make sure the tester is working
Auto X-Ray Vehicle Not Responding
Thread Starter
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Auto X-Ray Vehicle Not Responding
Just like it says. Any ideas on where the ALDL leads to in the ECM so I can check if the wires are good? I know I got the year right at 91 and 4th digit is Y but it still says not responding. Possible bad ECM but I changed it to a GM rebuilt one and still no luck. Where to go with this?
Drifting
Joined: Nov 2002
Posts: 1,593
Likes: 0
From: Mobile AL
St. Jude Donor '05
The ALDL connector is just part of the wiring harness that connects to the computer. If the rest of the car is working, there's no reason that the ALDL should not connect (unless there's a bent/dirty pin - check that out). ALso, hook the AUTOXRAY to another vehicle and make sure that it is functioning properly. Keep us updated on progress.
Instructor
Joined: Nov 2003
Posts: 102
Likes: 0
From: Fountain Valley CA
Had the same problem with mine; couldn't get it to communicate with my 89. Talked to the tech at Auto Xray and, in a nutshell, he said that their unit will not work on a 89. He gave some technical reasons but I'm not too swift on "baud" speak.
I thought it might be a bad unit, so I got another one(Corvette Central) and it did the same thing. Got my money back.
I thought it might be a bad unit, so I got another one(Corvette Central) and it did the same thing. Got my money back.
Thread Starter
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Originally Posted by gvajgrt
The ALDL connector is just part of the wiring harness that connects to the computer. If the rest of the car is working, there's no reason that the ALDL should not connect (unless there's a bent/dirty pin - check that out). ALso, hook the AUTOXRAY to another vehicle and make sure that it is functioning properly. Keep us updated on progress.
Drifting
Joined: Jun 2001
Posts: 1,704
Likes: 459
From: Mass Mass
I have two AutoXrays, a very old OBDI and a newer OBDII.
The older one works with my 1988 the newer one didn't.
Found the older would flash 10K resister between ALDA terminals A and B when you pressed the scan button, the newer OBDII scanner did not.
The older 165 ECM's needed this to start communicating.
That's the problem with the 89, don't know if your 91 needs the same thing.
Maybe someone else does?
I jury rigged a 10K between A & B and got the newer one (OBDII) to work also.
I've moved on to Datamaster and an AKM cable for the vette, but still use the AutoXrays for other cars.
The older one works with my 1988 the newer one didn't.
Found the older would flash 10K resister between ALDA terminals A and B when you pressed the scan button, the newer OBDII scanner did not.
The older 165 ECM's needed this to start communicating.
That's the problem with the 89, don't know if your 91 needs the same thing.
Maybe someone else does?
I jury rigged a 10K between A & B and got the newer one (OBDII) to work also.
I've moved on to Datamaster and an AKM cable for the vette, but still use the AutoXrays for other cars.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
My Auto Xray often does this with the Vette, but plugging and unplugging it, wiggling it up and down, or gripping the rear of the ALDL from behind and holding the connectors firmly together gets it working. Once it's communicating, it operates fine, even if I'm driving it. My best guess is that the contacts are worn out or spead too far apart from sticking too many paperclips in it - who knows.
The serial data line for the '89 is orange, terminal E (second from the left, upper row). It's spliced to the Cluster and if it's open, you usually don't get MPG or Range functions. It terminates at ECM Pin A8. If the ECM is bad, it usually won't flash a Code 12 or give a Check Engine Light. The other ECM wires are B, white/black or diagnostic link to ECM Pin A9; and A, black/white which is the ground to ECM Pin D3.
The serial data line for the '89 is orange, terminal E (second from the left, upper row). It's spliced to the Cluster and if it's open, you usually don't get MPG or Range functions. It terminates at ECM Pin A8. If the ECM is bad, it usually won't flash a Code 12 or give a Check Engine Light. The other ECM wires are B, white/black or diagnostic link to ECM Pin A9; and A, black/white which is the ground to ECM Pin D3.
Thread Starter
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Well, I emailed Auto X-Ray and they said:
The only thing I can think of at this point is that there may be cross over part #s for OEM ECMs for 1991my. In other words 1989-1992 ECMs may be interchangeable for this veh. Since we can't be 100% certain the ECM is indeed "1991" Y body may I suggest you try
configuring the scan tool for a couple of different years within this range.
May I also suggest an alternate 8th VIN code. I presume the 8th VIN
character for this veh. is "8" if so try using "7" or "J" . Another
possibility is that the same engines were used in "F" bodies as "Y" bodies
try selecting "F" for the forth VIN and "8" as the eighth VIN as opposed to "Y" and "8".
I talked to them and they said try different years. They also had me reset the entire unit by powering it off and taking out the last battery and hitting the "Power" button. Then they had me reconfigure the unit. I also tried to push the ALDL connector in and this time I hit paydirt. All works now. Especially thanks to Suncr's suggestion of pushing the plpugs together.
The only thing I can think of at this point is that there may be cross over part #s for OEM ECMs for 1991my. In other words 1989-1992 ECMs may be interchangeable for this veh. Since we can't be 100% certain the ECM is indeed "1991" Y body may I suggest you try
configuring the scan tool for a couple of different years within this range.
May I also suggest an alternate 8th VIN code. I presume the 8th VIN
character for this veh. is "8" if so try using "7" or "J" . Another
possibility is that the same engines were used in "F" bodies as "Y" bodies
try selecting "F" for the forth VIN and "8" as the eighth VIN as opposed to "Y" and "8".
I talked to them and they said try different years. They also had me reset the entire unit by powering it off and taking out the last battery and hitting the "Power" button. Then they had me reconfigure the unit. I also tried to push the ALDL connector in and this time I hit paydirt. All works now. Especially thanks to Suncr's suggestion of pushing the plpugs together.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
