Home/Infiniti/Q45/Infiniti Q45 II (1996-2001)/Repair manual/Testing & Diagnostics/Engine Controls - System/component Tests: Diagnosis
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Engine Controls - System/component Tests: Diagnosis Infiniti Q45 II

SYSTEM TEST

Start engine, and warm to operating temperature. Check idle speed. If idle speed is excessive, disconnect IAC valve harness connector. Idle speed should drop. If idle speed does not drop, check IAC valve and related circuits. See DTC P0505: IDLE AIR CONTROL (IAC) in appropriate TESTS W/CODES articles below.

  1. For I30 see «TESTS W/CODES»(ref-18055)
  2. For Q45 see «TESTS W/CODES»(ref-18056)

START SIGNAL SYSTEM TEST

  1. Turn ignition switch to START position. Measure voltage between ground and appropriate PCM harness connector terminal. See «START CIRCUIT WIRE COLOR & PCM TERMINAL IDENTIFICATION»(ref-18057-S22288551552000122900000) table for wire color. (Схема №1) Battery voltage should be present in START position only. Zero volts should be present in any other ignition switch position.
  2. If voltage is not as specified, check fuse No. 33 (7.5 amp) on I30, fuse No. 34 (15-amp) on Q45, in fuse box. If fuse is okay, repair circuit between PCM and fuse box. If voltage is as specified, check PCM terminals, harness, and harness connector terminals for damage or corrosion. Repair as necessary.
ApplicationPCM Terminal No. (Wire Color)
I3020 (Brown/White)
Q4580 (Light Blue)

START CIRCUIT WIRE COLOR & PCM TERMINAL IDENTIFICATION