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Replaced both camshaft sensors and now the engine has a difficult time starting

(2004 Infiniti G35)
in West Des Moines, IA on August 22, 2009
I recently replaced my front brakes and rotors. I started to have problems starting my car. the check engine light came on saying that i had to replace my camshaft sensors. I replaced both of them. The car still has a difficult time starting.
Displaying 2 answers & 6 comments
Popular Answer
on August 22, 2009

Vehicle Application: 2002 Infiniti I35 3.5L 2003 Nissan Maxima 3.5L
2002 Nissan Maxima 3.5L

Customer Concern: Trouble code P0340.
Tests/Procedures: 1. Monitor the signal on the camshaft sensor with a lab scope. It should have a sine wave pattern and produce 3v. There is a TSB for an updated cam and crank sensor on this vehicle. NTB 03-124. It is possible to have a wire harness problem at the passenger strut tower that can cause this code. Make sure the camshaft timing is also correct.
Potential Causes: Camshaft Position Sensor (CMP)

Tech Tips: With the engine running, tug and twist the wiring harness, at the passenger strut tower, to see if there is a reaction.
Diagnostic Codes: P0340
on August 22, 2009
It would be much more helpful if you had a trouble code.
on August 24, 2009
Vehicle Application: 2004 Nissan Quest 3.5L 2005 Nissan Murano S 3.5L

Customer Concern: Check Engine Light is ON. Controller Area Network (CAN) communication code U1000.
Tests/Procedures: 1. Check freeze frame data to see what the engine parameters were when the code set, to see if engine coolant temperature and intake air temperature readings are -40 degrees and -58 degrees F, indicating a possible Engine Control Module (ECM) ground problem as indicated in TSB# NTB06-009.

2. If the freeze frame data does not indicate the above readings, the TSB does not apply. This is a very difficult code to diagnose without a factory Consult II scan tool, as information needs to be gathered from each of the control modules for each system connected to CAN. Then, using matrix charts in the factory service manual, see what systems apply to the vehicle being worked on, and then, using other charts in the factory service manual, see which matches the vehicle results, to determine the area of the malfunction.
Potential Causes: Defective ECM Ground Supply

Diagnostic Codes: U1000, U1001
on August 24, 2009
Vehicle Application: 2002 Infiniti I35 3.5L 2003 Infiniti I35 3.5L
2002 Nissan Altima 3.5L, Eng Cfg V6, Eng Des VQ35DE 2003 Nissan Maxima 3.5L
2002 Nissan Maxima 3.5L 2003 Nissan Pathfinder 3.5L
2002 Nissan Pathfinder 3.5L 2004 Nissan Pathfinder 3.5L
2003 Infiniti G35 3.5L

Customer Concern: Check Engine Light is on. Code P0021 - Intake Valve Timing (IVT) control for Bank 2 - radiator bank.
Tests/Procedures: 1. Check the engine oil level and condition. If the engine oil is low, it could set this code.

2. If the oil is good, check the IVT Control Solenoid voltage on the Red wire for battery voltage to the solenoid and the Green wire for the on/off signal when the engine is revved to 2000 RPM.

3. If the signal is good, then the ECM is trying to control the valve timing. Manually ground the Green wire for the IVT Control Solenoid to see if there is a change in the way the engine idles. If so, the solenoid is working. If not, the solenoid could be stuck.

4. The resistance of the IVT solenoids is 7.5 ohms at 70 degrees F.
Potential Causes: Intake Valve Timing Control Solenoid — Intake Valve Timing Control Solenoid for Bank 2.
Low Oil Level

Tech Tips: The Engine Control Module (ECM) sends on/off pulse signals to the Intake Valve Timing Control Solenoids to vary the intake valve timing depending on the driving status. The ECM monitors the intake camshaft positions to verify that the camshafts are where they are commanded to be.
Diagnostic Codes: P0021
on August 24, 2009
P1574 ASCD Vehicle Speed Sensor Signal MalfunctionPossible Causes Setting Conditions
CAN communication connector is damaged (check pins for damage, moisture)
CAN communication line is open, shorted to ground or shorted to voltage
Combination Meter VSS circuit is open or shorted to ground
Combination Meter has failed
Vehicle Speed sensor has failed
DTC P0500, P0605, U1000 and U1001 not set; engine running; vehicle speed over 25 mph, and the PCM detected a difference in the VSS signals from the Combination Meter and TCM. The status of the ASCD is displayed in the Combination Meter (Cruise or Set).

This code sets in 1 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)
on August 24, 2009
I went back to clear the check engine light and 3 codes came up p0021, p1574 and u1001. It seems as though you were right. It relates to a connection or short. any thoughts or something that you have found in your experience? Your answer was right on and I thank you very much. Funny thing is all this happened at the time I had my front brakes and rotors changed. Any correlation? We did tug on the harness while the engine was running and nothing appeared to happen.
on August 22, 2009
why the difficult time starting? is it related to the camshaft sensor issue. The tech said that the car computer had to adjust and it will get better. so far not the case.
on April 20, 2014
make sure u used oem sencor I have the same problem
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