853825 Mercury CAP

Table 1
Diagnostic Codes Table    
Description     Conditions which Generate this Code     System Response    
291-5 Engine Cooling Fan Solenoid current below normal     The current is below an acceptable value.     The code is logged.
A warning will appear on the display on the control panel.
The Electronic Control Module (ECM) loses the ability to control the engine cooling fan.
The cooling fan operates at maximum speed.    
291-6 Engine Cooling Fan Solenoid current above normal     The current is above an acceptable value.     The code is logged.
A warning will appear on the display on the control panel.
The ECM loses the ability to control the engine cooling fan.
The cooling fan operates at maximum speed.    The ECM controls the speed of the fan by controlling the current to the fan control solenoid. The fan control solenoid operates a valve that controls the flow of hydraulic fluid to the fan motor. The fan pump defaults to maximum pressure and a diagnostic code is generated if the ECM detects an open or a short in the solenoid circuit.The ECM controls the rpm of the engine fan in order to provide the following benefits:
Increased productivity
Noise from the fan is reduced.
Improved fuel economy
Overcooling of the engine is reduced.The ECM monitors engine coolant temperature and intake manifold air temperature in order to determine the correct fan rpm. When a system fault is detected, fan speed increases to maximum rpm.
Illustration 1 g02472517
Schematic for the cooling fan control for the engine
Illustration 2 g02472536
Pin locations on the P1 connector (P1-43) Cooling fan control (P1-51) Cooling fan returnTest Step 1. Inspect Electrical Connectors and Wiring
Remove the electrical power from the ECM.
Thoroughly inspect the ECM connector J1/P1. Inspect all of the other connectors for the circuit. Refer to service Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque. Refer to service Troubleshooting, "Electrical Connectors - Inspect".
Check the harness and the wiring for abrasion and for pinch points.Expected Result:All connectors, pins, and sockets are correctly coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are correctly coupled.Perform the "Wiggle Test" on the electronic service tool.Use the electronic service tool in order