Motor Power Inverter (MPI) Module Fan Does Not Run

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 ).
Connect MCM connector terminal A6 to body ground with a jumper wire.

Fig 1: Connecting MCM Connector Terminal A6 To Body Ground Using Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Does the MPI module fan run?
1. YES - Go to step 6.
2. NO - Go to step 7.
Connect MCM connector terminals A6 and A7 to body ground with jumper wires.

Fig 2: Connecting MCM Connector Terminals A6 And A7 To Body Ground Using Jumper Wires
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Does the MPI module fan run at high speed?
1. YES - The MPI module fan is OK.
2. NO - Go to step 15.
Check the low speed MPI module fan control relay (see POWER RELAY TEST ).
Is the relay OK?
1. YES - Go to step 8.
2. NO - Replace the low speed MPI module fan control relay.
Disconnect MCM connector A (32P) and the low speed MPI module fan control relay 4P connector.
Connect low speed MPI module fan control relay 4P connector terminal No. 3 to body ground with a jumper wire.

Fig 3: Connecting Low Speed MPI Module Fan Control Relay 4P Connector Terminal No. 3 To Body Ground Using Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between body ground and MCM connector terminal A6.

Fig 4: Checking Continuity Between Body Ground And MCM Connector Terminal A6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 11.
2. NO - Repair open in the wire between the MCM (A6) and the low speed MPI module fan control relay.
Measure voltage between body ground and low speed MPI module fan control relay 4P connector terminals No. 2 and No. 4 individually.

Fig 5: Measuring Voltage Between Body Ground And Low Speed MPI Module Fan Control Relay 4P Connector Terminals No. 2 And 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 12.
2. NO - Check for:
  - A blown No. 5 IMA FAN (15 A) fuse in the under-hood fuse/relay box.
  - An open in the wire between the No. 5 IMA FAN (15 A) fuse in the under-hood fuse/relay box and the low speed MPI module fan control relay.
Disconnect the MPI module fan 2P connector.
Connect MPI module fan 2P connector terminal No. 1 to body ground with a jumper wire.

Fig 6: Connecting MPI Module Fan 2P Connector Terminal No. 1 To Body Ground Using Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between body ground and low speed MPI module fan control relay 4P connector terminal No. 1.

Fig 7: Checking Continuity Between Body Ground And Low Speed MPI Module Fan Control Relay 4P Connector Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Substitute a known-good MCM and MPI module fan, and recheck. If the symptom/indication goes away, replace the original MCM and the MPI module fan.
2. NO - Repair open in the wire between the MPI module fan and the low speed MPI module fan control relay.
Check the high speed MPI module fan control relay (see POWER RELAY TEST ).
Is the relay OK?
1. YES - Go to step 16.
2. NO - Replace the high speed MPI module fan control relay.
Disconnect MCM connector A (32P) and the high speed MPI module fan control relay 4P connector.
Connect high speed MPI module fan control relay 4P connector terminal No. 3 to body ground with a jumper wire.

Fig 8: Connecting High Speed MPI Module Fan Control Relay 4P Connector Terminal No. 3 To Body Ground Using Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between body ground and MCM connector terminal A7.

Fig 9: Checking Continuity Between Body Ground And MCM Connector Terminal A7
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 19.
2. NO - Repair open in the wire between the MCM (A7) and the high speed MPI module fan control relay.
Measure voltage between body ground and high speed MPI module fan control relay 4P connector terminal No. 4.

Fig 10: Measuring Voltage Between Body Ground And High Speed MPI Module Fan Control Relay 4P Connector Terminal No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 20.
2. NO - Check for:
  - A blown No. 5 IMA FAN (15 A) fuse in the under-hood fuse/relay box.
  - An open in the wire between the No. 5 IMA FAN (15 A) fuse in the under-hood fuse/relay box and the high speed MPI module fan control relay.
Check for continuity between body ground and high speed MPI module fan control relay 4P connector terminal No. 1

Fig 11: Checking Continuity Between Body Ground And High Speed MPI Module Fan Control Relay 4P Connector Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 21.
2. NO - Repair open in the wire between G502 and the high speed MPI module fan control relay.
Disconnect the MPI module fan 2P connector.
Connect MPI module fan 2P connector terminal No. 2 to body ground with a jumper wire.

Fig 12: Connecting MPI Module Fan 2P Connector Terminal No. 2 To Body Ground Using Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between body ground and high speed MPI module fan control relay 4P connector terminal No. 2.

Fig 13: Checking Continuity Between Body Ground And High Speed MPI Module Fan Control Relay 4P Connector Terminal No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Substitute a known-good MCM and MPI module fan, and recheck. If the symptom/indication goes away, replace the original MCM and the MPI module fan.
2. NO - Check for:
  - An open in the wire between the MPI module fan control resistor and the high speed MPI module fan relay.
  - An open in the wire between the MPI module fan control resistor and the MPI module fan.
  - An open in the wire between the MPI module fan control resistor and G502.
  - Replace the MPI module fan control resistor.