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my 1997 Infiniti J30 had the engine die at a stoplight. It turns over when I try to start it, but the engine won't start. The power windows were partly down, and they now won't go up, although the radio, turn signals and headlights seem to work fine. I tried using the diagnostic mode switch to reset the ECM but no it made no difference so far. Jumping it does nothing because the battery seems fine. I checked the fuses for the starter and related things, and they all look fine. None of the relays under the hood seem melted or bad. My OBD scanner just says "error" when I try it. I took it to a mechanic and he claimed I have to update the ECM software for him to diagnose it, and the dealers want $130 to do that. I can't find a replacement ECM for under about $170. Any ideas what could be wrong or how to fix it? Thanks in advance.

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    "have to update the ECM software for him to diagnose it," horse hockey – Moab Aug 4 '16 at 3:08
  • That was my thought as well, since I used a standard OBD reader on it when it had previous problems and that worked at the time. Sounds like I need a new ECM? – user3573647 Aug 4 '16 at 4:54
  • does the check engine light come on, key on engine off? – Ben Aug 4 '16 at 13:47
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    do you have a service manual for the car? i doubt the ecm would just fail like that. i'd suspect that the wiring to the ecm is bad in some way e.g. a bad ground or power wire/fuse. – Ben Aug 4 '16 at 23:27
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    The same user has the same "ERROR" on the scantool on a completely different vehicle ('97 Ford Ranger). Just an observation. – SteveRacer Aug 21 '16 at 21:27
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It sounds like you have a few things going on.

  • If your OBD scanner reports "error", it's that your ECU isn't responding. Maybe your ECU isn't getting power, maybe it's defective.
  • Your power windows being stuck suggest an overall electrical glitch in the car. Since the car is almost 20 years old, check to see that there isn't a switch (power window, power lock, etc) that isn't "stuck" and hasn't returned to center (I've seen this in a 96 Intrepid).
  • Get your battery tested, make sure it's good.
  • Clean your battery terminals.
  • Inspect all electrical connections, especially to the ECU.
  • Inspect your engine ground. They get corroded easily.
  • For a replacement ECU, junkyard is always cheapest option. It will allow you to rule out your ECU being defective.
  • Inspect all fuses closely.
  • I will try your suggestions, thanks. I'm pretty sure it's the ECM at this point, as the odds of several problems manifesting at once are less likely. But always a good idea to try the easy fixes first. – user3573647 Aug 4 '16 at 4:56
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    Second the suggestion to inspect and clean the ECU connections. It could be the gasket failed and moisture has gotten in to the ECU or its connectors. A quick squirt of contact cleaner could be all you need. – TMN Aug 4 '16 at 12:44

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