ahh.. that bastard 94 year...
but the best in communication protocols..
post your goodies in here for any pre-OBDII EEPROM stuff...
ahh.. that bastard 94 year...
but the best in communication protocols..
post your goodies in here for any pre-OBDII EEPROM stuff...
Business Network Solutions - for all your PC, network, printer and computer security needs.
What is up with the 94's anyway. I got a 94 Grand Prix GTP with the 3.4 DOHC, still uses the memcal but OBDII style error codes. I have tried every scan tool program under the sun aside from a GM Tech scanner, and none work.
does it have the OBDII style underdash connector?
On Cavaliers they still had the ALDL connector - but like you have.. some strange OBDII attempts at other things. It still was 8192 but it switched from a regular memcal to a flash chip (in a socket I believe).
It was kind of like OBDII but with good ol serial communications. (95 in cavs they switched the connector to the D style me thinks)
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Glad to see this board here as well. Glad to see a lot of familiar faces
I've been dynotuning and messing with the LT1 code since 1999, I keep a lot of my madness at:
http://www.carprogrammer.com/Z28/PCM/
(I really need to add an index)
Looking forward to seeing some great ideas here.
-Christian
'sup, Christian? Good to see you here. I was about to post a link to that file folder on your page.See ya beat me to it.
As for the 94 GTP question, is it:
SPECIFICATIONS FOR DATA STREAM INFORMATION
------------------------------------------
ENGINE USAGE:
3.4L SFI (LQ1) (VIN = X) 1994 1,2,3W
* 3.4L SFI (LQ1) (VIN = X) 1995 1,2,3W
If so, I have the datastream for it. It's an 8192 baud datastream (true OBDI) with OBDII trouble codes (example cut and pasted below). Wild! I've never looked at this one. Very interesting.
-Andrew
49 MALFFLG1 HISTORY MALF FLAG WORD 1
0 P0123 - TPS VOLTAGE HIGH
1 NOT USED
2 P0341 - CAM SIGNAL ERROR
3 P0321 - IC 24X SIGNAL ERROR
4 P1630 - SYSTEM VOLTAGE ERROR
5 P0117 - ENGINE COOLANT TEMP. LOW
6 P0118 - ENGINE COOLANT TEMP. HIGH
7 P0134 - HO2S ERROR
50 MALFFLG2 HISTORY MALF FLAG WORD 2
0 NOT USED
1 NOT USED
2 NOT USED
3 P1640 - QDM A ERROR
4 P0113 - IAT SENSOR HIGH
5 P0502 - VSS CKT. SIGNAL ERROR
6 P0112 - IAT SENSOR LOW
7 P0122 - TPS VOLTAGE LOW
51 MALFFLG3 HISTORY MALF FLAG WORD 3
0 P0703 - TCC BRAKE SW. ERROR
1 P0501 - VSS CKT. NO SIGNAL
2 P0755 - SSB ERROR
3 NOT USED
4 P0101 - MAF SENSOR ERROR
5 NOT USED
6 P0705 - TRANS. RANGE SW. ERROR
7 NOT USED
52 MALFFLG4 HISTORY MALF FLAG WORD 4
0 P0712 - TFT SENSOR CKT HIGH (LOW TEMP.)
1 P0713 - TFT SENSOR CKT LOW (HIGH TEMP.)
2 P0132 - HO2S SYSTEM RICH
3 P0131 - HO2S SYSTEM LEAN
4 P0325 - KS CIRCUIT ERROR
5 P1350 - IC EST BYPASS ERROR
6 P0342 - CAM SENSOR ERROR
7 P0740 - TCC ERROR
53 MALFFLG5 HISTORY MALF FLAG WORD 5
0 P1650 - QDM B ERROR
1 P1405 - EGR3 SOLENOID ERROR
2 P1404 - EGR2 SOLENOID ERROR
3 P1403 - EGR1 SOLENOID ERROR
4 P1361 - IC EST ERROR
5 P1623 - PROM ERROR
6 NOT USED
7 NOT USED
Does anybody happen to know what the deal is with the PCM in the '94 Camaro's.
I know the things have the old style connector but they have flash memory and I think (not real sure on this one) that they also use the OBD II trouble codes.
Anybody know any more?
Neither the V8 nor the V6 have any OBDII style trouble codes in them. The 1994 Y-body (vette) has a smidgen of OBDII interlaced, but the F-body is OBDI-only.
The LT1 PCM is a flash PCM, meaning you can program it "over the wire". This PCM is rather well hacked, as evidenced by Christian's web page above. I know nothing about the V6 PCM, other than the diagnostic datastream.
The 'big' diagnostic difference between the 1994 PCM and earlier years was that even though it is OBDI, it does not support flashing the SES light to extract codes. You must have some sort of interactive scan tool to get codes from it.
-Andrew
Originally Posted by RoboGeek
Nope, OBD1 connector. It has a PCM diag pin, a 'entertainment' diag pin, and ground. And this is for sure, it is still memcal: BHZW.
As far as i know the 94 and 94 3.4 LQ1 use the same PCM (16196401) and they are interchangeable. Any info you have I would really really want to look at. If you got the datastream I may be able to get EFILive V4 working with it since it is programmable. Those trouble codes do look like the ones I was talking about.
On a side note, that trouble code section you pasted looks like it came from a .bin mask definition file. If it is, do you mind sharing ;D
What I am looking for is a means to turbo my car and if at all possible keep my stock PCM, but so far I have been hitting a brick wall in the datalogging and definition file arena. I believe I can get boost to work with the MAF, but I need to know what I am changing.
Ok, thanks for the info. Glad to have that cleared up about the codes.
I'm looking specifically for info on the V6 models because I have the 3.4L V6 in mine. I've known about LT1EDIT for a while and I'd like to be able to be able to do similar things to a V6 PCM.
Yes the 94 3.4L PCM is a flashable computer (doesn't use prom chips), but it is true OBDI in the connector and computer.
The 1995 3.4L PCM is a little different though. From what I've seen it's an OBDI computer (w/ OBDI codes) yet it has an OBDII connector under the dash.
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