MPI Module Fan Keeps Running, or Always Runs at High Speed

NOTE: Information marked with an asterisk (*) applies to the PDUFANH line.

Turn the ignition switch OFF.
Remove the cargo floor mat (see TRIM REMOVAL/INSTALLATION - CARGO AREA ).
Turn the battery module switch OFF (see TURNING OFF POWER TO THE HIGH VOLTAGE CIRCUIT ).
Remove the IPU lid (see TURNING OFF POWER TO THE HIGH VOLTAGE CIRCUIT ).
Disconnect MCM connector A (32P).
Does the MPI module fan run?
1. YES - Go to step 6.
2. NO - Substitute a known-good MCM and recheck. If the symptom/indication goes away, replace the original MCM.
Remove the low speed MPI module fan control relay and high speed MPI module fan control relay.
Check for continuity between body ground and MCM connector terminals A6 and A7*.

Fig 1: Checking Continuity Between Body Ground And MCM Connector Terminals A6 And A7*
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Repair short to ground in the wire between the MCM (A6, A7*) and the low (high)* speed motor MPI module fan control relay.
2. NO - Go to step 8.
Check the low (high)* speed MPI module fan control relay (see POWER RELAY TEST ).
Is the relay OK?
1. YES - Repair short to ground in the wire between the MPI module fan and high speed MPI module fan control relay.
2. NO - Replace the low (high)* speed MPI module fan control relay.