MiniTorque.com banner
1 - 18 of 18 Posts

·
Registered
Joined
·
202 Posts
Discussion Starter · #1 ·
Started yesterday with the head unit output dying off. Then I lost all instrument lighting, indicators working but no relay clicking, no a/c light on. I figured the BCU is borked & took it off this morning. No corrosion, water ingress or broken pins. Now the car cranks but won't start. Scan give P0122/3 & 18 I.e. throttle input high, low & temperature data sporadic.

Too many issues all at once on a car running perfectly 24 hours ago. All submissions welcome.
 

·
Registered
Joined
·
202 Posts
Discussion Starter · #6 ·
Been round most of the easy earth points. I'm almost certain something's up in the K bus. All the failures, radio, multi function wheel, a/c etc. depend on it. Next stop, cluster out, start testing wires. I had this three years ago, almost identical symptoms but it spontaneously returned to normal & I didn't pursue it.
 

·
Registered
Joined
·
1,534 Posts
Start with basics which are easy to rule out.

Battery can cause all sorts of seemingly random electrical gremlins, hence my saying that yesterday.

I am not saying it is, but it could be.

It takes no time to plug it in overnight & see what happens in the morning.
 

·
Registered
Joined
·
1,102 Posts
I know this might sound very basic/fundamental:

Check the leads are connected to the battery terminal properly. You need to check the 10mm bolts are fully done up. It is possible for them to look connected but not be tight enough.

I would also check that the ECU plugs (in the compartment next to the air filter box) are fully seated. Another simple check.
 

·
Registered
Joined
·
202 Posts
Discussion Starter · #12 ·
Good advice thanks Nigel. I've been through all the bay wiring & had the dash & sill panels off both sides this morning. The upshot is all ground points are good, no water ingress anywhere, no fuses gone, no obvious wiring damage It's pointing at the battery or the BCM now. I don't have a spare BCM. Scans are throwing multiple codes which now clear ok. Next stop, try to get hold of a charger & top up the battery.
 

·
Registered
Joined
·
202 Posts
Discussion Starter · #13 ·
Update on this, I got hold of a charger, topped up the battery overnight. It's giving 12.8 volts, the car now starts normally, no engine codes. I still have no radio, demisters or aircon. Scan shows K bus fault, no message on Kom2, so still some fault finding to do but at least I can drive it around. Small victories.
 
1 - 18 of 18 Posts
Top