climate and info center problem

rayj · #1 (**permalink**) 08-03-08, 07:13 PM

i just purchased a 1992 eldorado and it has the following problem, the climate control and infocerter to the left and right of the speedo will light up when the car is first started and everything looks normal then between 15 and 30 secs later all info goes to dashes and the heater turns on heat and high fan. what should i look at first?
any help would be great
Thanks Ray

CadillacSTS2003 · #2 (**permalink**) 08-03-08, 07:29 PM

did you run diagnostics...

rayj · #3 (**permalink**) 08-03-08, 08:25 PM

yes i did here are the codes it returned, IO33, IO34, IO37, IO39, IO52, no ACP data, no SIR data, AO37, RO61, ECM?

i think i got those all in that order

carnut · #4 (**permalink**) 08-03-08, 08:47 PM

I would investigate all engine grounds, cable at battery and ground wires secured to engine block. no data means an open, incomplete circuit.

rayj · #5 (**permalink**) 08-03-08, 08:59 PM

ok i can check that out ond even run an additional ground to the body from the battery, i was thinking it may be a ground problem. are there any grounds inside the vehicle i should check out?

carnut · #6 (**permalink**) 08-03-08, 09:37 PM

If you are going to add a ground, add it from the engine to the frame. Should be engine grounds by the starter on a stud.

rayj · #7 (**permalink**) 08-03-08, 09:46 PM

i will check the grounds tomorrow. i was going to add a ground from the batt to the body and from the batt to the engine, should i also add one fron the block to the frame?

Logandiagnostic · #8 (**permalink**) 08-04-08, 08:32 PM

All those code show loss of data on the tan 800 circuit. All the modules are wired on a communication loop. If one of the modules go bad, you start getting the '--' data and the defroster comes on.

You can measure the voltage of circuit 800 on pin M on the ALDL. Should be 1-5 volts and always flucuating. When 'the' module goes bad, the voltage on pin M will lock up, about 15 seconds latter the IPC will start messing up.

My '93 had the same problem. Mine was a bad IPC.

The data would go '--' and the defroster would engage.

Reman IPC's are about $300 exchange at Delco radio/speedometer repair shops. With you walking in the IPC.

There is a problem with the Delco shops. Normal test mode for them IS '--'. So it's very hard for them to locate this fault. So in some cases, it takes 3-4 'reman' IPC's to find a good one.

You can also try unplugging the modules one at a time, and see if the fault goes away.

Logan Diagnostic LLC
www.ledfix.com
www.airbagcrash.com
www.logandieselusa.com

rayj · #9 (**permalink**) 08-04-08, 08:46 PM

i can measure the voltage so where do i find "circuit 800 on pin M on the ALDL". also when you say bad ipc is that the dash cluster or another module?

Logandiagnostic · #10 (**permalink**) 08-04-08, 09:43 PM

The ALDL is under a little cover above the parking brake. It is the connector where you would plug in a scanner.

The ALDL will have very small cavity letters molded in the plastic. Pretty sure it's pin M you need to measure. (I'll look in the manual when I get home)

While the car is running, the voltage will always be jumping around. When the problem is present, the voltage will be locked.

All the computers communicate on circuit 800. One of them is dragging the signal down, hence your problem.

The IPC is more often the problem. But could be one of the others: sdm, abs, acp, rss, ipc, ecm computers.

You can unplug each computer one at a time. Start the car, if the voltage is now ok, you found the bad one. This will of course set a bunch of codes for that system. But this is how its done.

The IPC is the dash cluster.

Logan Diagnostic LLC
www.ledfix.com
www.airbagcrash.com
www.logandieselusa.com

rayj · #11 (**permalink**) 08-04-08, 09:46 PM

are all the other modules the ones located on the back of the rear seat?

Logandiagnostic · #12 (**permalink**) 08-04-08, 10:19 PM

I think the RCC and ABS are behind the seat. Silver box in center is ABS.

The air bag DERM is above the brake pedal.

The IPC is the cluster.

ECM is behind the glove box. The ACP is mounted on the firewall inside behind and below the glove box.

Logan Diagnostic LLC
www.ledfix.com
www.airbagcrash.com
www.logandieselusa.com

rayj · #13 (**permalink**) 08-04-08, 10:39 PM

so after checking voltage on the pin you stated and all grounds were should i start with disconectiong the modules

Logandiagnostic · #14 (**permalink**) 08-05-08, 01:15 AM

I wouldnt worry about vehicle grounds right now.

I just got home and have the factory service manual in hand.

I was correct. Measure voltage between pin M on the ALDL and body ground. ALDL =(Assembly Line Diagnostic Link).

Technically, you can measure circuit 800 on either ALDL pins M or L.

The measured voltage should be rapidly fluctuating between 3-5 volts DC while the car is running.

If the voltage is locked. Turn off car, go unplug one of the mentioned computers. Retest. If problem now gone, you found the bad computer.

ABS and Traction ones are the easiest being they are in the trunk.

The top of the dash has to come off to get to the IPC.

Car will not run with a disconnected ECM.

Of course, a thousand codes will be stored while doing this procedure.

I suspect a bad IPC. I also suspect you need a 1992 IPC to replace a 1992 IPC. In 1993 the IPC changed a bit internally. So you can use a 1994 IPC in a 1993 and vise versus. But the 1992 IPC is a 1 year, 4.9L engine, unique IPC. I think..

Logan Diagnostic LLC
www.ledfix.com
www.airbagcrash.com
www.logandieselusa.com

rayj · #15 (**permalink**) 08-08-08, 11:26 AM

ok i tryeddisconecting the pcs as stated above but it did not change anything. the voltage is locked at 5 volts as you atated it would be above. i have a known good ipc from a 92 eldorado to install and try but i need to know how to remove the dash pad and trim to get it out. i found the 3 screws under the defrost vent but cannot figure out how to get the front apart, the 2 woodgrain pcs at the front i can loosen the bottom up but not the top. any help would be great.
Ray