Table 1. 291 Demand Fan Solenoid Diagnostic Codes - Continued.
CID FMI CODE
TEST OR INSPECTION
291-6 Demand Fan Solenoid
Current Above Normal
· Always inspect wiring harness connectors that are involved in the circuit.
Poor connections can often be the cause of a problem in an electrical
circuit. Verify that all connections in the circuit are clean and secure and
that all connections are in good condition. If a problem with the
connection is found, correct the problem and verify that this malfunction
or diagnostic code is active before performing this procedure.
· Perform open or short-circuit test at each wiring harness connection to
identify the correct wiring harness to replace.
· Tag all wiring harnesses to aid in installation.
· Perform this test only if condition is active.
DIAGNOSTIC CODE SET CONDITION
Transmission ECM detects a short circuit or high current condition in the demand
· Lower cab wiring harness shorted to ground.
· Rear frame wiring harness shorted to ground.
Test Step 1. Check for Active
Connect MSD. Select Transmission
Diagnostic Code 291-6 Active -
Proceed to Test Step 2.
924H and check for active diagnostic
Diagnostic Code 291-6 Not Active -
Troubleshooting is complete.
Test Step 2. Test for Faulty Demand
1. Turn ignition switch and battery
disconnect switch to OFF position
2. Remove fan (WP 0234).
3. Disconnect connector M-C16
demand fan solenoid.
4. Turn ignition switch and battery
disconnect switch to ON position