hoodie2011

Hey guys so I've started to get this issue when starting my '98 coupe. The engine fires does its normal rev but when it goes to settle at idle it just dies. I've usually been able to get it to catch on the second start attempt usually I depress the gas pedal a little, and I'm able to drive it the rest of the commute and no issues. Get done with work and come out a few hours later and same thing over again. If I leave it for a minute or two it usually starts no problem. So I pulled codes and got P1626 H. Which is "Theft Deterrent Fuel Enable Signal Lost"

So back story on the car I just recently had the PCM go completely haywire. Had to have it towed to the local chevrolet dealer, they called and told me that the PCM was dead but that there were no more and I could probably find one for cheaper than they'd be able to. So found one off of ebay, purchased it and the guy flashed my VIN to it and tuned out the column lock. Chevy dealer installed and drove it home. This was about 2 weeks ago.

As I understand the computer is losing it signal with the security chip in the key and cutting the fuel pump because it thinks the car is being stolen. What should I do to resolve it? I really think its got something to do with the new PCM.

Cliff8928

The passkey system is solely connected to the BCM. This code is for a communication issue between the PCM and BCM.

The first place I would investigate is the star connectors.

hoodie2011

Cliff - Thanks for that file it was pretty informative. By "star connectors" are you referring to the large wire connectors at the bottom of the PCM?

Bill Curlee

Your issue is a VATS problem.. The resistor pellet in the key is NOT being read by the IGNITON SWITCH sensor OR that value isn't getting to the BCM..

Either way,, you have to resolve that issue.

Clean the resistor pellet with alcohol and or use your spare key and see if that resolves it.

You could also have a bad key chip reader inside the ignition switch. The sensor is in a can on the end of the key cylinder. To get a new sensor you have to get a brand new key cylinder and have it re-keyed to your key.

Bill

LoneStarFRC

No. They are located adjacent to the BCM itself. See post #2.



https://www.corvetteforum.com/forums...-question.html

In the pictures in the thread, the black securing tape normally found on them has already been peeled off, so unless yours have been molested at some point in the past, you'll see the black tape on them

Bill Curlee

IMHO,,,,,,,,,,,,,,,,,,,,,,,,, You do not have a serial data buss issue! Just saying..

bc

hoodie2011

Bill - I tried the spare key it fired and worked. Went back to the normal key, the problem resurfaced. Went back to the spare again and it had the same problem as the normal key.
There's no relearn procedure required when you install a new PCM is there? According to the owners manual for the 98 its equipped with Passkey. I found a relearn procedure guide that seems fairly good but it says VATs and Passkey cars don't have a relearn procedure. However Passkey II and III both do. So are we truly Passkey I? I appreciate your help!

Bill Curlee

Theres a BCM to PCM HAND SHAKE sequence that needs to be accomplished when you replace the PCM.

The VATS info is in the Key Resistance and BCM.. If there is intermittant condtivity betwen keys, you most likely have a KEY SENSOR READER issue.. The sensor is on the end of the ignition switch key cylinder. It reads (transfers) the resistance value of the key chip to the BCM.

If that sensor isnt reading the key or transfering the resistance data to the BCM,,, THERES YOUR PROBLEM!

Bill

hoodie2011

Yeah spoke with my father in law who is an electrical engineer. I've determined that my keys are 523 ohm variety with my multimeter. Looks like a bypass to ensure it is indeed the lock cylinder might be the way to go. Then once that is determined just order a new AC Delco. Do you have any experience getting a lock cylinder rekeyed? Seems like it would be much more complicated than just cutting a new key.

Bill Curlee

Its pretty simple but takes some time... Order a new lock cylinder. Take the NEW LOCK CYLINDER along with the old lock cylinder to a locksmith. Ask him to re key your NEW lock cylinder to your old OEM KEY/lock cylinder. DONE! Simple as that!

LoneStarFRC

They can usually do it while you wait.

hoodie2011

Hey Bill and Lonestar this thread shows what the Locksmith ended up doing to fix the lock cylinder. Just wanted to show you guys in case you ever run up against the issue! Thanks for your help!

https://www.corvetteforum.com/forums...post1590226376

CactusCat

Couple of years ago I had some key issues with my 98. Same problems as others have had and I ended up doing BC's ignition switch mod (cleaning the contacts inside the switch). That seemed to help considerably but still noticed that I could simply pull the key out while the engine was running. My lock cylinder was worn badly (by all the ins/outs I guess) and needed a new cylinder. I spoke to my local locksmith and she (that's right, a gal) said to bring it by. I brought the ignition switch to her and in less than 15 minutes, she took my cylinder out, disassembled it, rebuild the cylinder with new locking keys and springs, cut me a new key that matched my old one and put it all back together for $20. Have not had an issue since. In essence, with me doing BC's mod and her rebuild of the cylinder lock, I've got another 15 years before I have to mess with this again !!!

Cliff8928

It's amazing how inaccurate the service manual is for this code. I could imagine how much it would cost to have the dealer to fix this if that's all they had to go off of.