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-   -   93 civic not starting, could not retrieve error codes. How to test the ECU ? (https://www.askmehelpdesk.com/showthread.php?t=190313)

  • Mar 2, 2008, 03:42 PM
    Mr_am
    93 civic not starting, could not retrieve error codes. How to test the ECU ?
    Hello,

    I have a starting problem with my civic 93 (4-door). Symptoms : good cranking , no spark and ECL goes away after 2 seconds as usual. It happened when I started it for 5 minutes and when I was trying to move... it stopped suddenly.
    - I checked the main relay.. re soldered its pins (did not help)
    - I replaces the spark plus wires and the distributor cap (did not help)
    - I checked all fuses (all were fine).
    - Could not retrieve the error codes using the 1-pair connector and a jumper wire and the ECL stayed on all the time.
    - I replaced the coil (did not help). No spark.
    - I checked the MAP sensor for 5 V... gives 4 V.
    - I replaced the igniter. It started fine.. I tried only once, stayed for 5 minutes.. I turned it off and left it till next day. The following day I fixed the main relay in its place and tightened the distributor cap.. not starting at all. (all parts ought are the original ones from Honda).
    - I checked the battery cables, cleaned them (did not help).
    - I took off the ECU, opened it and its looks fine and I put it back.. same thing. It seems that the ECU is not giving the signal to the igniter.
    - I tried to retrieve the error codes... same result.. the ECL stayed on. I recharged the battery few times already to make sure it is fine.. cranking is fine.. seems no spark.


    What is wrong ? How to troubleshoot the ECU ?
  • Mar 2, 2008, 05:23 PM
    TxGreaseMonkey
    . Clean main ECM ground, located on the thermostat housing.

    . Clean MAP Sensor connector of any oxidation.

    . Perform K-Test at various times. ECM is likely bad, if reference voltage is less than 5 volts.
  • Mar 3, 2008, 03:25 PM
    Mr_am
    Well, I have done some checks this afternoon... and all was fine... I thought again about the distributor... and said may be there is something wrong there... and I started checking wires.. Guess what ? I have found the negative terminal of the coil loose.. I think I have installed it when it was very cold outside and was difficult to work efficiently.. besides the two little screws heads of the coil were worn out... so I tightened them.. and there it is.. it starts easily. I admit that my car has never started well before (may be needed some tuning).

    Thank you very much... your advice was a great help.

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