# how do I remove computer on 2003 sentra



## bhawk (Jan 2, 2012)

2003 sentra with 1.8. My instrument cluster has been acting up lately. Basically all gauges such as speedo, tach, fuel, oil, temp, etc. drop to zero for a few seconds then come back on, or a few minutes, then come back on.
It threw a code U1001 when they went out for about a minute. The service manual says this code is set because "ECM can not communicate to other control units", with possible cause being "harness or connectors (Can communication line is open or shorted)".
Given the above DTC, I think I should pull the connectors off the computer and check them out for corrosion, etc. While I'm doing that, maybe I should pull out the computer and check the insulation. I read somewhere the insulation can give off sulpher fumes and damage the computer itself. 
Any tips or tricks in how to get the computer out?
Anything to beware?
Of course, I'll take the battery cables off before I do this.
Should I spray the connector tips, male and female, with electrical contact cleaner? Or, should I put a drop of dielectric grease on every male contactor?


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## smj999smj (Jan 1, 2006)

You can do all that, but there's a likely chance you have a bad instrument cluster. CAN Comm issues are tough to diagnose unless you have a scantool to access all the systems of the car and an FSM. ECM is located in the engine compartment on the passenger side cowl. Unplug the battery, remove the electical harness connectors and unbolt; slide the ECM out to remove. Grounding issues are also common caused for CAN Comm codes.


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## bhawk (Jan 2, 2012)

thanks for the advice. One bit of new info, for what it's worth, is that I also got a code P1574 (vehicle speed sensor) and code P0463 (fuel level sensor circuit high) at the same time as the U1001. When I looked these 2 codes up in the service manual, they say when they accompany a code U1001, this code relating to Can communication must be repaired first. So, that's why I'm going right to the computer connections.


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## smj999smj (Jan 1, 2006)

That makes it sound even more like a bad instrument cluster!


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## bhawk (Jan 2, 2012)

How do I remove the instrument cluster? Is the procedure described in the online service manual? thanks for your help.


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