Electrical fault or ECM fault?

2014 HOLDEN CAPTIVA

257,000 MILES • 2.4L • MANUAL

BEAU43

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I have warning lights on the dash as follows: ABS - Traction control - Stability control - Lightning Bolt with Spanner - Fuel info says “F”kms to empty - no speedo or tacho - wipers came on randomly & wouldn’t turn off - engine wouldn’t turn off with key, turn key off & remove it from ignition but engine still run so put key back in & took a few goes to turn off, Lights on dash will come on while driving & sometimes go off & sometimes stay on & sometimes not just very random, Car doesn’t handle the best when lights are on, can I still drive this???
Recently (3-4wks ago) replaced Camshaft Position Sensor - Camshaft Position Actuators - Oil & Filter - Spark Plugs - Pre CAT O2 Sensor…
Issues only just started to happen today, can’t see a blown fuse, battery light is green & 13V engine Off - 14.9V at idle.
Any ideas on what to do & where to start & should I drive it (it’s my only form of transport).

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May 19, 2026 at 11:24 AM

STRAILER

CAR REPAIR CONTRIBUTOR
54,354 POSTS

This does not sound like a single bad ECM first. It sounds much more like a system voltage / ground / CAN communication / BCM-power problem affecting multiple modules at once. Did you remove any grounds when you were doing the repairs? If so please recheck the work. Next, with the systems on lets check the fuses, this guide and video will help.

https://www.2carpros.com/articles/how-to-check-a-car-fuse/

and

https://www.youtube.com/watch?v=G-xNK79Wa-w

My bet is a bad ground which will affect all of these systems. Please let me know what happens.

May 20, 2026 at 4:00 PM

BEAU43

MEMBER
3 POSTS

Cheers for ur reply STRAILER, I took the fuse box apart to check for condensation & rush underneath, it was fine. Checked my main Ground wires, they’re all fine.
It started to make a buzzing noise from fuse box under bonnet then same noise from fuse box under dash in car & only way I could stop the noise was to disconnect the earth from battery. Is there a way to test relays? A mate said it could be a faulty wiper motor because the sounds also coming from near there as well. It’s got me buggered I think so might need to get an auto elec out to have a look it’s just guna cost a fortune because auto elec aren’t cheap these days

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May 28, 2026 at 8:21 AM

STRAILER

CAR REPAIR CONTRIBUTOR
54,354 POSTS

Hmm, that is a good one, I am wondering if the battery voltage is good, you might have a bad battery please go over this guide to help you see, or take the battery out and have it tested at the auto part store. Thanks for the video it helps.

https://www.2carpros.com/articles/car-battery-load-test/

Please go over this guide and get back to me.

May 28, 2026 at 4:38 PM

BEAU43

MEMBER
3 POSTS

I’m thinking it might be the wiper motor, the buzzing noise is coming from the wiper motor as well & can feel it vibrating so I removed the Wiper Speed Relay & Wiper Control Relay from under the bonnet & then the noise started at the fuse box inside the car so I removed the Main Relay & noise stopped. This relay was pretty warm & definately buzzing like crazy (the cover came off the relay I could hardly touch it to remove without its cover as it was hot & felt like a tattoo gun kind of vibration. I’ll go get some new relays tomorrow & price a wiper motor) so I’ve left the ground connection off of the battery overnight to reset computers as well. i’ll keep ya updated

May 28, 2026 at 5:24 PM

STRAILER

CAR REPAIR CONTRIBUTOR
54,354 POSTS

The electrical can act that way if the battery voltage is low fyi. Also, I would check the ground from the battery to the engine and then chassis, both must be good.

May 28, 2026 at 9:43 PM

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