DTC Test No. 71: High Speed Radiator Fan Control Relay Circuit

NOTE: During actuator test No. 62, high speed fan will turn on and off approximately every 0.7 second.

NOTE: Circuit is monitored when ignition is on and battery voltage is 10 volts or more. DTC is set when an open or short circuit condition is detected in high speed radiator fan relay control circuit for 3 seconds. Possible causes for DTC to set are: relay coil open or shorted, ignition switch output circuit open, relay control circuit open or shorted or defective PCM.

Turn ignition on. Using scan tool, actuate high speed fan relay (actuator test No. 62). If radiator fan does not operate at high speed, go to next step. If radiator fan operates at high speed, failure is intermittent. See INTERMITTENT MALFUNCTION .
Disconnect Powertrain Control Module (PCM) harness connectors. PCM is located at left front corner of engine compartment, in front of Electronic Automatic Transmission Electronic Control Module (EATX-ECM), near relay box. Turn ignition on. Measure voltage between ground and terminal No. 19 (Green/Orange wire) at PCM harness connector A-77. See Figure. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 4.
Check wiring between ignition switch and high speed radiator fan relay, and between high speed radiator fan relay and PCM. See appropriate ELECTRIC COOLING FANS article in ENGINE COOLING. If problem exists, repair wiring as necessary. If problem does not exist, replace high speed radiator fan relay.
Using a jumper wire, ground terminal No. 19 (Green/Orange wire) at PCM harness connector A-77. If radiator fan does not operate at high speed, go to next step. If radiator fan operates at high speed, go to step 6.
Check wiring between battery and high speed radiator fan relay, and between high speed radiator fan relay and radiator fan. Check radiator fan ground circuit. Check radiator fan. See appropriate ELECTRIC COOLING FANS article in ENGINE COOLING. If problem exists, repair wiring or replace radiator fan as necessary. If problem does not exist, replace high speed radiator fan relay.
Inspect PCM connectors for damaged wires or terminals. If problem does not exist, go to next step. If problem exists, repair connector(s) as necessary.
Turn ignition off. Connect all disconnected components. Using scan tool, retrieve and record DTCs and freeze frame data. Clear DTCs. Test drive vehicle under conditions when DTC was set. If DTC returns, replace PCM. If DTC does not return, test is complete.