2.4D RWD ABS not functioning

[mattt429]

Morning all, I own a mk6 mwb rwd 2.4 duratorq. Today the ABS and park light (!) Stay on constantly after the engine has been started. My van is also skidding so the ABS has a fault somewhere.

The vacuum pump leaks a little, would this cause the ABS to go to fail safe?

Fluid is fine, but I remember reading somewhere that the parking light can stay on due to lack of fluid?

Im planning on changing the vacuum pump and new gasket but was just wondering if anybody could shed some light with anything else I could test?

Is there a way of testing the fluid level sensor?

Also if it helps, if I pump the brake pedal with engine off till the pedal goes hard, the pedal sinks down once I start the engine.

Regards and thanks in advance to anyone who can help.

[knobby1]

If your ABS system throwing up a fault light it may just be a faulty sensor at a wheel or possible broken loom. Get under the van and have a wee look at the sensors and their looms.

Vacuum pump will have no effect on ABS.... and it's normal for the brake pedal to go hard with engine off as you have no servo assist.

You can test your fluid level sensor by popping the sensor connector off and shorting the wires, this should bring the brake fault lamp on.

Also check all your fuses just in case one has given up..

Lord Knobrot

[Punto443]

I would suspect a faulty sensor or damaged ring, if you don't have access to diagnostic equipment, you could try a resistance check with a multimeter to compare the reading in the sensors, it may show if one is different?

[ned]

If the abs light is on the brake warning light will come on as it is warning you there is a fault with the brakes (you should also get a buzzing type noise).

My abs light is on due to a knackered sensor, to stop the brake warning light coming on I removed the abs fuse untill the new sensor arrives.

Have you had any work done on the brakes, wheel bearing etc.

Or are your pads requiring replacing. N

[mattt429]

Morning all and sorry for the delay in getting back to you

Lots of great advice here

So I got hold of a diagnostics tool , an elm 327 and its throwing up code C1145 (front right sensor)

Multimeter shows no resistance from the sensor wires, but the abs module has resistance from the plug to the sensor side plug. With any luck a new sensor should sort it out. Ill keep you all posted!

[mattt429]

Fitted new sensor, cleared dtc codes, light still on, even after a 30 mile drive no dtc after 30 mile drive


Checked fuses again, theyre all fine.

At my wits end now, am I dealing with a wheel bearing the wrong way round?

[mattt429]

Update:- Rescanned diagnostics and now have 2 dtc's

C1266 ABS - ABS Valve Power Relay Circuit Failure

And

PCM: P1631

Can anyone shed any light on this? Im guessing fuses and relays are next on the list.

Thanks

[knobby1]

Update:- Rescanned diagnostics and now have 2 dtc's

C1266 ABS - ABS Valve Power Relay Circuit Failure

And

PCM: P1631

Can anyone shed any light on this? Im guessing fuses and relays are next on the list.

Thanks

Still points to a wiring fault...I'd be going over all the relays & ABS looms to check for breaks or poor connections etc...

Lord Knobrot

[mattt429]

Cheers will have a look tomorrow

Sent from my GT-I9300 using Tapatalk

[mattt429]

Ok so im ready to roll my van with frustration

Can anybody tell me how to test the abs pump/module?

Ive found 3 lives going I to the pump, 2 read 12.65v the other (a red and black wire) reading 6v. This one goes into the instrument panel? Does anybody if this is correct as ive replaced the wire and still only getting 6v to it. Now have code C1266.

EDIT: Code C1266, sorry

To recap i have tried the following:-

Checked all fuses in passenger compartment (cabin)
Checked all fuses in engine compartment,
Removed, cleaned and replaced all relays.

After changing front right wheel sensor and clearing codes have removed wheel sensor code and then had a PCM code and an ABS code.

Checked wiring loom on n/s arch, looks fine all the way around.
Tested for live feeds going into ABS module. Found 3, 2 at 12.65V and one at 6.5V
Replaced wire between instrument panel and ABS module plug, still only 6.5V
After clearing codes PCM code has not come back since replacing this wire :S


Now stuck with Code 1266, sometimes i can clear it and it wont come back for a while, however the ABS light remains permanently on and the ABS not functioning.

[mattt429]

viewtopic.php?f=5&t=171837&p=1459932#p1459932


If anybody is still reading thia after my mad ramblings and are experiencing the same or similar problems please check the above thread based on fault code c1266.