Redi2RocZ

Help Guys!

Please can anybody tell me the correct PROM/ECM numbers for my car?

305Tpi with 3.23 Axle GU5, G80 Positraction & G92 Performance Ratio with QDZ 245/50/16 Tires?

The above are on the RPO codes as printed on the Tag in my car.

The ECM fitted to my car is going bad I (think) - Part Number 1227165

Is the Part Number, 16198259, a direct & correct supersision for 1227165?

I have a new PROM with number 16059000 but I believe it should be 1228291. Will these two PROM's interchange? Is the 16059000 a supersision for 1228291 or do I need this PROM?

Any info would be very much appreciated

Thanks in anticipation

Grim Reaper

Yes, the 8259 is a replacement ECM for the 7165 - so the ECM is fine.

As for the Memcal, we go by Broad Cast Codes. Every eprom has a 3 or 4 Alpha code followed by a 4 digit number. There are a TON of Memcals that could possibly work - some are original, some are replacement.

But we need the BCC first. The BCC is found on the silver tag under the light blue cover of the Memcal that covers the Eprom Window. Look for the "AAAA 9999" BCC on that silver tag and give it to us, and we can tell you if that is a valid eprom.

Redi2RocZ

Thanks for your reply, very much appreciated -

Glad the ECM checks out.

The original PROM has the following numbers & letters on the Silver Label AUM 3236 and under the label on the chip 014P 5DBB 69300 AA8643B

The new replacement PROM has the following numbers & letters on the Silver Label AWD16059000 and under the label on the chip 014 69300 B9818AF

Hope that these codes are what you need to help me out.

Thanks very much

-

Grim Reaper

The AUM 3236 (part# 01228291) was released on 9/17/86.

The AWD 9004 (part# 16059000) was released 7/18/85. So the AUM is a more current version.

However, what bothers me about the AWD is that it is for 3.42 rear axles, even though it also specifies an automatic transmission.

This bothers me a lot because I do not believe that you could get an auto with 3.42 rear axle AND 305 TPI.

Your AUM should work fine and strikes me as being preferable. As for the specific differences between the two, you would have to run a "binary compare" to identify ALL of the differences to see what it should be.

Grim Reaper

I did a quick check on the two bins and there are a fair number of differences between the two.

Basically, the AWD looks like it can set an error code much easier than the AUM. Possibly the AWD was specifically for California cars and the AUM is 49 state.

I don't have time to analyze all the differences, but if I had to chose between the two, I would go with the AUM (newer code and greater "forgiveness" in setting error codes, especially 32).

Better yet, dump the cold start injector and go to the ARAP or a 1989 Memcal. They were the best calibrations.

Redi2RocZ

Glen,

You have answered my question with more info than I could have imagined!!

I will be getting the 1228291 PROM and the 16198259 ECM asap.

Hopefully doing this will cure my crazy Tpi!!

Thanks for your help and assistance in this matter.

A truly excellent site with a vast amount of tech info from a lot of knowledgeable people.

raptoryfm660r

I know my Z 28 runs better with the 1228291 PROM. I installed in my car on 8-18-89 with 1870 miles on it at that date. I paid $40.26.
The prom that was installed at the factory is coded on the foil as AMU 8958.

I found this new prom number out by another 1986 Z 28 owner with the 5.0L TPI engine back in the summer of 1989. His car was having the check engine light come on a lot and took it in and the dealership had a service bulletin that addressed some of the codes that his car was displaying. They installed 1228290 prom in his Z 28 since his car had air conditioning and the P215/65 R 15 wheels & tires. He told me his car even run better than it had with the old Calibrator. He gave me a photocopy of the service bulletin dated 10/17/86. I had some of the cold start problems but the main thing I didn't like with the old calibrator was that when you took off and it went through the gears so fast and you were in overdrive by the time you hit 25 mph. I found myself when I was driving around town just putting the selector in 3rd gear.
With the new 1228291 for my air conditioned, P245/50 VR16 tire its almost 45 mph before the car goes into overdrive.

With this service bulletin it eliminates the following false codes. 32, 33, 34, 43, 44.

With the old calibrator or new one the check engine light has not come on yet in my car.

I would recommend this prom for any 1986 5.0L TPI engine. There is different part numbers though that have to deal with the tire size or if the car had air conditioning or not.

Chet

Redi2RocZ

Managed to resolve my Tpi problems way back in Nov '01 with the problem turning out to be a faulty ECM!

Bought a used ECM via eBay from www.chevythunder.com - Great Web Site.

Anyway, I have since fitted the updated Calibrator and the engine runs much sweeter.