Prop_Washer2 Posted June 12, 2004 Report Share Posted June 12, 2004 '92 Seville STS, 4.9L, 147k miles, I have a random, intermittent quirk, which seems to be associated with the A/C or HVAC Computer. Defroster kicks into high, all other button controls associated with that are "locked out" Off, Auto, Econ, etc... also the outside air temp read out, inside temp set, avg mpg, miles to go, and on the information readout below the tach/speedo, the "coolant temp" read "-----", the "voltage" and "oil life index" read normal readouts. It is truly a random occurancebut seems to be more prevelant when outside temp is above 88 to 90. IF I can fool the system by immediately putting it into "Auto" A/C mode, and IF the system catches, compressor start etc...it seems it will stay there all day. Right now I just took a 40 mile drive, I couldn't fool it at start up, so the defroster kicked in, (nice hot air off the windshield Thank You), and drove 20 miles, shut it down for an hour, did the same thing coming back home. About 1 mile from home at a stop light, the A/C kicked in, and all readouts went to normal for 30 seconds, then it went back into "defroster mode" for 15 seconds lost the readouts, then it jumped back into normal A/C mode and the readouts returned once again before the light changed. Stayed that way until I pulled into the driveway. I am sure it's a computer failing or a corroded connector somewhere. If someone could tell me where to start looking, I will start pulling panels. Fuses, etc... are all good. I can pull a fuse from under the hood, A/C blower or something, and it kills the system, but also kills the self leveling suspension. Turns into a "low rider" after a few days. Actually looks pretty good slammed !!! Anyway, this appears to be the last issue I have with this little Seville, she runs great otherwise, it should after all of you guys helping me. NOTE: I was just digging around the Firewall area, I found 2 electrical plugs disconnected, I doubt if they are related to the above, but one has (flat plug) 3 wires, b;k/wht, red/wht, (16 guage) and a Blue (18 guage) Plug says P.E.D. on it, It is near the heater core area. I see no place to plug it into. Second one is near the blower motor on firewall slightly offcenter towards passenger side. It has 7 wire holes with 5 wires. Also says P.E.D. on it. Also a wide flat plug..reading from left to right from the rear of the connector plu, there is a b;k/wht, red/wht, blk, green, skip a hole, yellow (PED marked below wire), then skip a hole. I just wonder what these are for. My Clymer (Sucks) Wiring Diagram doesn't show these. Any idea what they could be? The Seville has all options, including Sunroof, etc...I cannot find a recepticle anywhere in the vicinity that would accept these male type connectors, just curious.... Link to comment Share on other sites More sharing options...
Logan Posted June 12, 2004 Report Share Posted June 12, 2004 Its either a bad IPC/cluster or one of the computers on the UART circuit 800 has gone bad. All the computers 'talk' to each other on circuit 800. When one of them goes bad you get a bunch of 'loss of data' codes and get '--' on the display. The computers on the loop are: DERM ECM/PCM RSS ACP ABS I bet if you check the codes you will have a bunch of 'loss of data.' The hard part will be figuring out which one it is.... Logan Diagnostic LLC www.airbagcrash.com www.logandieselusa.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
98Concours Posted June 12, 2004 Report Share Posted June 12, 2004 yes, check your codes and post back! Jeff Jeff 98 Concours 90 Seville 04 Corvette Link to comment Share on other sites More sharing options...
Prop_Washer2 Posted June 12, 2004 Author Report Share Posted June 12, 2004 Here are the codes; IO33 Current IO34 Current IO37 " IO39 History IO52 History No ACP No SIR ECM? TPC? APC? SIR? Link to comment Share on other sites More sharing options...
98Concours Posted June 12, 2004 Report Share Posted June 12, 2004 I033: Loss of Supplemental Inflatable Restraint Data I034: Loss of Powertrain Control Module Data I cant find these in my service manual, but looks like a bad Computer to me. Jeff Jeff 98 Concours 90 Seville 04 Corvette Link to comment Share on other sites More sharing options...
Prop_Washer2 Posted June 12, 2004 Author Report Share Posted June 12, 2004 I'll try and find that one behind the glove box you mentioned..any other recomendations? Link to comment Share on other sites More sharing options...
Logan Posted June 12, 2004 Report Share Posted June 12, 2004 Those are the 'loss of data' codes I was talking about. The IO codes are for the IPC /cluster. They are in the cluster section of the factory service manual. Exactly like I said, one of the computers has gone bad. Finding the bad one can be very time consuming. Intermitant ones even more so.... Logan Diagnostic LLC www.airbagcrash.com www.logandieselusa.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
98Concours Posted June 13, 2004 Report Share Posted June 13, 2004 The most I can find in my Service Manual for the 90Seville is code B334, which is what I think I had. Anyway, it's Loss of ECM data. If i'm not mistaken, ECM and BCM are the same computer??? Since you got an I034: Loss of PCM Data, I'll give you what my book says for loss of ECM data: * an open in CKT 800 between teh ECM and programmer and a second open between the ECM and the CCDIC. *A faulty ECM or ECM MEM-CAL. In my case, after checking grounds and ckt 800, it led me to a faulty ECM. I get confused but think ECM and BCM are the same, and maybe at a later date like 91-92, they changed it to PCM??? During the time the failure is present, a fail soft value equal to 100C will be used for the coolant temperature, the cooling fans will be commanded to high speed, and no ECM diagnostic information will be available for display. Also, while in the sevice diagnostic mode, this code will remain active, always checking for proper operation. I think I've totally confused myself, how about you? Jeff Jeff 98 Concours 90 Seville 04 Corvette Link to comment Share on other sites More sharing options...
Ranger Posted June 13, 2004 Report Share Posted June 13, 2004 ECM is "engine control module" and has been changed to PCM "powrtrain control module". BCM is "body control module" and has been changed to PZM (I forget what that stands for). platform zomething module Link to comment Share on other sites More sharing options...
98Concours Posted June 13, 2004 Report Share Posted June 13, 2004 That makes sense. My B334 would be the same as Prop's I034. So, back on track prop. Jeff Jeff 98 Concours 90 Seville 04 Corvette Link to comment Share on other sites More sharing options...
Prop_Washer2 Posted June 13, 2004 Author Report Share Posted June 13, 2004 As far as getting confused, I am getting there hehe, but I think I got it... Anyone got any ideas on those two loose plugs I mentioned in the original post... ??? They puzzle me... Link to comment Share on other sites More sharing options...
98Concours Posted June 13, 2004 Report Share Posted June 13, 2004 I'd check all grounds and make sure the wire harnesses are plugged into the computer tight. Then, start looking on ebay for a Helms factory service manual....it will give you step by step troubleshooting trees. Don't know anything about those two loose plugs. hmmmmm Jeff Jeff 98 Concours 90 Seville 04 Corvette Link to comment Share on other sites More sharing options...
Logan Posted June 13, 2004 Report Share Posted June 13, 2004 The 1990 service information will not apply to the 1992. Completly different car and computers. The IPC on the '92 IS the body computer. He has mutiple 'loss of data' codes. These means the data on the data line is corrupt. He needs the factory service manual. Logan Diagnostic LLC www.airbagcrash.com www.logandieselusa.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
Prop_Washer2 Posted June 21, 2004 Author Report Share Posted June 21, 2004 I found the PCM behind the glove box. I wiggled both connectors around, they sem to be real tight. I tried to pull them off to look at the actual connections, squeezed the release clips, but still couldn't get 'em off. I'll try again just to see if they are clean. The outside of the connector looks good though. It appears that the system wants to go to 75 degree, defroster mode now a little more often, even if I get into A/C mode first...Hot air blowing onto the winshield is real fun in 100 degree weather...I found another site with A/C stuff in general, and there is a condition there, "Code 5" referencing the BCM, that puts the defroster in to 75 degree mode....hmmm sounds like my problem. I think they have a phone number...I'll call 'em and see wassuupp... Link to comment Share on other sites More sharing options...
careldo Posted June 21, 2004 Report Share Posted June 21, 2004 What you are experiencing is the default mode the ECM is commading when the serial data is corrupted.Get the factory manual to properly diagnose the problem. My guess is your IPC is failing. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.