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Does anyone know how if there is a way to troubleshoot the ABS system on 1994 VR4's without a MUT-II diaganostic tool?
Can the codes be read from the ECU without the MUT-II? I am pretty sure that you can get 1996 and new ECU's to display codes through the ABS light (flashing) via the Data Link port, but I am not sure about the 1994 version.

Any techies out there with any suggestions???

P.S. My ABS light does the proper:
1) Flashes 4 times when key ON.
2) On - when turn key to START.
3) When key returned to ON from START, flashes 4 times.

BUT...when car starts to roll (> 4 mph) ABS light comes on and stays on. Also I do not hear the Hydraulic Unit come on at this time. Removed and cleaned both front wheel speed sensors. My next check will be the hydraulic unit motor relay, but I'm just trying hit and miss stuff not knowing the codes.

HELP!!
 

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ABS

Your system sounds like it is starting to work properly. Once you take off first the system checks the wheel speed sensors, vehical speed sensor, g sensor. If these check out alright the system pulses the valves open/shut - if this works then the system is fine.

If your unit does not pulse the motor / valves - it hasn't passed the first test of speed sensors.

If you could be stuffed going to a Mitsu dealer and tell them you want them to plug in the MUT2, read off the code then send the reset command.

The fault code will be 1 of 4 wheel sensors, the vehical speed sensor, or g sensor.

If you can't be stuffed doing that - here's the DIY way...
Underneith the steering wheel just to the right there is the datalink connector. It is a 16 pin connector which is ttwo rows of eight. Top left pin is 1, moving along to 8 on the top RHS. Pin 9 is the lower left.

You want to ground pin 1 to have the ABS system flash out the codes via your ABS light. The service manual does not state clearly but I assume you do this with the ingition off, then turn the the key to on position but no starting.

This should pulse out the code. A long pause then flashes for the 10's and a shorter pause then the 1's. Let's say you ground the terminal, turn the key on and the light does the following:
long pause, 1 flash, shorter pause, three flashes.

Another example:
long pause, two flashes, shorter pause, six flashes.

26 is the code, indicating a fault with the G sensor.

If the light flashes on and off with .5 second intervals, this indicates no fault with the system.

Regardless - the fault is most likely to be a wheel sensor, either shorted or open circuit. This test will distinguish between the two. You could also test with a meter - you sound technically minded.

The list is long so post back your results and we'll take it from there. Once you have the code - lets try to reset the unit to see if the code comes back.

To clear the ABS unit fault codes without using MUT2:
This has to be done exactly as described with correct timing otherwise it wont work.

Car is off. ABS unit nolonger grounded via pin 1.
Sitting in the car with the key turned off.
Place foot on brake pedal.
Turn ignition switch to ON but don't start the car. The ABS light should come on.

To reset the unit - the brake pedal needs to be pressed & released 10 times, with less than 1 second gap inbetween presses. So that means 10 times in less than 10 seconds. If not done correctly the method wont work.

So after turning on the switch, still having your foot on the pedal:
Within 3 seconds - depress pedal and press again - this is the first press - repeat 10 times within 10 seconds.

If you have done the procedure correctly the ABS light will go off for 1 second, then come back on. This means the unit has been reset.

You could test the unit again via grounding the pin and checking that the fault code is 0 (light flashes non stop).

Cheers.
 

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Discussion Starter #3
DIY method.....

Does anyone know for sure that the grounding of pin 1 on the datalink port will work for 1994 models (or only for models 1996 and greater)? I too have the manual and I believe that it does not talk about this DIY method until the words "model year 1996".

I would hate to short pin 1 and find out that I fry the ECU.

Thanks for your input "Smart Arse". Let me know if you have any wise words.
 

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DIY method.....

Does anyone know for sure that the grounding of pin 1 on the datalink port will work for 1994 models (or only for models 1996 and greater)? I too have the manual and I believe that it does not talk about this DIY method until the words "model year 1996".

I would hate to short pin 1 and find out that I fry the ECU.

Thanks for your input "Smart Arse". Let me know if you have any wise words.
Resurectibg a super old thread. Did you ever figure this out? I'm suspecting a wheel speed sensor on my 91TT but, like you, don't want to harm my ecu.
 

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You will not harm the ECU, just follow this guide. It has a great write up of how to get the codes:
I was able to pull ecu codes but not abs or srs with a multimeter. One read constant voltage and one read no voltage. I heard rumor that you need an MUT to read abs or srs codes. Too bad they are extremely expensive. I had a project BMW a few years back where I was able to get a cable and an old windows xp laptop plus a some software to talk to all the systems. Didn't like the car as much but I sure liked being able to pull and reset codes. It would even let me set off the airbags from the computer interface which made me a bit nervous.
 

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One thing that has happened in the 20 years since this thread was posted, is BlackStealth built a very affordable scan tool capable of talking to all modules in the car...

 

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One thing that has happened in the 20 years since this thread was posted, is BlackStealth built a very affordable scan tool capable of talking to all modules in the car...

Agreed. I have one on current order with Antero for a local customer but will be picking one up for myself as well in the near future. You should check out the manual for it and see the codes it can diagnose.
 

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Agreed. I have one on current order with Antero for a local customer but will be picking one up for myself as well in the near future. You should check out the manual for it and see the codes it can diagnose.
I just ordered a snap on Mt2500. I'm excited to see what I can do with it.
 

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The scantool works pretty well. Admittedly, the last time that I used it was last May lol... tested on Dustin's '96 R/T Turbo with CloneECU:

288844
288845
 

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I have Antero's (BlackStealth's) Scantool and its great. I can scan all onboard computers (ABS, SRS, AC etc. etc.) with or without the stock ECU in place. I highly recommend it.
 
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