ABS light random and idle question

vovo850 · Post by **vovo850** » 07 Apr 2019, 08:11

Here in the last weekish my ABS light has randomly come on. Let me attempt to explain.
I start the car, it's idling and within 10-20 seconds of it starting the ABS light will come on
and the open door chime will sound at the same time.
It only has done it twice now but it's kind of weird to me, especially with the chiming.
I have never had to mess with ABS module yet. Maybe it's getting to that time?
But the chime makes it weird and has me wondering if its electrical gremlin.
Or is that normal?

2nd question. The car after starting up and driving a short distance (to stop sign or around the block)
will randomly have the idle increased to about 1k rpm.
A punch of the gas pedal drops it down and generally that is the end of it.
Sticky cable or IAC?
I took the IAC off and sprayed it out with brake cleaner about 5-6 months ago
when the car was throwing a bunch of codes due to a bad MAF.
my check engine light is on due to a bad O2 sensor. (I'm a bad owner its been like that for longer than I care to admit)
Since it's random I didn't think it was enough to check but now after posting this
DING DING I should probably check..

Post by **erikv11** » 07 Apr 2019, 08:50

(1) The only obvious connection I can think of between ABS and the door chime is the electrical portion of the ignition switch - has it ever been changed? Does it feel "loose: to turn the key? Can you alter the behavior by jiggling the key a little bit?

There may be less obvious connections too, see what others come up with ...

(2) The amount of time you describe here is about the amount of time it takes for the car to warm up enough to start using the information from the front oxygen sensor, i.e. to go into "closed loop" operation. My interpretation/speculation is the bad O2 sensor leads to an air:fuel that bumps up the idle, then the ECU adjusts fuel trims to compensate and "fixes" the idle. You'd need to fix the oxygen sensor, and/or do some more troubleshooting (O2 sensor codes are often not the sensor, but yours may be). This assumes the CEL is for the front oxygen sensor, not the back one.

On the troubleshooting front you would also want to look at the engine coolant temperature (ECT) sensor, and for vacuum leaks.

vovo850 · Post by **vovo850** » 07 Apr 2019, 09:21

No I haven't replaced the ignition switch and it doesn't feel loose.
Next time it should happen I'll try to remember to jiggle it.

The CEL is for the rear sensor that has been bad. I never bothered with it since the car always seemed to run ok.
Even though the new sensor has been sitting in the box for years.. (lazy owner)
But the front one could be starting to go bad, so that is something to look at when I pull codes.

Interesting that you bring up the ECT. That has been flaky for a while now and I will lose
the temp gauge on the cluster. It will work and than just flat line and repeat.
At least I assume the gauge and ECT are related.
That has been flaky longer than this new condition with the random idle so I didn't correlate the two.
Unrelated but disclosing my thermostat has been stuck open and I have the notorious stripped bolt on the housing.
So really need to get all that fixed anyway..

vovo850 · Post by **vovo850** » 10 Apr 2019, 10:09

Update on the ABS light.
It came on yesterday and didn't go off till I restarted the car.
Wiggling the key didn't do anything, ignition feels pretty tight and not loose at all.
When the light came on, I had no turn signals at all.
No clicking, no light out indicator, nothing.
I'm not sure about the other lights because I didn't realize the ABS was even on until I was on the road.
I was wondering if it was the ABS module but I don't think so at this point.

Post by **abscate** » 10 Apr 2019, 13:33

The electrical part and the mechanical part of the ignition switch are isolated, so jiggling won't help much

Look for the DIY on the electrical part and it shows how to take it apart and test it - its a $50 part if you decide to replace it.

vovo850 · Post by **vovo850** » 10 Apr 2019, 16:43

viewtopic.php?f=1&t=80191
This post?
Yes I could see that being the issue
I only ever use 1 key in my ignition and have 181k on it. Probably original part

Post by **erikv11** » 10 Apr 2019, 17:55

abscate wrote: ↑10 Apr 2019, 13:33 The electrical part and the mechanical part of the ignition switch are isolated, so jiggling won't help much ...

Jiggling or slightly rotating the key back and forth helps out a ton, many users have determined this empirically.

Post by **Matty Moo** » 10 Apr 2019, 19:26

It's a 95.....pull the abs codes from the dtc box under the hood.

vovo850 · Post by **vovo850** » 10 Apr 2019, 20:53

Matty Moo wrote: ↑10 Apr 2019, 19:26 It's a 95.....pull the abs codes from the dtc box under the hood.

I'll pull codes but I really don't think it really is ABS related.
It sounds like ericv11 and abscate are closer to the real issue.
especially since this started, the car won't shift out of park randomly without hitting override.
Which just started happening on Tuesday.
Sounds like I need to replace the electrical part of the ignition switch sooner than later.
I'll wiggle it more, but if it's pitted I don't see how that will clean the pits up.

Post by **erikv11** » 10 Apr 2019, 21:26

Ah I see the misunderstanding: the wiggling or slight turning is to possibly help figure out if it is broken - not to clean it up.