Applied vehicles:
2004 Maxima (A34)
2004 Quest (V42)
2004-’05 Altima (L31) with VQ35 only
Concern:
An MIL “On” with one or more of the following DTCs stored:
• P0300, P0301, P0302, P0303, P0304, P0305, P0306 (cylinder misfire); or
• P1273, P1283 (A/F ratio lean).
Action:
Injector resistance may cause one or more of the above listed DTCs to be set.
• Check the resistance of the injectors against the values in this bulletin.
Note: Incident injectors will have resistance values:
– outside of the specified range indicated in
this bulletin and
– will be significantly different from the non-incident injectors at the other cylinders.
Important: The purpose of the Action is to give you a quick idea of the work you will be performing. You must closely follow the entire Service Procedure as it contains information that is essential to successfully completing this repair.
Service Procedure:
Use Chart 1 to determine which injectors to inspect.
DTC 1273 = Bank 1 (requires checking only that bank)
1. Locate and separate the F44 engine harness connector from the F101 injector sub-harness connector. See Fig. 1. 
2. Using Chart 1 and the pin location in Fig. 2, measure the resistance of the injector(s).
DTC 1283 = Bank 2 (requires checking only that bank)
Important:
• Replace an injector only if its resistance is outside of the above range and the resistance is much different from the resistance of the other injectors.
– A single injector usually causes this incident. If more than one injector has resistance values out of specification:
– there might be a general problem with the accuracy of the resistance measurement, or
– component (injector) temperature condition may be high or low, or
– the vehicle is not of the applicable range.
DTC P0301-P0306 requires checking a single injector.
(refer to Chart 1 and the procedures used in DTC P1273 or P1283)
DTC P0300 (requires checking all injectors)
(refer to Chart 1 and the procedures used in DTC P1273 and P1283).
Note: It’s possible that a single injector incident:
– can affect the air/fuel sensor control for a bank of cylinders, and
– this can result in a P0300 code.
If the resistance of all the injectors is within 11.5 to 15.5 Ohms at 50-190° F (10-88° C), and the engine temperature is in the room temperature to engine warm temperature range, return to ASIST for further diagnosis.
Courtesy of Mitchell 1.
