GM Guy Posted December 29, 2013 Report Posted December 29, 2013 Hey guys and Happy Holidays! My 95 GP w the 3100 and OBD 1.5 is getting a bit long in the tooth after 277k and was looking to find out if anyone has done a backwards swap to OBD 1 lq1 and problems. Would be using my 91 Z. My GP doesn't appear to have a pressure sensor which is used for idle on the lq1. Also does the swap affect the anti theft and key/chip? Quote
l67ss Posted December 29, 2013 Report Posted December 29, 2013 95s were obd1, not obd1.5. You need to get c100 color codes as they tended to change a bit. If they are diff, theyre not hard to modify. Took me ten minutes on mine including wrapping my whole harness in electric tape. Good luck Hey guys and Happy Holidays! My 95 GP w the 3100 and OBD 1.5 is getting a bit long in the tooth after 277k and was looking to find out if anyone has done a backwards swap to OBD 1 lq1 and problems. Would be using my 91 Z. My GP doesn't appear to have a pressure sensor which is used for idle on the lq1. Also does the swap affect the anti theft and key/chip? Quote
RobertISaar Posted December 29, 2013 Report Posted December 29, 2013 i more or less did this exact swap in..... 2009? there are a few ways to go about it, from making an adapter harness at the PCM connectors to swapping the entire underhood harness. Quote
GP1138 Posted December 29, 2013 Report Posted December 29, 2013 95s were obd1, not obd1.5. No... 95 LQ1's were OBD1.5. Quote
RobertISaar Posted December 29, 2013 Report Posted December 29, 2013 depends on how you define "1.5". Quote
19Cutlass94 Posted December 29, 2013 Report Posted December 29, 2013 x2. by definition there is no 'obd1.5' but 94-95 cars have been dubbed that due to their 'special' needs lets call it But Saar made me an adapter harness by the PCM. Been working great since day 1. How many yrs ago was that! Quote
GP1138 Posted December 30, 2013 Report Posted December 30, 2013 It's different enough from OBD 1 to be called 1.5, I think. Quote
RobertISaar Posted December 30, 2013 Report Posted December 30, 2013 depends on what you qualify as 1 vs 1.5. a lot of 94-95 cars randomly got the 16 vs 12 pin connector, you could have two otherwise identical cars/PCMs, just the different connector, so i can't recommend that being used as a determining factor. 94-95 LQ1(and A-body L82) used OBD2-style DTC descriptions, but the PCMs themselves were little more than slightly modified 93-earlier 3800 PCMs. 93-95 L82 used OBD1-style DTC descritions, but the PCMs were fairly unique, sharing a lot of design similarity to the 94-95 LT1 and 93-95 Northstar units. also used a pair of flash PROMs. Quote
Nas Escobar Posted December 30, 2013 Report Posted December 30, 2013 depends on what you qualify as 1 vs 1.5. a lot of 94-95 cars randomly got the 16 vs 12 pin connector, you could have two otherwise identical cars/PCMs, just the different connector, so i can't recommend that being used as a determining factor. 94-95 LQ1(and A-body L82) used OBD2-style DTC descriptions, but the PCMs themselves were little more than slightly modified 93-earlier 3800 PCMs. 93-95 L82 used OBD1-style DTC descritions, but the PCMs were fairly unique, sharing a lot of design similarity to the 94-95 LT1 and 93-95 Northstar units. also used a pair of flash PROMs. While on that subject, what scanner would you use on a 94-95 LQ1 car? I know the paper clip trick doesn't work on it, so which scanner will work on these cars? Would it be the same as the LT1 Camaro's plug? Quote
Galaxie500XL Posted December 30, 2013 Report Posted December 30, 2013 (edited) I use an ancient Actron CP-9110 on my '95 LQ1, it seems to work well..but you'll need a GM cartridge, and cable, which may or may not come with the scanner. I lucked out, and mine did. Paid $80.00, I think on Ebay for it several years ago. EDIT: There's one on Ebay right now, but it has a Chrysler cartridge, so you'd need to buy a GM cartridge with the GM ALDL cable to make it work on your LQ1. http://www.ebay.com/itm/Actron-111-Diagnostic-Tool-ScanTool-Model-CP9110-w-Chrysler-Software-Cartridge-/181264522317?pt=Motors_Automotive_Tools&hash=item2a34351c4d Edited December 30, 2013 by Galaxie500XL Quote
l67ss Posted December 30, 2013 Report Posted December 30, 2013 Personally id convert everything i get to obd2 if i can. I view obd1 like a benign brain tumor, sure you can live with it but its still a damn headache. You never hear of people having trouble scanning obd2. Just my $0.02. Quote
Nas Escobar Posted December 30, 2013 Report Posted December 30, 2013 I use an ancient Actron CP-9110 on my '95 LQ1, it seems to work well..but you'll need a GM cartridge, and cable, which may or may not come with the scanner. I lucked out, and mine did. Paid $80.00, I think on Ebay for it several years ago. EDIT: There's one on Ebay right now, but it has a Chrysler cartridge, so you'd need to buy a GM cartridge with the GM ALDL cable to make it work on your LQ1. http://www.ebay.com/itm/Actron-111-Diagnostic-Tool-ScanTool-Model-CP9110-w-Chrysler-Software-Cartridge-/181264522317?pt=Motors_Automotive_Tools&hash=item2a34351c4d I've seen that floating around for a while, but I haven't seen the Cartridge for GM come up. Quote
Galaxie500XL Posted December 30, 2013 Report Posted December 30, 2013 IIRC, the Actron part number for the GM cartridge is CP9111. A new one will have both the cartridge, and the cable...you'll need both. Quote
Galaxie500XL Posted December 30, 2013 Report Posted December 30, 2013 I think I found one... http://www.ebay.com/itm/Actron-All-GM-Saturn-1984-1995-Scan-Cartridge-/170379594634?pt=Motors_Automotive_Tools&hash=item27ab6a4b8a&vxp=mtr Quote
95LQ1VERT Posted December 30, 2013 Report Posted December 30, 2013 Speaking of the devil, I just listed mine! I'll sell it for $115 with everything needed! Sent from my HTC One V using Tapatalk Quote
GM Guy Posted December 31, 2013 Author Report Posted December 31, 2013 (edited) My 95 with the 3100 is definitely the 1.5 and hasn't changed magically since we got it new. No one around here has the scanner/cable to hook it up and the part store guys used to look at me strange when the 1 or 2 wouldn't fit after I repeatedly told them. No doubt special needs. Also it was hit/miss across the GM lineup for late 1994, most 95s got 1.5 unless they still had parts on the shelf. Big upside to 1/1.5 is no MAF to go bad. Downsides are obvious. Edited December 31, 2013 by GM Guy Quote
RobertISaar Posted December 31, 2013 Report Posted December 31, 2013 with any 94-95 W-body, you'll either have a 12 pin(like everything else GM OBD1 from ~1984-upwards) or 16 pin OBD2 connector. the PCM communicates using the OBD1 8192 baud protocol, so any scanner that reads actual serial data and not just flash the SES should work. i see no real downside to the OBD1 PCMs, especially once you start writing custom code that surpasses the capabilities of most common OBD2 PCMs. Quote
Imp558 Posted December 31, 2013 Report Posted December 31, 2013 Personally id convert everything i get to obd2 if i can. I view obd1 like a benign brain tumor, sure you can live with it but its still a damn headache. You never hear of people having trouble scanning obd2. Just my $0.02. I agree, such a PITA to troubleshoot. Maybe yet another L67 swap on the horizon? lol Quote
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