Astrak Posted August 17, 2006 Report Share Posted August 17, 2006 By using my fancy new FSM I have found the my I034 problem is a faulty 800 CKT in the FSM it says repair 800 CKT but does not say anything else about how to repiar it. Does anyone know how to repair 800 CKT on a 92 Eldo any help would be greatly appreciated. Link to comment Share on other sites More sharing options...
Astrak Posted August 18, 2006 Author Report Share Posted August 18, 2006 sigh....I guess nobody knows. Link to comment Share on other sites More sharing options...
Logan Posted August 18, 2006 Report Share Posted August 18, 2006 Well...we did tell you about circuit 800 and the cluster '--' blanking.... Anyway....circuit 800 is the communication line between the computers in the car. The way circuit 800 is set up....it is a loop. So...each computer has 2 circuit 800's. That way...if a circuit 800 wire gets cut open....the computers can still talk to each other. They can 'talk' either direction on the wire. It would be extremely rare....almost impossible...to have 2 opens on circuit 800 to a particular computer. That being said....it is much more likely that one of the computers is messing up....and corupting the circuit 800 signal. When this happens....the IPC will display '--' on all the data sets. Trick is...which computer? Can be: IPC PCM/ECM ABS ACP RSS DERM You can use a DVOM....and measure voltage between Pin M on the ALDL to ground. It should be 3-5 volts and fluctuating all the time.....this is the data moving around on circuit 800. Typically, if the voltage suddenly locks at either a high or low voltage...the fault is present. The DVOM will 'see' this issue before the cluster defaults to '--' issues. Maybe 45-60 seconds sooner.. The only other diagnostic aid would be to unplug each computer one at a time until the fault no longer shows up. That being said #2....The IPC is know for causing this exact issue. 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...
jfreezn Posted August 18, 2006 Report Share Posted August 18, 2006 sigh....I guess nobody knows. Three hours is hardly time enough to determine your question' fate. I don't know what a 1034 is, but each wire in your wiring diagrams is designated with a circuit number, written along side the wire on the diagram. If you look at a wiring diagram for the trouble code you have, you should be able to spot the circuit numbered 800. The wire will also have it's size and color posted by it. Good luck, Jim in Phoenix Jim in Phoenix Link to comment Share on other sites More sharing options...
Astrak Posted August 18, 2006 Author Report Share Posted August 18, 2006 sigh....I guess nobody knows. Three hours is hardly time enough to determine your question' fate. I don't know what a 1034 is, but each wire in your wiring diagrams is designated with a circuit number, written along side the wire on the diagram. If you look at a wiring diagram for the trouble code you have, you should be able to spot the circuit numbered 800. The wire will also have it's size and color posted by it. Good luck, Jim in Phoenix I know I was just looking for a quicker response because this problem is driving me up a wall and I have waited and waited(not this site) for people to help me out and no one seems to know what causes this problem. Link to comment Share on other sites More sharing options...
Logan Posted August 18, 2006 Report Share Posted August 18, 2006 sigh....I guess nobody knows. Three hours is hardly time enough to determine your question' fate. I don't know what a 1034 is, but each wire in your wiring diagrams is designated with a circuit number, written along side the wire on the diagram. If you look at a wiring diagram for the trouble code you have, you should be able to spot the circuit numbered 800. The wire will also have it's size and color posted by it. Good luck, Jim in Phoenix I know I was just looking for a quicker response because this problem is driving me up a wall and I have waited and waited(not this site) for people to help me out and no one seems to know what causes this problem. "Well...we did tell you about circuit 800 and the cluster '--' blanking.... Anyway....circuit 800 is the communication line between the computers in the car. The way circuit 800 is set up....it is a loop. So...each computer has 2 circuit 800's. That way...if a circuit 800 wire gets cut open....the computers can still talk to each other. They can 'talk' either direction on the wire. It would be extremely rare....almost impossible...to have 2 opens on circuit 800 to a particular computer. That being said....it is much more likely that one of the computers is messing up....and corupting the circuit 800 signal. When this happens....the IPC will display '--' on all the data sets. Trick is...which computer? Can be: IPC PCM/ECM ABS ACP RSS DERM You can use a DVOM....and measure voltage between Pin M on the ALDL to ground. It should be 3-5 volts and fluctuating all the time.....this is the data moving around on circuit 800. Typically, if the voltage suddenly locks at either a high or low voltage...the fault is present. The DVOM will 'see' this issue before the cluster defaults to '--' issues. Maybe 45-60 seconds sooner.. The only other diagnostic aid would be to unplug each computer one at a time until the fault no longer shows up. That being said #2....The IPC is know for causing this exact issue. -------------------- Logan Diagnostic http://www.airbagcrash.com http://www.ledfix.com http://www.logandieselusa.com" 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...
Astrak Posted August 19, 2006 Author Report Share Posted August 19, 2006 Ok I have been measuring the voltage from the ALDL connector M to ground and even during I034 there is still fluxuating voltage, so what happens to the IPC to cause this and how do I fix it? Link to comment Share on other sites More sharing options...
Logan Posted August 19, 2006 Report Share Posted August 19, 2006 Do you have the factory service manual? From the FSM. IO34 must be one of the following: "An open in the 800 circuit between the IPC and ECM/PCM and a second open in the 800 circuit between the ECM/PCM and ACP." "An open in ECM/PCM power or ground circuits (will also result in code EO/PO 52)" "A faulty ECM/PCM or PROM" Ok, that being the factory service manual....here is some more info... The odds of loosing both 800 circuits to the ECM are pretty nill. Around 1992 GM had some goofy computer wire terminals get out. Too loose on the ECM pins. Most would have been fixed by now. But something to ponder... Reman ECMs are alot cheaper then reman IPCs. You could also drop the ECM down and tap test it. Typically you should be able to find and tap on one spot everytime and get something to happen if the computer is bad ...check engine lamp comes on...stumble....stall....rpm skip...cluster failure...whatever....if the ECM is bad. 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...
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