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VZ ECU self-resetting

PilgrimRunner

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Greetings all,

So after coming back to my car after 5 weeks, it came up with the dreaded low fuel warning followed by a service warning followed by a faulty gauge warning.

After some fiddling, I bypassed the start relay and she started just fine. After a while.all faults disappeared, and I turned the car off. I tried again after 15 minutes and we were back to the beginning.

I am assuming that the ECU is resetting for.some reason. Any ideas, before I go and purchase a new ECU?

Cheers in advance
 

Fu Manchu

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The one common denominator with this fault is having the car not used for a while. It seems to be specific to V6.
For us, it slowly went away.
My standing theory is a corroded contact in a relay or switch somewhere and low voltage combining to create a problem.

Many have the ECM replaced at great expense. Still doesn’t solve it.

A week or two ago I found a solution in a random YouTube video. I posted it as a thread. The ECM relay. Not only that but there are two relays that can fit. One is right and one isn’t.
 

Fu Manchu

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I should add that the relay had corroded/damaged contacts.
 

Fu Manchu

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864D1FAE-9567-4CF0-8F4C-1BB952DC75AD.jpeg

Engine Control Relay.
 

PilgrimRunner

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Thanks

I have exchanged the relays already...and it didn't seem to help

I will continue to look for other bad connections.
 

Fu Manchu

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Disconnect the battery negative.

(Clean terminals or earth points using some steel wool, or scotchbrite, or a small wire brush)

Clean the earth for the ECM.
The earth point below the ABS module.
Remove the positive terminal and then remove the battery by undoing to 13mm or 12mm bolt on the tray that clamps the battery in place.

Now you have access to the earth point for most of the harness. It’s on the guard. Retap the thread. Clean the thread with the scotchbrite and CO contact cleaner.
Clean out the plug, and the pins with an emery board.
Then take a look at the earths on the heads. Same deal. Clean the thread and clean off the bolts and the eyelet surface.
Clean the battery terminals and on the battery.
 

PilgrimRunner

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UNBELIEVABLE!!!

I cleaned all the earth terminals as you suggested. They looked ok before hand, but I made sure they were spotless before I reattached them.

...and it started first time!!! Thank you..I owe you a few beers!!
 
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