mswasty

Hello all,
My 1994 has a "Service ASR" light. When I start the car, it's off. As soon as I hit the gas, the light comes on. Has anyone had a similar issue? Trying to find info on the ASR system is like pulling teeth. Does anyone have any ASR info?

Another question?? Do I need a special scan tool to look at ABS/ASR trouble codes? I did a normal scan with Freescan and there were no codes.

Much Thanks
Matt

ztrips

I remember reading a procedure to "reset" the preload on the ASR unit. Something about putting a small allen wrench in a hole to line up the ASR cams and then torque the whole thing to a given setting. Sorry I can't be more help, but maybe it will job someone's memory on the subject...

Fabinatl

My 92 does the same thing! Let us know how to fix this.
Thanks,
Andy

Jet-Jock

Doesn't 94 have ODB 1 1/2?

If so jumper the connector and pull the ASR/ABS codes to determine the problem.

clf93lt1

did you check the break fluid

mswasty

My corvette manual says that you need a scan tool to extract codes for 1994. 1993 was the last year that you could use the on-board diagnostic feature. Too bad for me...

I did check the fluid in the master brake cylinder and it was OK. Is there a different brake fluid system for the ASR/ABS or does it all run off the fluid in the Master Cylinder?

I also checked the wheel speed sensors. They were OK. If you unplug a sensor, the ABS light also goes on. Mine isn't on, so I assume it isn't the wheel speed sensors.

Any ideas?

Thanks again
Matt

Grand Trunk

Check your vacuum lines. Could be some rot there.

mswasty

UPDATE:
I took my 1994 in to have the ABS codes read from the EBTCM and it showed a DTC code 65 "Adjuster Assembly Circuit Malfunction".

I would greatly appreciate it if someone could look in a 92-96 service manual to let me know what this is? I can't find anything on the web...

Thanks in advance!
Matt

Jet-Jock

The adjuster assembly circuit provides both power and ground to the adjuster assembly to help control engine torque during an ASR event.
A DTC 65 will set if CKT 1685 or CKT 1686 are shorted to ground, shorted to B+, shorted to each other or both open at the same time. The ASR system will be disabled for the remainder of the ignition cycle and the Service ASR lamp will illuminate.

The circuits come off the EBTCM gray and tan wires to the adjuster assembly- throttle and cruise control cables.

Does that help?

mswasty

Thanks so much for coming through with some info. I look foward to pulling my car apart tomorrow. I'll send an update when I find something.

mswasty

93JetJocky,
Great info on those ABS circuits. Where can I get a detailed schematic that shows that circuit information? Would the 1994 Factory Service Manual have it. If so, I'll pick one up on ebay. I did trace and test the gray wire (EBTCM to Throttle
) but didn't have any luck with the tan wire. (Cruise Control solenoid to EBTCM).

Thanks again
Matt

Jet-Jock

Yes Matt that info came from the GM Service Manuals. They are really detailed and accurate, and a must have for service work. Especially the electronics and diagnostics.

Lani

mswasty

UPDATE:
I found the problem and fixed it. DTC 65 means that the Adjuster Assembly circuit is malfunctioning but that code will also be thrown if there is a bad power feed or ground to the EBTCM. There is a red cable that comes from the fuse block (20A ABS/ASR ECU) and goes down under the battery to the back of the car. The ASR/ABS cables run under driver side door inside the lower body panel at the bottom of the car. It then comes out near the rear left wheel well and enters a grommet into the ABS/ASR compartment. The cables are ran in black Flex Tube in the wheel well and this tube was FULL of dirt and rocks. I pulled the flex tube off, cleaned it out to find the red power feed cable was shorted out. Abrasion and moisture I guess. I spilced in a new power cables and everythings normal. Thanks for all the help.

Matt

myvettesblue

mine was doing that i put some brake fluid in it and voila fixed

cousinit99

Old thread, I know, but after dealing with the same issue (code 65, Service ASR), I have to say that mswasty is dead on. The second I started wiggling that corrugated conduit tubing by the rear-left wheel well, all kinds of crap began to fall out. As soon as I saw the green corrosive dust starting to fall, I knew I'd found the culprit. That 18-gauge solid red wire was the source of my problem, too. There was nothing left of it at one point. It was corroded into two pieces. There were a couple other wires with exposed copper as well, but they weren't nearly as corroded as the red one was. For some reason, it's especially susceptible to corrosion. If it's exposed to the elements even the slightest bit, you're going to have a problem.

The floor was clean before I started..

daddysvet92

My 92 does the exact same thing, I'm going to have to read this all over again very slowly and see if I can find the same problem!!!
When I start the car there is no light, but as soon as I press the throttle the ASR light comes on, its been bothering me for awhile, but all I did was push the button and shut off the ASR and the light would not come on, does this sound like the same thing you guys have experienced?

Thanks
Chris

cousinit99

Yes, same thing to a T. If you hit the ASR button as soon as you start the engine, the Service ASR light won't come on. You'll probably have to undo the first 4 T-15 torx screws closest to the driver-side door in the wheel well so you can get at the first part of the conduit tubing, but if I had any money to spare at all (), I'd be willing to bet that you'll find something wrong in the vicinity of the rear-left wheel well. And if for some reason there's nothing wrong there, I'd check inside the ABS/ASR compartment directly behind the driver's seat. I found some corrosion on the terminals of the larger harness connector as well..

Good hunting..

daddysvet92

Thanks for the responce, I am excited to find this problem and fix it, I maybe contacting this thread if I get lost at all, I'll let you know what I find.

Thanks again!

Chris

springer-

Well this is has sparked me to try and fix mine. I was just going to use black electrical tape over the lights since I will always keep the ASR off anyway but now I will go looking for the problem.

Thanks

powerdmos

Hi All,
Just want to thank everyone on this thread who contributed in uncovering the CODE 65 issue!

After checking the continuity of the wires fron the EBCM connector to the ASR motor and all the connections from the EBCM to the output of the all the connectors, I was at a stand still.

After reading this thread, sure enough the RED Battery feed to the EBCM was corroded and open right around the rocker panel by the rear of the drivers door. You could see that the insulation was void and green copper was exposed.

If anyone would like more photos, etc,info, send me an Email.