ABS lights x 3, no fault, no clue. @ wit's end...

**annette** · 2017/04/12, 06:21 AM

Sorry to bother you with what seems a very common problem.

Client's 2008 Puma has had various problems which we could sort but I can't get to the bottom of this.

Hawkeye Pro finds NO faults, sometimes a bad ground. Once or twice it told me it had a ¿¿¿¿ throttle position problem

? Have quitted the error 245 times. Made a better earth for the ECU including the black wire leading to the violet plug C0506 nº3 . Ground error didn't come back since, only sometimes as historical.

checked ground on bulkhead, is fine.

Checked every single valve and connector and fuse and relay.

Checked sensor operation.
getting 2,27V on the left one, 2.28V on the right, resistance 1.42 kΩ on both.
When turning the wheels or driving sloooowly ,before diagnoistics goes on strike, I am getting 1.8-3.5 on the left one, a steadier value from 2.1 to about 3V on the right one.

Robbed a sensor from a td5, was the same as the left one. Used it also in the other spot.
No difference.

Tried my brand spanking new Gap IID tool on it, doesn't even talk to my ABS problem. It did before I upgraded it though.

The only time these

lights went off was when my partner was spraying lots of diesel around to clean something. We have strong winds at the moment so the diesel went all the way to Australia and must have taken the lights by surprise. Never mind, they came back after 10 kms.

Result was that I had to give the car back today with a persisting problem.
Any ideas welcome. If it makes me look like an idiot, fine. I just have to fix it.

**JuanB** · 2017/04/12, 06:47 AM

Originally Posted by annette

Sorry to bother you with what seems a very common problem.

Client's 2008 Puma has had various problems which we could sort but I can't get to the bottom of this.

Hawkeye Pro finds NO faults, sometimes a bad ground. Once or twice it told me it had a ¿¿¿¿ throttle position problem

? Have quitted the error 245 times. Made a better earth for the ECU including the black wire leading to the violet plug C0506 nº3 . Ground error didn't come back since, only sometimes as historical.

checked ground on bulkhead, is fine.

Checked every single valve and connector and fuse and relay.

Checked sensor operation.
getting 2,27V on the left one, 2.28V on the right, resistance 1.42 kΩ on both.
When turning the wheels or driving sloooowly ,before diagnoistics goes on strike, I am getting 1.8-3.5 on the left one, a steadier value from 2.1 to about 3V on the right one.

Robbed a sensor from a td5, was the same as the left one. Used it also in the other spot.
No difference.

Tried my brand spanking new Gap IID tool on it, doesn't even talk to my ABS problem. It did before I upgraded it though.

The only time these

lights went off was when my partner was spraying lots of diesel around to clean something. We have strong winds at the moment so the diesel went all the way to Australia and must have taken the lights by surprise. Never mind, they came back after 10 kms.

Result was that I had to give the car back today with a persisting problem.
Any ideas welcome. If it makes me look like an idiot, fine. I just have to fix it.

Maybe something related to this?

http://forums.lr4x4.com/topic/57111-...arning-lights/

P.S I know nothing about L/R

**annette** · 2017/04/12, 06:55 AM

Originally Posted by JuanB

Maybe something related to this?

http://forums.lr4x4.com/topic/57111-...arning-lights/

P.S I know nothing about L/R

thank you... but
I have done this

The earth problem use to be rust in the bolt or screw under passenger seat, the earth near the one from the ECU. Just unscrew it, some WD40 and tie it again, that must solve your problem. The Wabco unit is serviceable, they sell the shuttle valve around GBP 40, I think.

the shuttle valve works and as I said above, there is no more error since I fixed that earth. That is what is driving me nuts.

PS thank you for trying, today I felt like I know nothing about LRs. Sad thing is that is exactly what my partner seems to think today.

**JuanB** · 2017/04/12, 07:01 AM

Where did your partner spray the diesel? If that cleared the code even for a little while, it might point to a problem associated with heat - Relay or something else that is severely rusted.

**annette** · 2017/04/12, 07:10 AM

Originally Posted by JuanB

Where did your partner spray the diesel? If that cleared the code even for a little while, it might point to a problem associated with heat - Relay or something else that is severely rusted.

the diesel ended up on me all the way from the other side of the chassis, the engine, gearbox and just about everywhere.
It is something Rafa does when he is p...d off with somebody's work and he doesn't know what to do either. So he gets into cleaning mood.

You have a good point. The heat might really be a clue. No shortage of heat here in summer and some things in a Puma get really hot . Now if some component doesn't like that it could generate all sorts of wrong signals.

**sierrafery** · 2017/04/12, 11:44 AM

...I am getting 1.8-3.5 on the left one, a steadier value from 2.1 to about 3V....

If you are certain that the sensor is good you should make sure it's good contact in the ABS ECU plug on that sensor's circuit or replace the wiring to that sensor cos it's not normal for the voltage to drop below the self test level(2 - 2.4V) as the stationary voltage should only rise is not supposed to drop whatsoever... if these are ruled out next step would be another ABS ECU cos it can be a dry joint within it, the ECU is suspect a bit cos it should have stored a fault code for that as long as the 3 amigos are on unless it looses feed when the fauklt occurs so check the feed path to ECU too... unplug that left sensor and go for a short ride, if you dont get sensor related fault code then IMO the ECU is fubar'd , these WABCO D ECUs are not the most reliable beasts

btw

Made a better earth for the ECU including the black wire leading to the violet plug C0506 nº3

that's the reference earth through the modulator... the main earth to ECU is in C0504-12 from earth point C0362-1 so better check that first

**annette** · 2017/04/23, 03:15 PM

Solved it.
After getting the car back from the client I seized the opportunity to swap the ABS ECU against a TD5s that was in the garage. Noticed a difference in earth voltage.
I have recently rewired that td5 almost completely and noticed a difference between the Puma and td5 and wiring
So I went to enquire and there was a cable on top of the transferbox full of mud and grease making intermittent contact to the stupidly placed ABS earth cable.
They must have taken earth literally when they decided this in Solihull.

So ABS lights are all off now... After the client wasted a lot of money 2 years ago on sensors that another garage changed for nothing