Z32 ECU power issue/Anti Theft question

Discussion in 'Technical' started by ZcrazyZx, Jun 11, 2019.

  1. ZcrazyZx

    ZcrazyZx New Member

    Dash and accessories work fine, fuel pump primes on ignition and the car cranks over well but wont start.
    The car died on me while driving a few months back and wouldnt start again, since then i've swapped in a new engine as the old one was almost dead, i tucked the fuse boxes, loom and PTU to the ECU area aswell. All went well and everything was done properly, only around 12 wires were cut and joined (Front Headlights, indicators and the Oil pressure sensor)
    Now i was checking the ECU power supply as per FSM, only one of the 12v power wires carried 12v and the rest had 0. The ECU still turns on with IGN and gives code 55 but wont power to the injectors or coils. I've redone every ground and double checked them with a multimeter, every fuse has been checked and the fusible links are fine, i replaced the battery ground harness and alternator harness to top it off. The previous owner had an AVS alarm system installed and i think it might be the cause, the car would only start when it was in a locked state, and to turn it off i had to remove the key, lock it then back to IGN and it would stop. Can an alarm alone prevent the ECU from receiving the power it needs? Any help is much appreciated, cheers :)
  2. zx299

    zx299 Well-Known Member

    It sounds like you've created a wiring issue because the 3 power wires for the ecu are all controlled by the same relay
  3. ZcrazyZx

    ZcrazyZx New Member

    I'll have to do some more testing and make sure thank you. Seems to be the exact trouble i had a few months back when it died on me so im pretty sure its an underlying problem, every plug i de-pinned has been checked at least 3 times and compared with my other Z, theres no voltage drop on the battery to signal a short either. I'm in the process of removing this alarm system and whoever installed it made a mess of the ignition wiring :eek: It ties into every wire coming from the ignition and i found 2 wires spliced at the ECU plug, one appears to be joined to the speed sensor wire and the others connected to one of the ECU's power supplies. Both with budget snap on connectors :confused: That'll explain my intermittent speedo and fingers crossed solve the starting problem, will get back to you soon on how it goes. Thanks for the help man
  4. Martin Williams

    Martin Williams Well-Known Member

    Is you ignition relay energising? Lefthand side engine bay? you say you worked on this fusebox, perhaps you disturbed something

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