QuestionThank you, Von.
Can ECM be unplugged easily by myself? Any easy way to reset the light myself? (without scanner).. Any trick?
What are your comments on O2 sensor work? was it necessary? Or I senselessly spent 550 bucks..
Thanks
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Followup To
Question -
Hi Von,
Since couple months I am struggling to correct "Service Engine Soon" problem with my Nissan Sentra GXE 2000. I am located in IL. Since 6 months or so, the SES light was ON. Emission Test requires OBD II clearance, therefore I had to visit the local mechanic to correct the problem. He diagnosed it as P0171 (system too lean bank#1) code. I ended up changing one O2 sensor out of 4, the code still came back after a few miles drive. I ended up changing another O2 sensor for the same pair. Again light came up. Did fuel injection system cleaning too, no luck. I even consulted another mechanic too for 2nd opinion. Now, the mechanic is telling me, i have to change the ECM board (the voltage is significantly low (0.06 or so as I recall) and so scanner shows a lot of fluctuation). So, I am thinking about it and asking for your advice whether that's the real cause & solution? Since couple days, I've noticed lack of power too. I had to heat up the car for 5 min. thenonly, it drives OK. Still I feel little lack of power with a stop-n-go driving.
Any suggestions? I am little desperate now, the EmissionTest has to be cleared this month, otherwise they may suspend my license.
Will ECM replacement fix the problem permanently?
Thanks very much in advance.
KD
Answer -
KD,
The ECM should not be replaced until you check to see if the connection to the ECM is good. Basically, unplug the ECM and plug it back it and reset the light. If the light stays off it was a bad connection. This is common. If not replace the ECM...
AnswerKD,
The ECM has a lever that releases the connector and there is a small bolt/screw that has to be undone to get at the lever and it just comes off when you lift the lever out. That way the connector comes out evenly and goes back the same way. The oxygen sensors do fail and at about 50K miles is common. I have seen some go for ten years and I have seen some contaminated in just two or three years. So, the oxygen sensors could very well have been bad. This is especially true if you get some bad gas. The code should clear if you disconnect the battery for five minutes. Now, if you do the harness thing disconnect the battery first and when it is reconnected the code should be gone when you hook the battery back up. If not then it is the ECM.
