Warning lights when the engine is up to temperature?

[nhudson1]

Ford Focus Mk3 1.6 diesel 115hp 2012 112k (w/Rear Drums)

I have had an issue the past few weeks with an intermittent ABS/TC/TPMS/Stop-Start/Hill Assist warning on the dash... which after time became more and more permanent.

Codes are for the Rear Left (Passenger) Wheel (C0037)

I've replaced the Hub, Sensors and the underbody wiring extension... none of which worked.

Trying to get an appointment at Ford for a diagnostic session, 3 week wait. It went in, they "found" a corroded plug at the under body extension and replaced it. The car seemed fine for 24 hrs (30 minutes of driving) and then on the motorway the same warnings popped up.

Its back to being very intermittent rather than more constant and I think it now it might have something to do with the engine temperature? It only seems to pop up now after the car has finally reached normal operating temperature. It will come on for a few minutes / miles and then reset itself.

Am I maybe looking at the ABS module itself? Its booked in at Ford, again got to wait 2-3 weeks and its a further investigation so double the cost of a basic diagnostic session.

Any thoughts or ideas are GREATLY appreciated! Thanks in advance!

[E-bmw]

Have you got/do you know anyone with a code reader that can access "live data"?

If so try reading the wheel speeds with the car on the road over various speeds as you could have a wheel/tyre reading differently enough to go outside of its spec.

Had this on a car a few years ago when I bought a car & someone had fitted a slightly differently sized tyre.

[GreenV8S]

If you swap the wheels on that axle, does the fault code switch sides?

[nhudson1]

GreenV8S said:

If you swap the wheels on that axle, does the fault code switch sides?

I haven’t tried that, but I’d have thought it would happen sooner rather than later? It takes 15-30 mins at the minute, motorway or casual driving.

[LimSlip]

nhudson1 said:

Ford Focus Mk3 1.6 diesel 115hp 2012 112k (w/Rear Drums)
The car seemed fine for 24 hrs (30 minutes of driving) and then on the motorway the same warnings popped up.

This is the exact same symptom I had on a Smart car which was caused by the steering angle sensor being out of calibration. If would never cause a problem around town or on twisty A/B roads, but a few miles on a DCW or motorway and I'd get a warning light and no ABS or stability control. This is because the mismatch between the yaw sensor and steering angle is stable and can persist for long enough when driving in a straight line.

[AdamIndy]

LimSlip said:

This is the exact same symptom I had on a Smart car which was caused by the steering angle sensor being out of calibration. If would never cause a problem around town or on twisty A/B roads, but a few miles on a DCW or motorway and I'd get a warning light and no ABS or stability control. This is because the mismatch between the yaw sensor and steering angle is stable and can persist for long enough when driving in a straight line.

Yep, I had the same, it’s very common on BMW’s. Got the wheel alignment done, reset it, it never came back on.

[nhudson1]

LimSlip said:

This is the exact same symptom I had on a Smart car which was caused by the steering angle sensor being out of calibration. If would never cause a problem around town or on twisty A/B roads, but a few miles on a DCW or motorway and I'd get a warning light and no ABS or stability control. This is because the mismatch between the yaw sensor and steering angle is stable and can persist for long enough when driving in a straight line.

Interesting, so going in a straight line, it thinks something is wrong?

[stevieturbo]

Really it needs a competent garage it check it out....sadly very much a rarity to find.

It could still be a communication issue/wiring/connector/damp etc

[nhudson1]

Yeah, it’s on its third now. Ford have 2-3 weeks waiting between appointments

[LimSlip]

nhudson1 said:

LimSlip said:

This is the exact same symptom I had on a Smart car which was caused by the steering angle sensor being out of calibration. If would never cause a problem around town or on twisty A/B roads, but a few miles on a DCW or motorway and I'd get a warning light and no ABS or stability control. This is because the mismatch between the yaw sensor and steering angle is stable and can persist for long enough when driving in a straight line.

Interesting, so going in a straight line, it thinks something is wrong?

Driving in a straight line allows the system to detect small steering angle errors. When you are regularly steering left and right in a city or B road, small offsets in the angle sensor are lost in the normal variation of tyre slip angles.

[stevieturbo]

nhudson1 said:

Yeah, it’s on its third now. Ford have 2-3 weeks waiting between appointments

3rd garage, or 3rd competent garage ?

Main dealers rarely fall into the latter category.

[Baldchap]

GreenV8S said:

If you swap the wheels on that axle, does the fault code switch sides?

Be careful though, as the tyres might be directional.

[nhudson1]

Baldchap said:

Be careful though, as the tyres might be directional.

Haha 3rd garage, I went local independent first, then Ford.