I just bought my first Vette six days ago, a 1990 convertible/6 speed. I got it super cheap because it is non-operational. The guy I bought it from purchased it five years ago and parked it in his garage for the winter. He would go out and start it once a month. He soon forgot to do it and when he remembered, the battery was dead. He charged the battery but the car would not start. So, he replaced the ECM, still would not start, not even turn over. He then replaced the CCM, still would not turn over. He then installed a VATS by-pass chip and installed in the ECM, same results. In the process of doing this, he totally dismantled the dash. I now have the car at the local Chevy Dealership to have the CCM programmed to the ignition key. They don't have a diagnostic tool to communicate with the car and I have lost faith that they can fix it so I will probably bring the car home tomorrow. What can I do to fix this problem? I have no experience with VATS other than some recent research. Thanks in advance for the help.

 

They need nothing other than a VATS interrogator to accomplish the "crank" after the starter circuit is confirmed operational. Was the CCM the PO bought a used or new unit? If it was new then the CCM I believe would have learned the key (1 time only), the VIN would have needed to be entered and the mileage set within I believe the first 100 miles or maybe is 150 or it would become locked to the miles displayed.

The VATS learn procedure is done using only a key (or as many as 3), the ignition cylinder and the security light on the dash if the CCM is new. If the CCM is used then the VATS interrogator would need to be used to find the resistance that will allow the crank, then a new mechanical cut needs done on the appropriate key with a matching resistance.

The VATS that was done as you hint to the ECM was likely a reprogram of the PROM and that would have only been for the "fuel enable" of the VATS not the crank. Once home you need to confirm the integrity of the entire crank circuit in including starter enable relays, etc. How was the VATS disabled other than the ECM? Check to see that the ignition cylinder is still connected to the car harness for the ignition cylinder VATS.

Make sure this connection is complete at the column base:

http://forums.corvetteforum.com/1557847121-post4.html

If you want to give the shop one last chance at it have them read the CCM with a tech1 and ask if the VIN and the mileage are displayed. Check the VIN to the car and the miles to your title. If the VIN is a match and the miles a match the CCM has been programmed. If they're not a match all is not lost. You need to establish the resistance that's in the used CCM by using the VATS interrogator as I mentioned. How much have they charged you?

Where are you located?

 

I will see the previous owner tomorrow morning and will ask if the CCM was used or new. I believe it was used because the P.O. said it had 65,000 original miles before he put in the different CCM but now shows 76,000. I know that he had not driven the car since he installed the CCM because it has never started. They said they would not charge me more than $98 without calling me and telling me it will cost more. I really would like for them to get it running, the problem is, they are a well known Chevy dealership in business for more than sixty years and they don't know anything about a VATS Interragator or a Tech1. They told me they don't have a diagnostic tool to plug into they car to communicate with it. I feel like I would be better off buying a new CCM and installing it myself. I followed the book in trying to program the CCM with the original key but when I remove the key the security light just keeps flashing and there is no prompt to reinstall the key. Thanks

 

I am located in Junction City, OR

 

That only removes the requirement for the fuel enable signal to the CCM , you still have to manually bypass the VATS operated starter enable relay under the dash for that chip to be functional and VATS completely gone.

If that bypass is done and as noted above the starter circuit is actually working then the engine should crank and start regardless of what CCM is installed ( or not ).

You can test functionality of the delete chip by hot wiring (a push button ) the stater motor; key on the engine should fire when the engine is cranked over on the starter.This of course is dependent upon all the other engine (fuel , etc ) systems working as they should

 

the interesting thing is, the P.O. said he could start the car by squirting gas in while he jumped the starter solenoid and it would run as long as he squirted gas in. That tells me that the chip in the ECM did not re-energize the fuel pump. May need a new fuel pump relay?

 

There are no new CCM's. Since we've determined that the CCM is used do you have maybe the original also? Maybe ask the PO also.

There's a good bit of material to remove to get to the CCM. Is the DERM (orange brick) still in the car for the air bag system? The car won't crank if there's a problem with the SIR/DERM, a blown air bag fuse can defeat crank also.

Do you have a key that actually rotates the ignition cylinder?

Ask the dealer if they have a VATS interrogator, a call to the parts dept would answer that question. Ask the parts dept if they have this part number GM # 26007687. If they don't call other GM dealers that are near you or ask the dealer the car is at to check their locater for you. If they don't a lock-smith would have one just ask for a "work key"!

That part number is a VATS work key that has no resistance. With that key and a VATS interrogator if the starter enable relay is good then a correct code for the CCM should be able to be determined.

NOW - the car is an M6 so there's a clutch safety switch that needs to function correctly OR could be bypassed to get to a crank.

Check for the work key, ask the parts dept if they have a VATS interrogator and let's see what happens. I can understand you'd like for the fix to be accomplished where the car is rather than have to do another tow.

DO the leg work before a conversation with the service dept, there's something that just doesn't seem right with the way you've either interpreted what they told you (I doubt that - you've explained pretty well) or the information passed to the service writer is flawed.

 

Yes, I have the original CCM. I reinstalled it a few days ago and there were quite a few things on the instrument panel that did not light up or work, so it appears the original CCM is in fact bad. All instrumentation works with the new CCM. I do have the original key that does rotate the ignition cylinder. I cleaned and sorted all the parts and pieces to the dash but did not put the dash back together so it would be easy to access everything in the diagnostic faze of this repair. I actually spoke to the service writer and the mechanic doing the work. The mechanic said he would research the issue over the weekend and come up with a battle plan. I love the car and plan on keeping it for a long time. Thanks for all the help, I am learning a lot about my car.

 

They said they no longer have the Tech1 and they do not have a VATS Interrogator. The mechanic is going to go through the fifteen key sequence, try one and wait five minutes, try the next one and wait five minutes, etc. I hope it works but am wishing I would have just kept the car in my shop and did it all myself.

 

If it requires fuel to be sprayed in to keep running then that indicates the injectors are not being fired and that the "VATS delete" chip is not doing it's job

FWIW
The ECM only runs the pump for 2 seconds ; key ,on to build pressure then it turns it off until it sees the engine being cranked over
In any case the engine should start with extended cranking because the oil pressure switch ( if working ) will operate the pump independent from the relay once the engine OP is above 4 psi;if the ECM fires the injectors.

 

For starters there's NOT a 15 key sequence for a '90. That was a one year only thing and there's 2 - 15. How does he intend to do that? Did you get a work key done? The other solution that would work is take one of the keys that actually rotates the cylinder and knock the resistance chip out of it. It is now effectively a work key and since you're using the 2nd CCM the keys are trash anyway. DO NOT discard the CCM.

I understand the "wish it were home" and under your own control. I'd approach it in this fashion maybe, MAYBE! Is there another GM dealer in the vicinity? If yes suggest that the service manager maybe acquire their Interrogator to accomplish the task.

Were the SIR fuses etc checked after I mentioned those?

 

I went to lunch with one of the service managers today and we talked about this problem. He said they do in fact have a VATS Interrogator but there is no reason to use it because they are unable to communicate with the car. He said it appears everything was erased when the used CCM was installed by the PO. It may come down to buying a new rebuilt CCM and go from there. He said the mechanic is well qualified and will fix this car. I hope so, I will check with them early tomorrow afternoon. Yes, there is another GM Dealer within 15 miles of here. Thanks for the help and suggestions.

 

The PO told you that the mileage display is greater than that of the original! That so to speak is contradictory to the shops comments of not being able to communicate with the CCM. If the tech mentioned he would attempt all resistance values what are his intentions for doing that? The VATS Interrogator! If the CCM is installed and the key rotated to the "KEY ON" position do you have gauges, lights etc? Does the SECUITY light go solid, flash or do nothing? I believe that if you can get to "KEY ON" and the DIC module is in the car or could be plugged into the car the CCM information can be accessed from the DIC. Here's the procedure in pretty simple terms:

http://tech.corvettecentral.com/2011...trouble-codes/

You don't want to buy a reman CCM for sure NOT YET and that's a reason why I asked if you had the old one. To replace the CCM if a reman is used a Tech1 is going to be required to set the VIN and also the miles. I don't believe that can be accomplished by a Tech2, I of course could be wrong but the CCM's I've had anything to do with were done with a Tech1. It's good that you mention all and it's needed to be understood that the car is an M6 and the clutch safety switch requirement is there, for Interrogator operation I believe it's easier by-passed rather than "foot operated" at each key attempt BUT the shop might need to be advised that it's there.

It's quite an "adventure" you've gotten yourself into! You've got the correct "mind-set" for a dealership experience and that's "conversation". Developing an attitude can certainly create issues.

 

I acquired the car with an ECM and a CCM replaced by the PO. The ones he removed came with the car. When I turned the key to the on position, the odometer reads 76K but the oil change receipt the PO got on his way home with the car 5 years ago shows 65K or 66K. The security light comes on when the key is in the on position and flashes for a while after the key is turned to the off position. The mechanic and the service manager has different stories. This morning I asked the mechanic to use the VATS Interrogator to find the resistance code in the CCM and he said they don't have one, the service manager said they do in fact have one. I told the mechanic he needs a Tech1 for my car and he said they no longer have one, the service manager said they have all of that. He tried to reassure me that my car was in good hands, but I have to say that I am a little more than skeptical. I explained to the mechanic that the CCM is a used one with unknown key resistance values and a VATS Interrogator must be used to find that. He said he can do the same thing through trial and error with all the keys. I am giving them until tomorrow afternoon than I must bring the car home. That will be three days for what appears to be a pretty simple fix. Thanks

 

It's likely not simple but I understand the frustration. You need to consider that most of the line technicians that are actually familiar with the late '80s and early '90s technology have either moved on to management, retired or maybe if they're fortunate not involved in the current automotive repair field.

For the technician to be able to use 14 keys first of all the parts department needs to have all 14 and I'll wager if asked they don't. The parts inventories are sales generated and I'd guess they may have 3 - 5 of them. Next he's got to convince someone to let him open 14 packages that contain an application specific key. What were his intentions for crank? He could plug a new cylinder into the connector under the dash and inserting the new keys one at a time would satisfy the resistance requirement but that just emulates the Interrogator, he's got to convince someone now to let him use another new part to accomplish that. The tech didn't plan on cutting all 14 keys maybe?

 

I just spoke to the mechanic, an older guy, Electrical Engineer by trade but doing what he enjoys now. He is actually a pretty nice guy. Said he was no further along and said trying the keys did nothing. I looked under the steering column and pointed out to him that the key cylinder pigtail was unplugged. I could see that the PO had cut the pigtail and then re-taped it, obviously had tried to bypass the key resister pellet. In further conversation with the mechanic, he said they do have a Tech1 but it is broken and they are obsolete, can't find another one. He is checking out the entire wiring harness that has anything to do with the ECM and CCM using a wiring schematic. He seems to think there may be a broken wire or bad connection somewhere that doesn't allow the CCM to communicate with the ECM. He wants to put the original CCM back in and try it. I told him I thought I would take the car back home and he said he would really like to fix the car but he would charge me nothing because he has fixed nothing. I showed him how to take out the CCM and told him I would check back with him tomorrow.

 

WVZR-1, I have a question for you. Lets say that my CCM is good and my ECM is good. The ECM has the VATS bypass chip. If I were to take a new starter relay and take it apart and solder a jumper in it, would that completely bypass the VATS system? If I did that and it still doesn't crank and start, wouldn't show that either my ECM or CCM is bad? Been reading other threads and this seems simple enough.

 

I'd quit screwing with VATS bypasses and ECMs, etc. Put the original ECM and CCM back in. Ensure you have the original key. Ensure the wiring is in working order. Now begin trouble-shooting.

If the POs story is true, I'd almost be willing to guess that the fuel pump went bad. When you turn the key to "run", you should see 12v at the pump and you should hear it run for 2 seconds.

 

To answer directly your first question regarding the relay. I don't believe that doing that by itself would be a good indicator of a bad ECM or CCM.

Do you have two PROMS (chip) or did the PO have the original one reprogrammed supposedly for the VATS by-pass? If the programming was done by a "novice" the fuel enable aspect could be all messed up. You mention the harness under the dash is "re-taped". If you insert a known value key in the cylinder can you read that value at the column base?

Remove the cover of the ECM over the chip and there will be two small windows in the PROM. You should be able to read information in one of those windows that would indicate it being OE/GM. Is there any inked marker information on it?

I believe if you confirm the state of the clutch switch, confirm that the cylinder reads a correct value at the column base plug in the original CCM and do a key check and see what happens. So to speak starting over. At that point if the starter enable relay were by-passed I'd think you should be able to establish crank. I've pointed you to diagnostics that can be done using the DIC why not start with the original CCM and move forward.

With the car home you could certainly establish a plan and very methodically work through it. It seems you've got a grip on the understanding and looking over the shoulders is beginning to frustrate you.

It seems Jim somewhat agrees with the start over!

 

If you were to pull the codes as WVZR-1 suggested above , possible you have DTC 41 present ; a common communication ( wiring ) problem between a working ECM and a working CCM.
A very frustrating , and sometimes labor intensive problem to troubleshoot
http://forums.corvetteforum.com/1554492041-post15.html
http://www.digitalcorvettes.com/foru...5&postcount=17

read post # 10

Read post # 5
A wire from the battery to the starter solenoid will perform the test.

If it didn't crank you have a problem with the starter circuit components , wiring or starter motor
If it cranks but does not fire then it is a fuel enable (ECM ) problem