2002 Maxima SE, 110,000 miles.

I have a U1000 DTC code (usually followed by U1001, U1000) that I am struggling with.

I’ve located the ECM-F48, TCM-F51, F55 to M162, and the M15 to E81 SMJ connectors. I've cleaned them with electrical contact cleaner. I've cleaned and tightened the F39, F40, F41, and F42 ground connections to the engine.

While doing this I noticed that the F55 to M162 connector (below the radio area on driver’s side) had white tape around it. I also have some evidence, although it may be a coincidence that moving this connector around causes the U1000 error to go away for a while. After moving this connector I was able to drive 100 miles, and then sit for two days, then around 75 miles back (all with no errors) before getting the U1000 back. But this time with various O2 type errors. It was in this mode for a few a weeks where I can drive one or two small trips then I get U1000, U1001, and U1000 along with some combination of P0031, P0138, P152, P0158, P0132.

Currently I am getting U1000, U1001, U1000, and P132 pretty consistently.

I also notice that when I turn the ignition on, the AT light flashes 16 times and when I try to use cruise control the "Set" light flashes. At least once I notoiced that the crusie control worked when I had no check engine light errors, but I think I've seen the cruise set light flashing with no DTC errors.)

I assume I should ignore the AT light flashing, curise control Set light flashing, and all other DTC errors (ie P0031, P0138, P152, P0158, P0132) when acompanied with a U1000 error. Or can the P0132 error, for example, be a clue of as to why I have the U1000 error? I always have either no errors, or only U1000 errors, or U1000 and O2 type errors.

If the CAN communications (wiring and grounding) is solved, can I expect there to be no U1000 errors imeadiatly on my OBDII reader. For example, driving 175 miles with no errors then getting a U1000 along with an O2 error; Is it possible that the O2 error is real and the U1000 is from memory? (I'm assuming that if there is no DTC errors, then I get a U1000 code, that the CAN communication is bad. Period.)

I'm tempted to splice the two can wires at the ECM and TCM and jumpering them directly (from ECM to TCM) to bypass any possible intermittent connection in the factory harnesses. (I'm at wits end.) (Or alternately jumpering the CAN wires around the suspect F55 to M162 connector.)

Any advice would be appreciated.

I have an OINNOVA ODBII reader.

History: Last year I had a check engine light errors P0445 and P1448 and ended up paying $1000 to a local shop who replaced the cut valve, evap canister, gas cap, etc. It only stayed off a few months and now I have this new U1000 error. (I'm suspicious that they caused the U1000 in some way (loose wire or ground connection not tight? Possibly involving that white tape?)

 

Any resolution for you? I'm having the same codes w/ my 02 Altima?

 

No. After getting it fixed to the point that I can get my sticker, I gave up on getting it fully fixed.