Intermittent abs and tc lights on

NedHan79 · 25 Mar 2019

For the last few runs out I've been getting these lights on. Not all the time but more often than not. I'm assuming it's probably an abs sensor but this has only started since I change the steering wheel, but I'm not sure if it came straight on.
Is there any tools available to plug into the obd port( if it has 1)
Any other recommendations for home detection?

peterzoom · 25 Mar 2019

Maybe worth putting a replacement brake pedal switch in, about £15.00 and a reasonable first port of call in the absence of a scan tool.

NedHan79 · 25 Mar 2019

Are they a known issue?
I have noticed that there's less chance of the lights coming on if my foots on the brake pedal when I turn the key.

deMort · 25 Mar 2019

Ok .. a couple of contradicting comments from your first post to your second post ..

Do you get a warning message when you start the car or an intermittent message when you are driving the car ..

From your second post it would seem on first start up ?

Not aimed at you but a small thing that bugs me a bit .. please .. please .. always put every detail you can possibly think of in the first post .. including what actual car you have .. 997 and there are x2 gens of car and both are very different .

I've often answered a post here only to have a bit more detail drip fed on the next post .. then again on the third post .. i do my best but i need all the info .. it stops me having to guess at a fault only to have a bit of detail i needed added later and so on .. and everyone that also answers is in the same boat .

I will say .. i have given up on posts in the past as i got fed up .. i just don't have enough time to keep going back on posts and be drip fed .

Im ranting .. sorry young man .. its not aimed at you .. i get frustrated at times .. i do my best in a very short amount of time that i have and info is the key to getting the fault found asap .

The system has 2 ways of checking .. on first start it runs a system check .. anything open circuit .. high resistance will be flagged on this check.

The second is when the car is moving and above 6 mph .. it then looks at wheel speed sensors .. so a discrepancy on a sensor will be flagged at that point .. hence knowing when the fault happens helps a lot ..

If when moving then a speed sensor or ring on the driveshaft could be at fault ..

if on first start then its a possible break in a wire or again a wheel speed sensor but high resistance .

X2 ways of checking and both involve a tester to see whats going on .. there will either be a fault code or when driving you will see a difference on the wheel speed sensor outputs .. it can be a sensor , a driveshaft ring .. a brake pedal switch or indeed something more involved .

PSM light on but no fault code means the car thinks a wheel has started to lock up . it reacts as its programed to do , no fault code .... a fault is just that .. it sees something it doesn't like in a situation that it shouldn't see .. it will log a code ..

Info is the key here to working out the fault .

Once again .. not aimed at you ..

Its 8.30 .. i log at 9 and have just seen x2 pm,s .. i've already answered 3 tonight and i've not got to the boxster , cayenne section yet ..

Frustrated at my lack of time to answer questions basically .

Gonna log off early .. too many questions .. need a break .

Pickse · 25 Mar 2019

As DM says you need to know what, if any fault codes are logged before deciding which action to take.

Mine was logging 'Front Right Wheel Sensor Implausible' (or similar words)
My symptom was that I often got the lights on after I'd hit a bump with the front wheels, never on start and (I think) always reset after ignition was turned off.
My indy diagnosed an abs sensor but no joy it was the sensor loom, for which there is a repair kit available.

I'd get the codes read and go from there.

Cheers,

NedHan79 · 25 Mar 2019

Sorry guys. I usually don't have a lot of time so these questions are fired up quick.
My cars a 996.1 1998 3.4 c2
By intermittent I mean it's always on start up, but not every time I start it.
It never comes on when driving. If it wasn't on when the engine was started, it won't come on when moving.

I appreciate the help guys :thumb:

Intermittent abs and tc lights on

NedHan79

Suzuka

peterzoom

Spa-Francorchamps

NedHan79

Suzuka

deMort

Monaco

Pickse

Nurburgring

NedHan79

Suzuka

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