Fuel Injector Circuits (Pathfinder & QX4)

Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
Start engine. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. Each cylinder should drop off when tested. If engine performs as specified, go to step 10. If engine does not perform as specified, go to step 4.
Start engine and listen to each fuel injector. If every injector clicks, go to step 10. If any injector does not click, go to next step
Turn ignition off. Disconnect suspect fuel injector 2-pin harness connector. Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 1 (Red wire). See WIRING DIAGRAMS article. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
Check following:
- Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F22 and M33. See WIRING DIAGRAMS article.
- Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F5 and F100.
- Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M10.
- Check fuse block fuse No. 21 (10-amp).
- Check for open or short between suspect fuel injector and fuse.
If problem is found, repair as necessary. After repair, retest system.

Turn ignition off. Disconnect ECM 116-pin harness connector. See Figure. Check continuity between fuel injector harness connector terminal No. 2 and specified ECM harness connector terminal. See FUEL INJECTOR CIRCUIT IDENTIFICATION (PATHFINDER & QX4) table. See Figure. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 9.

FUEL INJECTOR CIRCUIT IDENTIFICATION (PATHFINDER & QX4)

Injector No.	ECM Terminal No.	Wire Color
1	101	Red/Black
2	103	Red/White
3	105	Red/Yellow
4	107	Red/Blue
5	102	Blue/White
6	104	Purple/Red

Check following:
- Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F5 and F100. See WIRING DIAGRAMS article.
- Check for open or short between in-line harness connector F5 and ECM.
- Check for open or short between in-line harness connector F100 and suspect fuel injector.
If problem is found, repair as necessary. After repair, retest system.

NOTE: Removal of intake manifold collector maybe required to perform this step. See FUEL RAILS & INJECTORS under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION article.

Disconnect 8-pin in-line harness connector F100. In-line harness connector is located along leftside of intake manifold. Disconnect all fuel injector 2-pin harness connectors. Check continuity between all fuel injector harness connector terminal No. 2 and specified in-line harness connector F100 terminals. See CHECKING FUEL INJECTOR SUB-HARNESS CONNECTOR (PATHFINDER & QX4) table. See Figure. Continuity should exist. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.

CHECKING FUEL INJECTOR SUB-HARNESS CONNECTOR (PATHFINDER & QX4)

Sub-Harness Connector Terminal No.	Wire Color	Fuel Injector No.
1	Blue/White	5
2	Red/Yellow	3
3	Red/Blue	4
4	Red/White	2
5	Red	Power Supply
6	Red/Black	1
7	Purple/Red	6

Check fuel injector. See FUEL INJECTOR . If problem is found, replace as necessary. If no problem is indicated at this time, go to next step.
No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.