can I drive until repair is done

[joanez]

I have a 1994 SLS with 130miles on it. My "Services your engine soon" light came on, also Traction disable,ABS,and Service ride control. My mechanic states My codes are P056,I need to replace the Tran mission input speed sensor. He cleared all codes out said to drive and see what happens. Well Services Your engine soon comes back..Code P056 comes back... This job includes a long list of checking wires etc at less 10 hours because he had to remove trans to get to replace the part This will be $900......ABS.....need a sensor replaced and T061..Motor pump Fault this on is History. Service ride control is I need Front struts one is starting to leak.(I have new about this it was my next thing to do) My main question is until I can get the P056 fixed will I do more Damage to Tran mission it I drive my car for at less two weeks. Thanks

[Cadillac Jim]

I'm not really comfortable on giving advice on the basis of what someone else tells you. The first thing to do is to read the codes yourself and post them here. In addition to the warning lights, please tell us any driving complaints you may have -- hard shifting, stiff ride, whatever. We can go from there pretty quickly.

I suggest that you drive the car for a block or two to warm it up, then, when you park the car, run the codes before you turn off the key (see the link in my signature block for how to run the OBD codes).

[Warspite]

My P056 code kept the transmission in 1st gear. Good thing! Most of it was toast after the water pump failed. I haven't even driven this car ('95 Seville SLS) yet, so who knows what else will pop up, like the PCM not properly communicating with other modules. My shop even replaced it, with a flash of the EPROM, and they're still not done chasing this down.

Other then the dreaded Northstar Head Gasket, it seems this P056 is the second-most "worst" code your DIC can report.

Good Luck!

[Cadillac Jim]

Warspite -- I think you really need to get aholt of that car and run the codes yourself and start your own thread. It sounds like someone has started throwing your money at it, and if they have already changed the PCM and flashed a new one, it may be too late to take control of its rehabilitation, but unless this is a restoration by a trusted friend, you should try. PCMs very rarely go bad, and then it's usually something like someone shorting a terminal while working on the car or hooking up jumper cables backwards or some such.

I once had my car pressure-washed under the hood and underneath after a detailing and it came out of the car-wash with all kinds of warning lights and codes and a miss. I let it dry out, cleared the codes, and none of them came back. There was no problem with the car.

A lot of things can cause a P056 and only one of them is a bad sensor. The sudden flashing of lights on joanez's car sounds more like an electrical problem than a mechanical problem to me, and that's why I want all of the codes on the car, as read by the owner, as well as hear about drivability issues. It's easy to check for the inexpensive fixes first and very often those solve the problem(s).

[MAC]

There is a specific test to determine if this code is being caused by a defective PCM as follows:

NOTES ON FAULT TREE: (From GM's 1994 Service Manual)

1. With engine idling at PARK or NEUTRAL PD72 should read between 50 and 100 RPM less than engine RPM.

2. The transaxle input speed sensor will generate a frequency of grater than 0 Hz when the vehicle is idling. If it does not check CKT [circuit] 1230, CKT 1231 and speed sensor for open/shorts inside the transaxle.

3. Checking CKT 1230 and CKT 1231 for opens or shorts to the PCM. If wire OK, the PCM is faulty.

To check Transaxle Input Speed, enter Diagnostics and select DATA and PD72. Notice # 1 above states that PD72 should read between 50 and 100 RPM less than engine RPM. If greater than 100 RPM then the fault is not present and is thus likely an intermittent fault, which may be caused by Electromagnetic Interference (EMI), such as sensor wires running along side spark plug wires.

[MAC]

My P056 code kept the transmission in 1st gear. Good thing! Most of it was toast after the water pump failed. I haven't even driven this car ('95 Seville SLS) yet, so who knows what else will pop up, like the PCM not properly communicating with other modules. My shop even replaced it, with a flash of the EPROM, and they're still not done chasing this down.

Other then the dreaded Northstar Head Gasket, it seems this P056 is the second-most "worst" code your DIC can report.

Good Luck!

Why would you think the transaxle is toast?

Also you can override transaxle shifts while the car is running, in DRIVE and traveling at speeds less than 65 MPH through PCM OVERRIDE feature and selecting PS11 override function and also selecting the WARMER and COOLER buttons accordingly to shift transaxle. This feature will override Shift Solenoids "A" and "B".

[rockfangd]

I dont know if this helps but when I had my 95 eldorado it supposably had a bad input speed sensor and it caused a service engine light, abs light, and traction control light. And many times it came up with a message stating speed was limited to 65 mph. after all of the attempts to try to solve the problem it seems it was the ISS. I never fixed it and it actually drove great. *(not saying I recommend it)

[Warspite]

Thanks, Gents! I'll get the car back this weekend - from what the shop told be, the solenoids (A& failed due to what they call, an obvoius overtemp condition (metal blued) and the water pump was shot. PCM diag was done at a Caddy dealer, who flashed the EPROM in the PCM, but is now "throwing his hands up" at it. Could it be that they just don't want to put the time into a '95? But the way I see it, 111K is only the half life of a flagship vehicle, and I've just sold a Q45 with 232K miles, and it was still a clean, sharp, and FUNCTIONAL ride. I expect no less from this SLS, once the bugs are ironed out.

[Cadillac Jim]

What it sounds like is that yoru local dealership no longer has a tech that is expert in the 1993-1999 Northstar cars and OBD I, and is willing to limit his income by spending that much time on one car.

Sometimes it's better to find an independent mechanic to work on an older car instead of taking it to the dealer. After so many years out-of-warranty, the techs just lose the recipe. Also, if 90% of the cars that come in are shiny new cars with superficial warranty repairs, no one wants to be the one to work on a dirty old car with multiple inscrutable problems.

I went through the transition about 2002 (90,000 miles, a bit late, actually) on my car. If I do this again, I'll start looking for an independent mechanic about the time my car goes out of driveline warranty, which was 50,000 miles on my car.

We haven't heard from joanez. We really don't want to hijack joanez's thread. Where are youuuuu joanez???

[joanez]

The tech told me that he cleaned all codes. I ran it any way here are the codes:

P056 H

I022 H

I032 H

I039 H

A037 H

T061 H

S023 H

No sir codes

I also went to PCM? code PD72 the number ran from 618 etc....up to 640????

The RPM on dash were about 700

Service Ride Control ....On

Traction Disabled....On

Anti-Lock (ABS).....On

Thanks

After all this went to store, she seems not to be ruining right. When I give her gas the RPM go up to 2200 at 35-40mph I am still at 1800 RPM. Sometime she shifts right (down to 1500) I THINK MY Nightmare is BEGANING......

[MAC]

The tech told me that he cleaned all codes. I ran it any way here are the codes:

P056 H

I022 H

I032 H

I039 H

A037 H

T061 H

S023 H

No sir codes

I also went to PCM? code PD72 the number ran from 618 etc....up to 640????

The RPM on dash were about 700

Service Ride Control ....On

Traction Disabled....On

Anti-Lock (ABS).....On

Thanks

After all this went to store, she seems not to be ruining right. When I give her gas the RPM go up to 2200 at 35-40mph I am still at 1800 RPM. Sometime she shifts right (down to 1500) I THINK MY Nightmare is BEGANING......

Looks like the PCM is fine or perhaps there is an intermittent fault, as the difference between PD72 reading and RPM is between 50-100 RPM.

I022 = Panel Dimming Switch Pot Circuit

I032 = Loss of ABS/TCS Data

I039 = Loss of Road Sensing Suspension Data

A037 = Loss of Instrument Panel Cluster Data

T061 = Motor Pump Circuit Fault

S023 = (I cannot locate this code)

You are getting "Multiple Data Communications Codes" (pg. 8C1-18 of 1994 GM Service Manual). My first guess is that the Instrument Panel Cluster (IPC) is defective since codes I032, I037, and I039 set. For example. I032 will set "if ignition is on and the IPC is not able to exchange data with the EBTCM." (Electronic Brake Traction Control Module) One sure sign it's defective is if you lose control of the IPC climate control and the fan turns on and will not shut off. This can happen intermittently and eventually it can become more frequent. There is apparently multiple data loss and loss of communications with the IPC. I suspect that T061 is setting because there is loss of data according to I032. The Pump Motor (See T061) returns brake fluid back to the master cylinder during anti-lock braking. With a loss of ABS/TCS data, I suspect it's setting the T061 code. Why exactly, is another question. However, I suspect it MAY be caused by a defective IPC. If this is the case, you can send it out to be repaired.

EDITED:

By the way, check the trunk fuse block for any blown fuses. If I remember, pay close attention to fuse A1. Also, check battery ground and make sure battery is free of corrosion and connections are good. The ground is located near the battery and is bolted to the front near the radiator.

[Cadillac Jim]

joanez -- these things are usually caused by one or two things, often simple electrical problems. If you checked the codes after driving the car but before turning the key off, the fact that all of your codes are H, e.g. History, means that none of them occur all the time. If you just turned on the key and checked the codes, they will pretty much always be History codes.

[MAC]

joanez -- these things are usually caused by one or two things, often simple electrical problems. If you checked the codes after driving the car but before turning the key off, the fact that all of your codes are H, e.g. History, means that none of them occur all the time. If you just turned on the key and checked the codes, they will pretty much always be History codes.

Actually, if there is a defective IPC (caused by a short circuit or loss of power) the codes will set as 'HISTORY', however, they will actually be 'CURRENT' since there is a loss of communication that would otherwise permit them to set as 'CURRENT'. Below is a quote from '94 Service Manual (pg. 8C1-18):

1. If I033, I034 and I037 are set, the IPC has lost communication with the entire data line. Codes P047 (PCM Loss of IPC Data) & I037 (ACP Loss of IPC Data) should also set, but since the IPC can't communicate with these devices, these codes can only be displayed as History.

[firefoot0315]

I have had I022 History sitting for awhile. Dimming potentiometer problem. It used to show as current when my dash lights were flickering, but lately when they flicker (a couple times a month for one night) it still reads History. Is that a lack of communication from the dimming pot? Other than that my only codes are a couple suspension circuit history codes. For as old as my car is and for as long as it sat idle, I count myself very lucky for having so few and such relatively minor issues.

[MAC]

I have had I022 History sitting for awhile. Dimming potentiometer problem. It used to show as current when my dash lights were flickering, but lately when they flicker (a couple times a month for one night) it still reads History. Is that a lack of communication from the dimming pot? Other than that my only codes are a couple suspension circuit history codes. For as old as my car is and for as long as it sat idle, I count myself very lucky for having so few and such relatively minor issues.

To begin, I022 deals with the headlamp/Instrument Panel Dimmer Switch. Unfortunately, it is possible that the Instrument Panel Cluster needs to be replaced. However, it's also possible that it's simply a matter of an open circuit somewhere or the dimmer switch needs to be replaced.

Enter Diagnostics mode and let it cycle through. Once Diagnostics reaches the end you can manually cycle through various systems by pressing the 'HI' and 'LO' buttons on the Climate Control Center (CCC) including PCM OVERRIDE, etc. Select 'INPUTS' and cycle through to ID42. Turn headlights 'ON' and turn dimmer switch through full travel each way and monitor for sudden jumps in the ID42 reading. If there is a problem, the reading will "jump from its normal value to a reading below 4%". You can also monitor the ID42 value while manipulating related IPC/Dimmer Switch wiring and monitor the reading for sudden jumps.

If the Dimmer Switch needs to be replaced, according to Fault Tree (on pg. 8C1-17 of GM Service Manual) the scenario would be that you would be "backprobe headlamp switch connector cavity 'B' to 'A' with a DVM and there is a reading of 8 volts or more despite having good contact at headlamp switch. If the contact is good, replace switch. If you continue to run into this problem, you may want to manipulate wires to see if it effects the flickering problem thereby indicating a loose wire or contact problem. Alternatively, replace the headlamps/Dimmer Switch and perhaps this will solve the problem.

[BodybyFisher]

I drove my 96 Deville over a year with a bad ISS speed sensor

[joanez]

Going out to check out ...."By the way, check the trunk fuse block for any blown fuses. If I remember, pay close attention to fuse A1. Also, check battery ground and make sure battery is free of corrosion and connections are good. The ground is located near the battery and is bolted to the front near the radiator"

also my driver side window is not working stuck in up. Motor needs to be replaced. Could this be my electric problem or just a added "Thing to do List" Thanks everyone get back to you soon.