Cooling Fan High Speed Circuit

WARNING: This page is about a different car, the 2002 Nissan Maxima and 2002 Infiniti I35. However, it is still accessible from the selected car via links, so may be relevant.

Turn ignition off. Disconnect cooling fan relays No. 2 and 3. Turn ignition on. Measure voltage between ground and cooling fan relays No. 2 and 3 harness connectors terminals No. 1 (Brown wires) and No. 3 (Green wire on cooling fan relay No. 2; Blue/White wire on cooling fan relay No. 3). See Figure . If battery voltage exists, go to step 3 . If battery voltage does not exist, go to next step.
Check the following:
- Check Gray, 6-pin joint connector No. 8 (connector E19). See Figure . Connector E19 is located in fuse and fusible link box on left side of engine compartment. See Figure or Figure .
- Check White, 6-pin joint connector No. 9 (connector E20). See Figure . Connector E19 is located in fuse and fusible link box on left side of engine compartment. See Figure or Figure .
- Check for open or short between joint connectors and cooling fan relays.
Repair as necessary.
Turn ignition off. Disconnect both cooling fan motor harness connectors. See Figure . Check continuity of the following:
- Red/Yellow wire between cooling fan relay No. 2 harness connector terminal No. 5 and cooling fan motor No. 1 harness connector terminal No. 1.
- Blue/Black wire between Cooling fan relay No. 2 terminal No. 7 and cooling fan motor No. 1 harness connector terminal No. 4.
- Black wire between cooling fan relay No. 2 harness connector terminal No. 6 and body ground.
- Red/Black wire between cooling fan relay No. 3 harness connector terminal No. 5 and cooling fan motor No. 2 harness connector terminal No. 1.
- Blue/Red wire between cooling fan relay No. 3 harness connector terminal No. 7 and cooling fan motor No. 2 harness connector terminal No. 4.
- Black wire between cooling fan relay No. 3 harness connector terminal No. 6 and body ground.
Also, check circuits for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
Disconnect ECM harness connector. See Figure . Check continuity of Light Green wires between cooling fan relay No. 2 harness connector terminal No. 2, cooling fan relay No. 3 harness connector terminal No. 2 and ECM harness connector terminal No. 36. See Figure . Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If problem is not found, go to step 6 .
Check the following:
- Check for poor connection at Gray, 8-pin connector F17 terminal No. 7 (Light Green wire). See Figure . Connector F17 is located on left side of engine compartment. See Figure or Figure .
- Check White, 6-pin joint connector No. 10 (connector E21). See Figure . Connector E21 is located in fuse and fusible link box on left side of engine compartment. See Figure or Figure .
- Check for open or short between ECM and cooling fan relays No. 2 and 3.
Repair as necessary.
Using jumper wires, apply battery voltage between removed cooling fan relay terminals No. 1 and 2. See Figure . Check continuity between terminals No. 3 and 5. Also check continuity between terminals No. 6 and 7. Continuity should exist. Remove jumper wires. Continuity should not exist. If continuity is as specified, go to next step. If continuity is not as specified, replace cooling fan relay and retest system.
Using jumper wires, apply battery voltage to cooling fan motors as shown in illustration. See Figure . If cooling fan motors operate as specified, go to next step. If cooling fan motors do not operate as specified, replace faulty cooling fan motor.
No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.