Haven't tried that.

(The cable adjuster? connector) If so, I did unplug and check for corrsion and replugged it with no change.

 

No, leave it disconnected and drive the car.

If the problem goes away, you probably have an electrical wiring or ASR computer problem.
If the problem still happens, you probably have a mechanical problem in the adjuster.

Tom Piper

 

Sounds reasonable to me.
One thing I am afraid of is that it's the EBTCM since it controls what signals are sent to control the ASR and ABS. And according to the FSM it receives the RPM info from the PCM, which it uses to determine ignition retard control. What all this means to me is that there is a LOT of electronic control being handled by the EBTCM. (And I'm in way over my head when it comes to electronics).

 

I've actually disconnected the ASR/ABS computer completely.
It is designed to "fail" in a safe mode, in other words, the standard braking system is still functional without it.

In your case, the ABS should still function when disconnecting the servo -- but, ASR won't.

This test should at least narrow the problem down.

However, since you got a code from the computer saying there was a problem, my guess is your problem is the computer or wiring.
If I am right, the problem should go away when you disconnect the servo.

Tom Piper

 

I'll try this later today.

When you say computer, do you mean the EBTCM?

 

Yes.

Tom Piper

 

Last night I backed the car out and checked the DTC's. Had the 65 for Cable Adjuster Circuit malfuntion as before. I cleared the code. Started the car and no Service ASR light shows up, so I turned off the ASR and went for a ride. The Srvice ASR light stayed off UNTIL I stopped for gas. As soon as I restarted the car the Service ASR light came on.
At home I pulled the DTC again and got 65, same deal. Cleared it, started the car, no light, as soon as I moved the accelerator (very lttle, maybe a 1/4") the Service ASR light comes on. Cleared it again, this time I increased the engine speed at the TB on the engine, no light comes on and no code. Only does it when I used the gas pedal. So now it seems to me it might be in the cable adjuster mechanism?
I disconnected the electrical connector to the cable adjuster and I still got the Service ASR light, so this seems like the EBTCM may be the problem.

I did not replicate my original problem of not having any throttle. It worked fine with the ASR light on.

 

As I stated before, with the cable adjuster disconnected, it is normal to get a "Service ASR light" regardless if there was a problem with the EBTCM or not -- with the cable adjuster disconnected, you should completely ignore the Service ASR light -- it means nothing.
On a system working properly, if you disconnected the cable adjuster, you would get the "Service ASR Light."

If I understand you correctly, with the cable adjuster disconnected, the problem with the throttle relaxing does not happen.
If that is correct, the likely problem is the wiring or the EBTCM.

Tom Piper

 

Yes, to all you stated.

No matter what I did, I could not duplicate the "relaxed throttle" condition.

I REALLY don't want it to be the EBTCM since it's a pricey piece. But if it is, i'll have to get another one. First, I want to make sure it's not the Cable Adjuster. The diagnostic procedure in the FSM said to disconnect the electrical connector to the Cable Adjuster and measure the ohms at the cable adjuster. I assume that's at the connector and I assume you just connect each lead from the DVOM to the connector to measure the ohms (using the proper setting on the DVOM). The FSM says the measurement shoud be .5 to 10, not sure, since I don't have the FSM here. Of course, you disconnect all the cables first and turn the adjuster and let it return to it's nominal state before measuring ohms.

 

Your memory is pretty good, those are the OHM readings listed in my FSM. You are correct that the DVOM leads connect to the disconnected connector on the adjuster or servo side, makes no difference which lead goes to which wire connector. If your DVOM is not autoranging you will likely set it to the lowest scale.
The additional electrical checks are simply checking the voltage supply and ground to the adjuster and verifying that the wires are not shorted to each other or to ground.
The book mentions using the breakout box but you can do the checks at the adjuster too since there are only two wires. You will need to disconnect the connectors at the EBTCM for some tests, hope that helps.

 

This is what I understand you have determined so far (forget about the Service ASR light):
1) With the cable adjuster disconnected, the problem with the throttle never happens.
2) with the cable adjuster connected, the problem happens frequently.

The first thing this tells you is the motor in the cable adjuster must be working since it actually relaxes the cable when it is connected -- the cable can't relax unless the motor runs.

The second thing this tells you is, with the motor disconnected, the cable adjuster does not relax -- the motor can't run to relax it.

Therefore, there is an extremely high probability that the problem is not a mechanical or electrical problem in the cable relaxer.

So, there is a high probability there is a problem in the wiring or the EBTCM feeding the cable relaxer motor to cause the throttle problem.

At this point, it would be nice to have a good scan-tool that is designed to trouble shoot the EBTCM, but they are costly.
With the EBTCM main electrical connector removed and the cable adjuster electrical connector removed, I would use an ohmmeter to check the wires to the cable adjuster to see if any of them are shorted to ground.
If neither wire is shorted to ground, it is extremely likely the problem is the EBTCM.
Plus, if the wiring were the problem, I would expect the cable to relax as soon as you turned on the key.
Since the cable only relaxes after you push on the throttle, I am betting the EBTCM is defective or a sensor to it is giving faulty signals.

Tom Piper

 

That logic seems sound to me Tom. I would check the resistance of the adjuster mainly because it is an easy check unlike the EBTCM. Once that is eliminated, wiring and computer are all that remain.

 

Your comment about the input sensors got me thinking, especially since the OP mentioned the TPS, but from my understanding of what it takes to set the code the inputs should not be a factor.
I would take a good look at the connectors at the EBTCM, corrosion or problems there could cause the symptoms and the code.

 

I thank you both for your excellent help.

Maybe I was not clear on the throttle problem, i.e. not being able to get beyond an idle. It happened only once, but that was a situation I don't want to repeat.

I will check all that you both suggested and see what I find out.

Thanks again.

 

Can't blame you for not wanting a repeat performance, best of luck, keep us in the loop.

 

Since the problem still happened with the ASR turned off, it is very unlikely that the problem is a sensor.


Tom Piper

 

I am bringing this back to life as I have the same problem right now. ccs96 if you read this did you ever solve the problem? If so, what was the issue?

As I said I am having the same issue. At start up all is well, I can cycle the ASR using the button above the light switch to go from ASR on and ASR off. Once I push the gas the Service ASR and ASR Off lights come on. The come on using the gas pedel or giving it gas from under the hood.

This just started within the last few days after taking a 220 mile trip. I pulled the codes and got the 65 and also got 71 which is listed as internal EBCM problem.

Thanks in advance.

P.S. Never had a problem with not being able to press the gas pedel.

 

Fast Cop;
No I have never gotten it worked out.. I haven't the throttle refuse to work again, but same as you, start the car, no problem switching the ASR off/on, but as soon as I touch the throttle, the Service ASR light comes on. I have a corvette guru buddy that I am going to have look at it sooner or later. I hope it's not in the ECBM, I think they are hard to come by and cost big bucks. I really feel it may be the the cable control module, it's hard to come too, but for less $$.

If you solve this problem, please let me know and I'll do the same.

 

ccs96

Thanks for the response. I am going to check all the electrical connections and go from their. I also hope it is not the EBCM as new they cost about $750.00. Install is easy so I would not have to pay a dealer.

This weekend I am going to also pull the EBCM and check all connections to ensure they are clean.

I will let you know what I find out.

The fact that I could not find any post, other than yours, in reference to a DTC 65 and 71 tells me that this is a very rare problem.

Thanks again for your response.

 

Good luck.

I thought somebody else would have had the same thing happen also.
I know there was no code for the throttle position sensor, but I think it may be involved (my guru buddy says 'no' & he is extremely knowledgeable about vettes), but I have a feeling the TPS has something do with it since all you have to do is just touch the throttle.