Radiator and A/C Condenser Fan Low Speed Circuit Troubleshooting
NOTE: Before doing any symptom troubleshooting, check for powertrain DTCs.
  1. Check the No. 18 (20 A) fuse in the under-hood fuse/relay box, and the No. 36 (10 A) fuse in the under-dash fuse/relay box.
Are the fuses OK?
YES -
Go to Step 2 .
NO -
Replace the fuses, and recheck. If fuses blow again, check for a short in the No. 18 (20 A) and No. 36 (20 A) fuses circuit.■
  1. Connect the HDS to the DLC.
  1. Turn the ignition switch ON (II).
  1. Turn on the A/C on the heater control unit.
  1. Check the FAN LOW CTRL in the PGM-FI Data List with the HDS.
Is the FAN LOW CTRL on?
YES -
Go to Step 6 .
NO -
Substitute a known-good ECM, and retest. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
  1. Turn the ignition switch OFF.
  1. Jump the SCS line with the HDS.
    NOTE: This step must be done to protect the engine control module (ECM) from damage.
  1. Disconnect ECM connector A (44P).
  1. Turn the ignition switch ON (II).
  1. Measure the voltage between ECM connector A (44P) terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to Step 11 .
NO -
Repair open in the wires between the under-hood fuse/relay box and the ECM, or between the No. 36 (10 A) fuse in under-dash fuse/relay box and the under-hood fuse/relay box. If wires are OK, replace the under-hood fuse/relay box. ■
  1. Turn the ignition switch OFF.