1994 Infiniti Q45 BaseFACTORY OEM SERVICE PROCEDURE

Trouble Code Definition

NOTE: When DTC tests indicate to check a component, see indicated component in I - SYS/COMP TESTS article. For Diagnostic Trouble Code (DTC) illustration symbol identification, see Fig 1 . To identify ECM connector terminals, see WIRING DIAGRAMS article.
TROUBLE CODE IDENTIFICATION

Code System Affected Probable Cause
11 (1) Camshaft/Crankshaft Position Sensor (2) No Crank Signal
12  Mass Airflow Sensor Circuit Open/Shorted Circuit
13  Engine Coolant Temperature Sensor Open/Shorted Circuit
14  Vehicle Speed Sensor (VSS) No VSS Signal
16 (1) Traction Control System (3) Open/Shorted Circuit
21 (1) Ignition Signal Circuit (2) Open/Shorted Circuit
31  ECM Signals Not Normal
32 (4) EGR Function No EGR Operation
33  HO2S Sensor (Left) Open/Shorted Circuit/High HO2S Signal
34 (1) Knock Sensor Open/Shorted Circuit
35 (4) EGR Temperature Sensor Open/Shorted Circuit
43  Throttle Position Sensor Open/Shorted Circuit
45 (4) Injector Leak Leak At Injectors
46 (1) (With TCS) Secondary Throttle Position Sensor Open/Shorted Circuit
51 (4) Injector Circuit Injector Does Not Work
53  HO2S Sensor (Right) Open/Shorted Circuit/High HO2S Signal
54  54 (5) Automatic Transmission (A/T) Control Signal Open Signal Transmission Control Unit
55 (1) No Malfunction Light (MIL). Normal Condition
(1) Trouble code will not activate Malfunction Indicator Light (MIL).
(2) If Codes 11 and 21 are present at same time, check items causing a malfunction of camshaft/crankshaft position sensor circuit first.
(3) See ANTI-LOCK BRAKE SYSTEM article in BRAKE section.
(4) California models.
(5) Models with automatic transmission, Serial No. 450021 and later.
Fig 1: Identifying DTC Illustration Symbols
G90F18734Courtesy of NISSAN MOTOR CO., U.S.A.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.