Radiator and A/C Condenser Fan Low Speed Circuit Troubleshooting
NOTE:
  • Do not use this troubleshooting procedure if the A/C compressor is inoperative. Refer to the symptom troubleshooting index.
  • Before performing symptom troubleshooting, check for powertrain DTCs, R20A3 engine model, K24Z3 engine model.
  1. Check the No. 3−6 (MAIN FAN MTR) (30 A) fuse in the under-hood fuse/relay, and the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box.
Are you fuses OK?
YES -
Go to Step 2 .
NO -
Replace the fuse(s), and recheck. If the fuse(s) blow again, check for a short in the No. 3−6 (MAIN FAN MTR) (30 A) fuse and the No. 16 (7.5 A) fuse circuits.■
Is the relay OK?
YES -
Go to Step 3 .
NO -
Replace the radiator fan relay .■
  1. Measure the voltage between the radiator fan relay 4P socket No. 1 terminal and body ground.
Is there battery voltage?
YES -
Go to Step 4 .
NO -
  1. Connect the radiator fan relay 4P socket No. 1 and No. 2 terminals with a jumper wire.
Does the radiator and A/C condenser fans run on low?
YES -
Go to Step 5 .
NO -
Go to Step 14 .
  1. Disconnect the jumper wire.
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between the radiator fan relay 4P socket No. 4 terminal and body ground.
Is there battery voltage?
YES -
Go to Step 8 .
NO -
Go to Step 32 .
  1. Turn the ignition switch to LOCK (0).
  1. Reinstall the radiator fan relay.
  1. Jump the SCS line with the HDS.
    NOTE: This step must be done to protect the engine/powertrain control module (ECM/PCM) from damage.
  1. Disconnect ECM/PCM connector A (44P) (R20A3 engine model) or ECM/PCM connector A (49P) (K24Z3 engine model).
  1. Connect the ECM/PCM connector A (44P) No. 4 terminal (R20A3 engine model) or ECM/PCM connector A (49P) No. 5 terminal (K24Z3 engine model) to body ground with a jumper wire.
  1. Turn the ignition switch to ON (II).
Do the radiator and A/C condenser fans run on low?
YES -
Check for loose wires or poor connections at ECM/PCM connector A (44P) No. 4 terminal (R20A3 engine model) or ECM/PCM connector A (49P) No. 5 terminal (K24Z3 engine model). If the connections are good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM, R20A3 engine model, K24Z3 engine model. ■
NO -
Repair open in the wire between the radiator fan relay and the ECM/PCM.■
  1. Disconnect the jumper wire.
  1. Reinstall the radiator fan relay.
  1. Disconnect the radiator fan 2P connector.
  1. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.
  1. Measure the voltage between the radiator fan 2P connector No. 2 terminal and body ground.
Is there battery voltage?
YES -
Go to Step 19 .
NO -
Repair open in the wire between the radiator fan relay and the radiator fan.■
  1. Set the A/C button and fan control button OFF, then turn the ignition switch to LOCK (0).
  1. Reconnect the radiator fan 2P connector.
  1. Connect the radiator fan 2P connector No. 1 terminal to body ground with a jumper wire.
  1. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.
Does the A/C condenser fan run at high speed?
YES -
Go to Step 23 .
NO -
  1. Set the A/C button and fan control button to OFF, then turn the ignition switch to LOCK (0).
  1. Disconnect the jumper wire.
Is the relay OK?
YES -
Go to Step 26 .
NO -
Replace the relay circuit board.■
  1. Check for continuity between under-hood fuse/relay box connector B (14P) No. 11 terminal and the radiator fan 2P connector No. 1 terminal.
Is there continuity?
YES -
Go to Step 27 .
NO -
Repair open in the wire between the under-hood fuse/relay box and the radiator fan.■
  1. Reconnect under-hood fuse/relay box connector B (14P) and the radiator fan 2P connector.
  1. Disconnect the A/C condenser fan 2P connector.
  1. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.
  1. Measure the voltage between the A/C condenser fan 2P connector No. 2 terminal and body ground.
Is there battery voltage?
YES -
Go to Step 31 .
NO -
Repair open in the wire between the fan control relay and the A/C condenser fan.■
  1. Measure the voltage between the A/C condenser fan 2P connector No. 1 and No. 2 terminals.
Is there battery voltage?
YES -
NO -
Check for an open in the wire between the A/C condenser fan and body ground. If the wire is OK, check for poor ground at G301, LHD model, RHD model. ■
  1. Turn the ignition switch to LOCK (0).
  1. Using the diode setting ( ) on a DVOM, check for current flow in both directions between relay circuit board connector B (14P) No. 2 and No. 10 terminals.
Is there current flow in only one direction?
YES -
Go to Step 35 .
NO -
Replace the relay circuit board.■
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between under-hood fuse/relay box connector B (14P) No. 2 terminal and body ground.
Is there battery voltage?
YES -
NO -
Repair open in the wire between the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box and under-hood fuse/relay box.■