NotAnotherLandRover
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- Posts
- 24
- Location
- UK
Apologies, this is a long one, bear with…
I’ve got ADHD and this means my brain sometimes neglects to do the most basic of things…. Like turning the ignition off and taking the keys out of the car overnight This inevitably caused a flat battery and despite a hard reset and battery recharge it won’t start.
We’ve got warning lights and messages all over the place.
Today we spent some time going over a few things.
It’s deffo not the battery, it may have been the low voltage that’s caused the problem, but that’s not the problem now.
When we’ve plugged into the diagnostics scanner we’re not getting any communication from the engine ECU at all. All the other modules on the car communicate fine but are obviously reporting codes that there’s no communication with the engine ECU as you would expect.
We’ve checked the voltage to the pins at the ECU and the earths are there, the supply battery voltage is fine, the feed from the ignition switch to the ECU is fine but the ECU is not supplying the earth to the engine control relay. Which is obviously the problem…
But is this caused by the ECU failing or is it that the immobiliser is stopping the ECU? When we key on the immobiliser light continues to flash. It may be flashing because the ECU isn’t switching the relay.
Even if we bridge the relay - we still get no communication from the engine ECU. Perhaps pointing back to the ECU again.
Does anyone know how the immobiliser operates and where is it? Is it in the ECU, the instrument cluster or the BCM?
Side note, also noticed the water temperature gauge is off the scale (guessing this is because there’s no communication) and the other thing that’s strange is that with the ignition on you can move the gear selector freely without pressing the brake pedal.
I’ll take any wisdom right now thank you x
I’ve got ADHD and this means my brain sometimes neglects to do the most basic of things…. Like turning the ignition off and taking the keys out of the car overnight This inevitably caused a flat battery and despite a hard reset and battery recharge it won’t start.
We’ve got warning lights and messages all over the place.
Today we spent some time going over a few things.
It’s deffo not the battery, it may have been the low voltage that’s caused the problem, but that’s not the problem now.
When we’ve plugged into the diagnostics scanner we’re not getting any communication from the engine ECU at all. All the other modules on the car communicate fine but are obviously reporting codes that there’s no communication with the engine ECU as you would expect.
We’ve checked the voltage to the pins at the ECU and the earths are there, the supply battery voltage is fine, the feed from the ignition switch to the ECU is fine but the ECU is not supplying the earth to the engine control relay. Which is obviously the problem…
But is this caused by the ECU failing or is it that the immobiliser is stopping the ECU? When we key on the immobiliser light continues to flash. It may be flashing because the ECU isn’t switching the relay.
Even if we bridge the relay - we still get no communication from the engine ECU. Perhaps pointing back to the ECU again.
Does anyone know how the immobiliser operates and where is it? Is it in the ECU, the instrument cluster or the BCM?
Side note, also noticed the water temperature gauge is off the scale (guessing this is because there’s no communication) and the other thing that’s strange is that with the ignition on you can move the gear selector freely without pressing the brake pedal.
I’ll take any wisdom right now thank you x