Help! Problem with connection between ECM and Scanner!

[91vettecks]

adHi Friends,

Well, i have a big problem here. Some weeks ago my Corvette 91 Aut 350 LT5 starts a high idle rpm ( 3188 rpm) and bad throttle reponse. I bought a Actron Scanner and try to connect with the ECM but i can´t stablish a connection. I consulted the GM repair manual and the 1° step was check some circuits and everything was ok. The 2° step was change the ECM but i used the same MEM-CAL and i can´t connect the scanner with the new ECM. The next step would be change the MEM-CAL but before anything more, i would like to be sure that the MEM-CAL is the problem. I change the IAC and check the IAT and CTS. The sensors are ok and i don´t find any leak in the manifold. What can i do to try to solve this problem? Thanks for any help that you can give me!

Regards.

Clemente K. Sutto

 

[gmjunkie]

adHi Friends,

Well, i have a big problem here. Some weeks ago my Corvette 91 Aut 350 LT5 starts a high idle rpm ( 3188 rpm) and bad throttle reponse. I bought a Actron Scanner and try to connect with the ECM but i can´t stablish a connection. I consulted the GM repair manual and the 1° step was check some circuits and everything was ok. The 2° step was change the ECM but i used the same MEM-CAL and i can´t connect the scanner with the new ECM. The next step would be change the MEM-CAL but before anything more, i would like to be sure that the MEM-CAL is the problem. I change the IAC and check the IAT and CTS. The sensors are ok and i don´t find any leak in the manifold. What can i do to try to solve this problem? Thanks for any help that you can give me!

Regards.

Clemente K. Sutto

Check ALL Grounds!!! Especially the ones on the back of the Block!!I just had a 2 week run in with a LT1 6sp car because of the ground wires and stud that go's through the bell housing into the block just above the clutch slave cylinder!!! Symptoms were High and Erratic Idle,Random ECM,Opti,TPS,MAP,MAFS,IAC,CTS,O2,VATS and No Communication Codes!!!

 

[91vettecks]

Check ALL Grounds!!! Especially the ones on the back of the Block!!I just had a 2 week run in with a LT1 6sp car because of the ground wires and stud that go's through the bell housing into the block just above the clutch slave cylinder!!! Symptoms were High and Erratic Idle,Random ECM,Opti,TPS,MAP,MAFS,IAC,CTS,O2,VATS and No Communication Codes!!!

Hi GMJunkie!!! Well, i´ll check it right now!!! I hope that you can hit the solution for this matter!!! I would like to say thanks for your very quick reply!!! As long as i have some new i´ll tell you ok.

Best Regards.

Clemente K. Sutto

 

[89vetter]

Any solution?

Any solution?

 

[toptechx6]

Any solution?

For what it is worth I'll relate my experience with an Auto Xray 6000 scan tool made by the same company that makes Actron by the way. The 6000 is advertised to work on OBDI and OBDII vehicles so I thought it would be useful on my 93 Corvette as well as our newer daily drivers. After purchase it was tried on several vehicles and functioned perfectly on all OBDII cars tried, it would read fault codes on the Vette but would not display live data.
I contacted the manufacturer and they at first tried to convince me it was operator error, after explaining I was an ASE certified master technician they said they would send a new ALDL cable for the Corvette, it worked no better than the first one so I called them back. They then said the problem must be a bad ECM in my car even though I explained I could access all data using my Tech 1 scan tool. To satisfy my own curiosity I found another local 93 owner and asked to try the tool on his car, it did not work on his car either. After explaining this to the tech support at Auto Xray they agreed to send me a new scan tool, it did not work on the Corvette either.
At that point I again contacted tech support and explained that under the circumstances I wanted my money back since the tool would not function as advertised, they indicated they would send another new scan tool for me to try before throwing in the towel and refunding my money. Amazing as it may seem the third tool tried did indeed function correctly and has continued to do so since.
Simply pointing out that such problems may NOT be related to your car. If at all possible try the tool on an identical or simialr vehical or if that is not possible try a different scan tool to see if it will work. If you suspect the tool is not fuctioning as advertised be polite but persistant with tech support and insist they furnish what they advertise, good luck.

 

[TedC]

If your scanner allows, make sure you select the right make and model. OBDI scanners read serial data produced by the ECM, and this communication protocal requires the right settings to sync up. You cannot manually adjust these communications settings (speed, buffering, parity ...) on an autoxray (3000 or 6000). They are adjusted for you when you select make and model. Also, check for firmware upgrades. The 3000 doesn't seem to have the hit and miss sync issues like the 6000 with OBDI vinatge cars.

 

[CHRLDO]

At that point I again contacted tech support and explained that under the circumstances I wanted my money back since the tool would not function as advertised, they indicated they would send another new scan tool for me to try before throwing in the towel and refunding my money. Amazing as it may seem the third tool tried did indeed function correctly and has continued to do so since. I JUST BOUGHT A 6000 FOR A 92 VETTE. WHICH TOOL DID THEY SEND THAT WAS CORRECT?

 

[WhalePirot]

my Corvette 91 Aut 350 LT5

A ZR-1? Is that ECM different from the LT-1 and possibly incompatible with most scanners?

These e-tools are great but cannot tell you if a vacuum hose is leaky, so the basics still apply, like checking ground straps, misconnects, bad connections on electrical or vacuum lines, etc.

Checking the simple, first, saves me plenty of time.... as in 'Did I touch something recently?'

 

[Hib Halverson]

Would like to think that after more than four years ,the OP has fixed his problem

Indeed.

I'll add that LT5s did use a unique ECM, but it any scanner which is operating properly and supports the model year in question, should connect to an LT5 ECM.

On my 2G ZR1, over the years, I've connected a bunch of both pro and consumer scan testers without trouble.

 

[toptechx6]

At that point I again contacted tech support and explained that under the circumstances I wanted my money back since the tool would not function as advertised, they indicated they would send another new scan tool for me to try before throwing in the towel and refunding my money. Amazing as it may seem the third tool tried did indeed function correctly and has continued to do so since. I JUST BOUGHT A 6000 FOR A 92 VETTE. WHICH TOOL DID THEY SEND THAT WAS CORRECT?

They finally sent a 6000 that had the correct software to read the Vette data stream. Call their tech support and don't let them off the hook until they deliver a tool that works.