77248 Mercruiser DECAL, MERCRUISER

Table 1
Diagnostic Trouble Codes for the Cooling Fan Solenoid
J1939 Code CDL Code Code Description Comments
4212-5 291-5 Engine Cooling Fan Solenoid current below normal The Electronic Control Module (ECM) detects the following conditions:
A low current condition in the output from the ECM to the cooling fan solenoid.
There are no active 168 diagnostic codes.
The Alert lamp will come on. The ECM will log the diagnostic code.
This diagnostic code will detect a fault in the circuit for the cooling fan solenoid that is most likely to be an open circuit.
4212-6 291-6 Engine Cooling Fan Solenoid current above normal The ECM detects the following conditions:
A high current condition in the output from the ECM to the cooling fan solenoid.
There are no active 168 diagnostic codes.
The Alert lamp will come on. The ECM will log the diagnostic code.
This diagnostic code will detect a fault in the circuit for the cooling fan solenoid. This problem is most likely to be caused by a high side short to ground or a low side short to power. The following background information is related to this procedure:Viscous Clutch Cooling Fan SolenoidThe viscous clutch cooling fan solenoid controls the engagement of the clutch that drives the engine cooling fan. The ECM determines the desired fan speed based on the ATAAC temperature and the coolant temperature. The viscous clutch cooling fan solenoid is controlled by a PWM signal from the ECM.
Illustration 1 g02484302
View of the connector for the cooling fan solenoid
(3) Cooling fan solenoid return
(4) Cooling fan solenoid controlDuring the following procedure, refer to the electrical schematic for the application.
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the P1/J1 ECM connectors and thoroughly inspect the connector for