TCS/ALB/handbrake and rear brake light warning lights

[scottg]

Hi all,

I have just purchased a 1993 NSX auto with a warning light issue. The car is fine for the first 5 mins of driving and then the handbrake(parking brake) and rear brake light bulb warning lights omes on, when you then press the brake pedal the TCS and ALB warning lights illuminate as well. This happens in the same sequence each time so I am sure the probs all point to one issue and I was wondering if anyone has had the same problem and can point me in the right direction?

Thanks in advance Scott

 

[Bram]

Scott, you can pull the codes from the ECU and post them, or check the code using the online manual.

My guess is that your speed sensor is gone.

Bram

 

[Briank]

I am thinking you have an issue with the gauge cluster. The same bad capacitor issues that affect the ccu and the speaker amp also happens to the gauge cluster. I would say swap in a known good unit but I think you finding one to do that will not be easy.

 

[scottg]

I will ask the garage that looked at the car to check for any codes again and update the post accordingly.
I also noticed the rear brake lights sticking on and so need to fix this as well

Scott, you can pull the codes from the ECU and post them, or check the code using the online manual.

My guess is that your speed sensor is gone.

Bram

 

[comtec]

Check your brake fluid level.

For the brake lights sticking look at the switch at the pedal. First check the pedal stopper that operates the switch. You can get info in this thread, it's for the clutch but it's the same piece on the brake.

Mike

 

[mastaf]

I had a similar problem a few days ago, and just changing the bulbs solved the problem.

 

[scottg]

Thanks guys the issue is still onging. The garage changed the bulbs and I have checked the brake light switch but not the pad so will look at that later today. I have noticed that when the ALB/TCS lights come on a little while after the handbrake and rear brake light warning lights I can hear the relay click over my left sholder

 

[Miner]

Thanks guys the issue is still onging. The garage changed the bulbs and I have checked the brake light switch but not the pad so will look at that later today. I have noticed that when the ALB/TCS lights come on a little while after the handbrake and rear brake light warning lights I can hear the relay click over my left sholder

Isn't there some "failsafe" in the NSX that driving with the hand brake engaged (pulled up 1 click so the light comes on) will after so many seconds disable the TCS? I seem to remember that being in the "Secrets" thread from way back.

If so, it sounds like the hand brake contact switch is not functioning properly.

Miner

 

[scottg]

Thanks for all the sggestions so far but the problem persists. I have changed all the bulbs, checked the fluid levels, bypassed the resevour switch and the brake light switch but the problem is still there. Any more ideas would be very welcome.

 

[I1O101I]

Hi all,

I have just purchased a 1993 NSX auto with a warning light issue. The car is fine for the first 5 mins of driving and then the handbrake(parking brake) and rear brake light bulb warning lights omes on, when you then press the brake pedal the TCS and ALB warning lights illuminate as well. This happens in the same sequence each time so I am sure the probs all point to one issue and I was wondering if anyone has had the same problem and can point me in the right direction?

Thanks in advance Scott

I have posted up all the service manuals.

hope this helps

http://www.nsxprime.com/forum/showthread.php?p=1633699#post1633699


Bryan

 

[I1O101I]

Hi all,

I have just purchased a 1993 NSX auto with a warning light issue. The car is fine for the first 5 mins of driving and then the handbrake(parking brake) and rear brake light bulb warning lights omes on, when you then press the brake pedal the TCS and ALB warning lights illuminate as well. This happens in the same sequence each time so I am sure the probs all point to one issue and I was wondering if anyone has had the same problem and can point me in the right direction?

Thanks in advance Scott

I have posted up all the service manuals.

hope this helps

http://www.nsxprime.com/forum/showthread.php?p=1633699#post1633699


Bryan

 

[scottg]

Still looking for a solution I am afraid. When we swapped out all the bulbs we noticed that the right hand rear cluster had a bulb holder recess that had melted at some time in the past, this added to a crack in the lense lead me to post a wanted ad and I duly purchased a good used light cluster. After installing this i drove a circuit that I normally do where I know when the lights come on and they didnt but on my way home up they came again.
I think its time to book the car into a good autoelectrician as I have run out of ideas and just want it fixed once and for all.

 

[comtec]

I hope with the melted housing you don't have wiring that was overheated to where they are shorting out.



The Brake indications are your problem because because both the ABS and TCS monitor that circuit for a failure and if detected both will disable. So fix the brake problem and the others will probably be ok.


Unplug the parking brake switch and the brake fluid level switch. With both disconnected check the Green/yellow stripe wire in the plug for the parking brake switch for ground with a volt ohm meter. If you don't see ground, reconnect the brake fluid level switch and check once more. If still no ground then disconnect the brake fluid level switch again and plug the parking brake switch back in. Check for ground on the Green/Red stripe wire in the plug for the brake fluid level switch, both with the parking brake off and then on. If you only see ground when the parking brake is on, then the wiring and both switches should be good which could mean a internal problem of the gauge cluster.

We'll try to fix this main thing first then figure out the other brake indication.

Mike

 

[scottg]

Thanks Mike.
I agree the abs and TCS is just triggered by the brake warning lights. I will carry out the tests you suggest and update the forum after the weekend

Thanks

Scott

I hope with the melted housing you don't have wiring that was overheated to where they are shorting out.



The Brake indications are your problem because because both the ABS and TCS monitor that circuit for a failure and if detected both will disable. So fix the brake problem and the others will probably be ok.


Unplug the parking brake switch and the brake fluid level switch. With both disconnected check the Green/Red stripe wire in the plug for the parking brake switch for ground with a volt ohm meter. If you don't see ground, reconnect the brake fluid level switch and check once more. If still no ground then disconnect the brake fluid level switch again and plug the parking brake switch back in. Check for ground on the Green/Red stripe wire in the plug for the brake fluid level switch, both with the parking brake off and then on. If you only see ground when the parking brake is on, then the wiring and both switches should be good which could mean a internal problem of the gauge cluster.

We'll try to fix this main thing first then figure out the other brake indication.

Mike

 

[comtec]

Your welcome Scott,
Do all the lights come on and then go back off when you start the car?

If you see a ground all the time you will need to disconnect the C437 harness plug from the gauge assembly and check again.



Fyi... The parking brake switch wire color changes to green/yellow stripe, didn't notice before. Updated the post above.

Mike

 

[scottg]

Hi Mike,
The lights all come on with igition and then go out when the car is first started. After about 5 minutes the rear brake light and hand brake lights come on and then when you accelerate to over 15-20mph the ABS and TCS lights come on. If I stop the car, turn of the ignition and re start the lights go out again and the same cyle will occur.

I purchased a volt meter on line last night to do th tests and I assume by ground you mean that when I connect the voltmeter to the wire and then the other terminal of the meter to earth I shouold get a reading? Sorry I am a total novice when it come to electrics so forgive the question

Kind Regards

Scott

Your welcome Scott,
Do all the lights come on and then go back off when you start the car?

If you see a ground all the time you will need to disconnect the C437 harness plug from the gauge assembly and check again.



Fyi... The parking brake switch wire color changes to green/yellow stripe, didn't notice before. Updated the post above.

Mike

 

[comtec]

Hi Scott,
No problem man.
Yes you want to touch one lead to the wire inside the plug and the other to a known good ground. Aluminum is not the best for conductivity so try to use one of the NSX grounding points as your earth ground. There should be one behind both the driver and passenger kick panels.

I don't know what VOM you purchased but you can use a resistance or a ohm scale to check. The resistance usually has a audible tone that will beep to show continuity so you don't even have to view the VOM display and with the ohm scale, zero/near-zero resistance is a dead short and that is what you are looking for.

Here is a basic voltmeter vid.

Mike

 

[scottg]

Thanks Mike, I will experiment at the weekend

Kind Regards

Scott

Hi Scott,
No problem man.
Yes you want to touch one lead to the wire inside the plug and the other to a known good ground. Aluminum is not the best for conductivity so try to use one of the NSX grounding points as your earth ground. There should be one behind both the driver and passenger kick panels.

I don't know what VOM you purchased but you can use a resistance or a ohm scale to check. The resistance usually has a audible tone that will beep to show continuity so you don't even have to view the VOM display and with the ohm scale, zero/near-zero resistance is a dead short and that is what you are looking for.

Here is a basic voltmeter vid.

Mike

 

[scottg]

Problem solved.
It was an earthing fault found by a local auto electrician after a 7 hour search.
Thanks for all your suggestions and help guys

 

[comtec]

That's great Scott, glad you got it fixed.

Mike

 

[scottg]

That's great Scott, glad you got it fixed.

Mike

Thanks Mike.
I t is such a pleasure driving the car without those lights coming on after a few minutes. Next challenge is a humming sound that I get after the car has run for a minute or two at low revs i.e below about 1500. Sounds like it could be a alternator bearing but if I put a long handed screwdriver to that and the other end to my ear it is not noisy. The engine lift hook to the side of that is so something is transmitting the sund to this area. Makes no difference if in drive or not (mines an auto)
Any suggestions anyone?

 

[comtec]

Just a guess because someone else mentioned it. Could it be?

LMA's

Mike

 

[Sudesh]

Thanks Mike.
I t is such a pleasure driving the car without those lights coming on after a few minutes. Next challenge is a humming sound that I get after the car has run for a minute or two at low revs i.e below about 1500. Sounds like it could be a alternator bearing but if I put a long handed screwdriver to that and the other end to my ear it is not noisy. The engine lift hook to the side of that is so something is transmitting the sund to this area. Makes no difference if in drive or not (mines an auto)
Any suggestions anyone?

From your post your thinking the sounds coming from somewhere at the top of the engine, but just as a suggestion [maybe you already checked] but is your AC ON? If so switch it off and see if the humming disappeared.

It's just a though, an NSX I worked on in the past was described to me as having a HUM at low reves, which turned out to be the AC compressor.

 

[scottg]

From your post your thinking the sounds coming from somewhere at the top of the engine, but just as a suggestion [maybe you already checked] but is your AC ON? If so switch it off and see if the humming disappeared.

It's just a though, an NSX I worked on in the past was described to me as having a HUM at low reves, which turned out to be the AC compressor.

Good thought sudesh but I am afraid it makes no difference on or off

 

[scottg]

I am afraid my celebrations were too early, I took the NSX out at the weekend after two weeks of terrible ewather and the car sat in the garage and the lights came back on. Called the autoelectrician and he sounded like he was running out of ideas having thought he had solved the issue. Back to the drawing board.