Warning lights

[jsbihn]

Hey all,
I am curious what is going on here and what can be the fix....
I have two warning lights come on - the traction control light and the ABS.
BUT! it is not a continuous code.
I run the my ELM 327 scanner when the lights are on and there is no codes (ok, I know HumTech told me the 327 doesnt scan that deep)
AND once the rig is shut off and then turned back on the light go away.

Plus it only seems to turn the lights on when I hit a bump hard, or drop off an incline kinda hard. Normal roading and what-not... doesnt cause anything.

What do you think?

[citiboy]

Have the same situation. Intermittent ABS/Traction Control light ON. I scanned it with my Tech2 and i have to replace the RR wheel sensor...parts on order.

Sorry, i erased the code and forgot to write it down.

[guruerror]

Originally Posted by citiboy

Have the same situation. Intermittent ABS/Traction Control light ON. I scanned it with my Tech2 and i have to replace the RR wheel sensor...parts on order.

Sorry, i erased the code and forgot to write it down.

Question for you...does your Cruise Control currently work? I've had these lights for a while...and suspected a rear wheel sensor at first, but noticed that my cruise control works fine. My logic was that Cruise Control would NEED the wheel sensors to function properly...so I'm wondering if your CC is working or not.

Perhaps I was on the right track at the beginning.

[citiboy]

Yes, my cruise control normally works, but i never tried to put it ON when the ABS/TCS light was ON.

Before i erased the code, i checked the ABS/TCS snapshot from the Tech 2 and found that the RR wheel sensor speed is 0km while the 3 sensors at 55km.

I first check the wiring from the RR wheel sensor to the EBCM and found no problem as per GM service manual flowchart.

I just changed the RR wheel sensor, road test with the Tech 2 and all wheel sensors reading are the same.

It's all good for now.

....from Mitchell OnDemand

The following are the main components of the Cruise Control System:
 The accelerator pedal
 The stop lamp switch
 The body control module (BCM)
 The cruise control switches
 The engine control module (ECM)
 The throttle actuator control (TAC) motor
 The vehicle speed sensor (VSS)

Cruise Control Inhibited
The engine control module (ECM) inhibits the cruise control operation when any of the following conditions exist:
 The ECM has not detected a brake pedal activation from the body control module (BCM).
 A Cruise Control System DTC has been set.
 The vehicle speed is less than 40.2 km/h (25 mph).
 The vehicle speed is too high.
 The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear.
 The engine RPM is too low.
 The engine RPM is too high.
 The system voltage is not between 9-16 volts.
 The Antilock Brake System (ABS)/Traction Control System (TCS) is active for more than 2 seconds.

[jsbihn]

Please remember these lights are intermittent

Like currently I have been driving with them off. they only light up if i hit a bump hard, and a restart resets them.

I havent tried the CC yet, but will tommorrow

[citiboy]

That's what i said on my first post...intermittent ABS/TCS light comes ON whenever it wants to come ON and when i switch the ignition OFF for about 10 mins. the light is OFF.

If you scan it with Tech 2, you can get the code and review the snapshot. That way, you can see what is the condition when the light came ON.

Sorry if i hijacked your thread.

[guruerror]

Originally Posted by citiboy

Yes, my cruise control normally works, but i never tried to put it ON when the ABS/TCS light was ON.

Before i erased the code, i checked the ABS/TCS snapshot from the Tech 2 and found that the RR wheel sensor speed is 0km while the 3 sensors at 55km...

Yeah...my Tech2 can't even communicate with my ABS...guess my probs are bigger than a wheel sensor.

[jsbihn]

not a hijack citi....
I welcome information like this.
Probably more than what i might have gotten on another forum.
So basically i need to get a tech2.... do you know where they are sold or how i can find them?

I have a feeling my problems are related to a sensor that on hard bumps gets loosen or it shorts for a second or something because since those two times... I havent gotten any issues.
Of course, that to mean doesnt mean dont fix it... there is a problem just not something that effects me immediately

BTW CC does work fine

[citiboy]

I got my original Tech2 Pro kit used from a small garage that went out of business. As a certified Honda/Acura Master Tech, i need this scanner to fix my own truck as the Honda/Acura HDS won't communicate with GM protocols even on generic mode.

Get it scan and review the snapshot, that way it's easier to tell if one of the sensors is not functioning properly or it could be from one of the sensor circuits.

Since i replaced the RR wheel sensor, i put around 400km on the truck and the ABS/TCS light never came ON.

I will be driving to Boston this labour day weekend and will report back.

[citiboy]

Update....

Just came from a 1200km trip and no ABS/TCS light came on. 14.7mpg, used to get 16mpg with oem tire set-up.

[jsbihn]

Citi,
Since I dont have a Tech2... is there only that one place for it to fail? Or is there other areas that this could fail?
My lights went from on intermittently to coming on after maybe 10 minutes worth of driving yesterday... this time it doesnt even take a bump to sit it off.

Any comments/suggestions would be great!!

[citiboy]

jsbihn,
It's hard to tell which part of the abs/tcs system is faulty without a scanner. I'm guessin' it's one of the wheel sensor but which one of the four. It also could be the wheel sensor circuit, again which one?. If you find a scanner that will read and access the wheel sensor output then you're golden.

Sorry, that's all i can tell you for now, let me know if you need any more info.

Goodluck!

[jsbihn]

Guru, Citi, HT....
Would this Tech2 work on my 03 H2 and 99 Corvette and be able to read all the codes?

http://www.obdiiscanner.com/professi...gm-tech-2.html

and do i need cerain things with it and or a CANDi module?

[citiboy]

jsbihn,
If you want to try it...go ahead...for me, i'm not a fan of those chinese knock-off. Let me know how it goes.

Citi