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Fuel Injector Circuits (Frontier V6 & Quest)

  1. Start engine. If engine does not start, go to next step. If engine starts, listen to each injector. If every injector clicks, system is okay. If any injector does not click, go to next step.
  2. Turn ignition off. Disconnect inoperative injector harness connector. Turn ignition on. Measure voltage between ground and appropriate injector harness connector Black/Red wire (on Frontier V6), or Yellow wire (on Quest). If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See appropriate diagram in WIRING DIAGRAMS article.
  3. Turn ignition off. Disconnect PCM harness connector. See Figure or Figure . Check continuity of specified wire between PCM harness connector and appropriate injector harness connector. See FUEL INJECTOR CIRCUIT IDENTIFICATION (FRONTIER V6)  or FUEL INJECTOR CIRCUIT IDENTIFICATION (QUEST)  table. If continuity exists, go to next step. If continuity does not exist, repair open in appropriate wire.
  4. Check fuel injector. See FUEL INJECTOR . Replace, if necessary. If injector is okay, no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
FUEL INJECTOR CIRCUIT IDENTIFICATION (FRONTIER V6)

Injector No. PCM Terminal No. (1) Wire Color
1 102 White/Black
2 109 White/Blue
3 104 White/Red
4 111 White/Purple
5 106 White/Green
6 113 White
(1) See Figure.
FUEL INJECTOR CIRCUIT IDENTIFICATION (QUEST)

Injector No. PCM Terminal No. (1) Wire Color
1 102 Green/Orange
2 109 Green
3 104 Green/Red
4 111 Yellow/Purple
5 106 Yellow/Green
6 113 Gray/Blue
(1) See Figure.