
The engine retarder may not activate.


Perform the following diagnostic procedure:
“Retarder (Compression Brake) Solenoid Circuit – Test”

• OK – STOP.

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