It Never Fails, Except When It Does

[ol' yeller]

I have decided to sell my Reatta. A week or so after I make the decision, the car dies. After attempting to run diagnostics I felt I was in over my head. Sometimes the car starts and runs perfectly except that the CEL came on. Often it stalls and won't restart. Cranks but no restart. The IPC goes kerflooey and the door/key chimes sounds intermittently. If I am fortunate enough to get the car to restart, it runs like it has no power and eventually stalls out again.

I had the car towed to a local shop. They pulled the codes but there were about 7-10 of them. It was their opinion that there was probably just one fault that was causing the other codes. I don't have the codes right now but some were a voltage fault, and I think there were 2 ECM codes. They are doing some further diagnostics to try to narrow down the possibilities. At this point, they think the fault is in the IPC, an intermittant short or open or ground that causes the engine to stall and not restart. I will have the codes tomorrow. They are willing to further isolate the problem as long as my money holds out but I really don't want to make their February rent payment for them. Has anyone heard of a defective IPC causing the engine to stall? In the years I have been on this forum I have seen the IPC go blank but I can't remember seeing where one causes the engine to stall.

My feeling is that there is a bad ground somewhere, suggestions would be appreciated. Tomorrow they wash their hands of the problem or fix it. The shop owner felt I'd be better off replacing the IPC with a known good used one rather than running the fault to resolution. Thoughts? By the way, the car is a '90 and it has about 152K on the ODO. Never had an IPC problem or any other problem in the year and a half I have owned this car

Thanks

Greg

[Guest NEMO]

Replace the Crankshaft sensor that is the problem. The IPC should not effect the car running.

[padgett]

Power/ground issues could cause all. Need to start by probing various places with a DVM. What is the system voltage reading in the diagnostics (ED10) running and off ? Is the ALDL cover by the parking brake that says "Do not remove" in place ?

BTW the IPC gets its signals from the ECM/BCM, not the other way around. Going out on a limb a bit but I do not believe a bad IPC will make the car run bad.

Edited January 15, 2010 by padgett (see edit history)

[D-a-n-i-e-l]

IPC will not affect the engine running. I have pulled mine out completely and never had an engine problem. Also find a new mechanic. You have a simple sounding problem and they are trying to take you for a ride.

As stated above it is most likely the CPS, I would also put a 50% bet on the ignition control module.

[Guest mhuffy]

What were the codes? I am not convinced the CPS would be the problem. Granted, it would cause the car not to run, but don't see that it would cause the door chime and light issues.

Padget, you asked "Is the ALDL cover by the parking brake that says "Do not remove" in place ?" Is this just the little plastic cover for the computer access you are talking about? Having some challenges here, one is not always understanding terms that are being used.

Edited January 15, 2010 by mhuffy (see edit history)

[padgett]

Yes.

Edited January 15, 2010 by padgett (see edit history)

[harry yarnell]

I'm with NEMO on this one. Crank sensor.

[DAVES89]

I had a lot of irritating issues with my black gray, most of which turned out to be the ground wires behind the battery. Make sure they are good. Then like the others try the CPS and the ICM. Both are easy and relativly cheap fixes.

[Ronnie]

Location of the Negative Junction Box Location can be found on my website.

[Vincent Vega]

I'm going with the ground problem. Start at the battery and clean up every connector you find. You may even have a bad battery cable. IPC issue is a separate issue from your running condition. Getting the codes is a the best way to diagnose the problem. Post them here. A bad ignition module will not throw a code, but can cause a multitude of problems.

[Reattaron]

In the 90 FSM 0n page 8a-14-17......ground distribution, clean up the first 6 grounds. That will refer you to ...8a-201-7-d, the grounds that are on the radiator support & behing the battery near the fender. Also look at 8a-201-0-d, 201-8-c,& 201-9-a. Clean up the connections & put something on them to inhibit corrosion.

Reattaron

[padgett]

But the ICM doth not have chimes onnit. Need to clear up the power issue first. Others may go away.

[Ronnie]

Be sure to check your battery connections closely, I had lots of strange problems caused by a bad battery cable terminal. Battery Cable Repair.

[ol' yeller]

Thanks everybody for the suggestions so far. I didn't take the codes from the mechanic as he was going to do some further testing today. I'll pick them up tonight and post them later this evening. I wasn't buying the IPC being the cause either. He wasn't saying it was, he just suspected it.

You guys have a lot more experience with these cars than I do, but given that the car occasionally will start and run fine for a short while, wouldn't a crank sensor always be bad once it goes? When it runs, it runs great (with the CEL lit). It seems when it fails it is something telling the ECM or a sensor related to the problem not to supply fuel. I also suspect the bad ground is what is causing the IPC issues. The first thing the shop tested was fuel pressure and it was very good. I am leaning towards a bad ground ( I cleaned the ones on the core support in front of the battery but it appears there are more as Ronnie's website shows. If the shop doesn't find anything today, Ill bring the car back home and start chasing grounds, changing the crank sensor and/or the coil packs. Another thought is, could it be a plugged catalytic converter? I think that could cause the bad running issue but not the IPC issues. I've never had a car with this many miles so that is a new experience for me. Also are battery cables available? They look pretty complicated. Thanks and I'll post further tonight.

Edited January 15, 2010 by ol' yeller (see edit history)

[Guest Telco]

If battery cables need to be replaced and you aren't picky about it being 100 percent stock, I've had great luck using welding cable in place of actual battery cable. It's designed to live in a harsh, chemical filled, high heat environment. Plus, being made of many small strands instead of big, thick strands, they are far more flexible than battery cable.

The insulation is a little thin on it, but it's also tough to cut. For my own peace of mind, when I install welding cable I also wire loom it to get a little something between it and anything that might cause damage. It also only comes in black, so you need to mark any positive lines. I normally wrap the ends with red electrical tape and put a loop of red every foot or so on the positive leads.

I've run vehicles for years with welding cable instead of battery cable with no problems. The only thing that might be a difficulty is, the vehicles I've run them on are ones that aren't that sensitive to EMI. I have no idea if welding cable will cause any problems for a Reatta with the CRT stuff or not. The last vehicle I ran it in was my 1996 Tahoe, and I will most likely be redoing the primary battery circuits in my 2000 Silverado when it warms up. My own Reatta needs some battery attention as well, so it will also be seeing the welding cable treatment this summer. I'll be glad to post my results if anyone wants to try it but doesn't want to go first due to the potential CRT interference. I doubt there will be a problem, but until I've done something myself I don't like to say that there's definitely no problems.

[hinspect]

As far as the battery cables, instead of replacing mine on my old Blazer, I purchased new side terminal bolts to go in the cables from a local Advance Auto. It solved the problem on that one. They look like stock and no need to clean!

[ol' yeller]

Ok here are the codes. #43 ESC Module or Sensor Circuit, #51 ECM Prom Error, #113 in Car Temperature Circuit, 112 Air Conditioning Low Temperature, #333 Loss of Inflatable Restraint Data, 412 Battery Voltage too High, #420 Relay Circuit. ???

Greg

Edited January 16, 2010 by ol' yeller (see edit history)

[Guest mhuffy]

51 is the curious one to me. If you would have had a 42 also, I would say definitely ECM. I don't know what will cause a prom error, but being the fact it is a "plug and play" design, I wonder - did your mechanic mess with your ecm or could it not have a secure connection?

Also, have you ever cleared the codes? Some of these could be old and not related to what is going on now. Remove the battery cable to clear the codes wait a minute and put it back on. Then drive your car and see what codes you get. This may give you a different picture of where you are - at least it would be morer accurate, it doesn't cost anything, and it is easy to do.

[ol' yeller]

I removed the battery cables and cleaned them prior to taking them to the Mech. which would have cleared old codes. These are all new in the last few days.

[padgett]

All of these could be caused by erratic power. You are getting codes from ECM, BCM, and SIR. A bad ground to the battery can result in voltage spikes (voltage too high) from the alternator. Did it run at all after you reconnected the battery ?

[Guest mhuffy]

I have never professed to be a mechanic, just a fairly good parts changer that has experienced challenges along the way. That being said, I am always ready to receive instruction. My questions is: It is my understanding that the prom basically contains the car's hard data, i.e., tells the computer that this a Reatta and not a LeSabre. How would a power fluctuation cause a prom code?

[padgett]

From the factory, the PROM contains a checksum. If the voltage fluctuation made the ECM read either the checksum or a memory loacation rong, it would set the code.

PROM contains the program (top half of memory) and sytem maps and fixed data (bottom half). Changing ECM data including error codes is stored in a 1k RAM section in the 6809 (later 68HC11) CPU.

BCM uses the same system with the addition of a 2K 2816 EEPROM for nonvolatile memory storage (why the ODO is not lost when changing the battery).

[ol' yeller]

Padgett,

When I disconnected/reconnected the battery, the car fired right up. It was then that I cleaned the battery cables, the terminals and the 2 ground connections in front of the battery. The cables appear to be in good shape with little to no corrosion and only slight rust on the center attaching bolt. It was running so well, I decided to take it for a spin. After 2 blocks, the car died and was hard to restart and the CEL relit. It finally restarted and I was able to limp home with barely enough power to make it up the hill to my house.

This is why I suspect a ground issue rather than an equipment issue. I will be retrieving the car on Monday and hope to have time then to check out what is suggested here. The shop still suspected the IPC but after talking to me, backpedalled a bit. One way to eliminate the IPC as a cause would be to remove it completely and see if the problem goes away. That would be down on my list of things to check. Their final report says, "Dash and interior lights intermittantly go off with the vehicle stationary. Suspect poor ground or power connection within harness. Possible malfunction within dash display unit. Possible malfunctioning electronic control unit or PROM unit. Inspected for obvious open circuits, none found at this time. Needs further diagnosis to determine."

I guess I'm going to have to educate myself on the electronic happenings in my Reatta. I do have a service manual and the trouble shooting section appears to be fairly straight forward. Prior to reading the manual, I bought an OBD1 & 2 scanner but when hooked up to the port I got a message that the vehicle wasn't communicating with it. I have since returned the scanner as it appears the on board diagnostics tell me the same thing. Ironically, I am looking forward to figuring this out on my own with everyone's help. If it doesn't frustrate me too much, I may just keep the car as I will understand it better. As of right now it, has the potential to be a piece of yard art at the end of my driveway. I can't sell it in the current condition and it is too nice to part out or send to the junkyard. I really do appreciate the willingness of you all to help a somewhat novice. I am a fair wrench but a lousy diagnogstician. I completely understand my '65 Skylarks. Newer cars baffle me but I'm an old dog willing to learn new Buicks. Very sincere thanks again!

Greg

[Ronnie]

Have you cleaned the connections on the ground terminal block behind the battery?

[ol' yeller]

Power/ground issues could cause all. Need to start by probing various places with a DVM. What is the system voltage reading in the diagnostics (ED10) running and off ? Is the ALDL cover by the parking brake that says "Do not remove" in place ?

BTW the IPC gets its signals from the ECM/BCM, not the other way around. Going out on a limb a bit but I do not believe a bad IPC will make the car run bad.

I have a relatively inexpensive DVM from Sears. My concern is that I have read that some DVMs can cause more trouble than they isolate. I'd hate to fry an expensive component using an inferior DVM. How can I tell if mine is OK to use?

The ALDL cover was on until I plugged in the OBD scanner mentioned in my prior posting. It was unplugged during my short and fateful test drive. I have no knowledge if the mechanics reinstalled it.

I can check your question about the system voltage reading after I retrieve the car on Monday.

Greg

[harry yarnell]

Again, this is consistant with a bad crank sensor.

[ol' yeller]

Have you cleaned the connections on the ground terminal block behind the battery?

Yes

[ol' yeller]

Again, this is consistant with a bad crank sensor.

Thank you Harry, On Monday my plan is to check the grounds enumerated in a previous post. Thanks to that poster for giving the pages in the manual where they are located. If that doesn't cure the problem, I will inspect and replace the crank sensor. It would help me to know what to look for to spot damage to the sensor. I think the crank sensor is relatively inexpensive. I know one of the quickest routes to financial ruin is to throw parts at a Reatta electrical problem so I am trying to do a better job of diagnosing than I usually do. Coil packs would be next after the ground/connectivity check and crank sensor replacement. Right?

Greg

[Ronnie]

One easy thing you can do easily is to visually inspect the ignition control module. (The coils mount on top of it). Look for any pasty looking stuff oozing from it. That is a sure sign that it is defective. As has been said already, the crank sensor is a good candidate for causing the problem you are having

[Vincent Vega]

Ronnie pointed out the ooze in the ign module. The stuff acts as a heat sink. When the ign mod gets too hot it will fail. Starts and runs when cold? Dies, hard starts and poor running after it warms up? Sounds heat related. Like bad ign module.

[ol' yeller]

Ronnie pointed out the ooze in the ign module. The stuff acts as a heat sink. When the ign mod gets too hot it will fail. Starts and runs when cold? Dies, hard starts and poor running after it warms up? Sounds heat related. Like bad ign module.

Not heat related. It dies upon cold start. Sometimes it runs great after cold start, sometimes it won't start or run, hot or cold. It's good to know what a defective coil pack looks like. My question was more about how to tell a defective crank sensor.

Greg

[Ronnie]

If the problem is a defective crank position sensor you will not have spark to the plugs during the time it is acting up. Sometimes the sensor does not fail all at once and will act up with the not starting or keep running symptoms you describe and then start to run again for a while. However I don't believe it will cause chimes to sound, lights to flicker or other symptoms that you said you are having. I don't believe it will cause the ECM to set a code but maybe it could under certain conditions.

One way to help narrow the not starting or running problem down to the crank position sensor it to pull a plug wire and check for lack of spark immediately after it fails to run. Actually the best thing to do is change it out with a new one to eliminate it as being a problem.

[harry yarnell]

Be advised, that since your mechanical skills are still in the 50's (not an insult), that the crank sensor isn't easy to replace. The harmonic balancer must be removed, and the alignment of the sensor is critical.

[Guest Telco]

Ok here are the codes. #43 ESC Module or Sensor Circuit' date=' #51 ECM Prom Error, #113 in Car Temperature Circuit, 112 Air Conditioning Low Temperature, #333 Loss of Inflatable Restraint Data, [b']412 Battery Voltage too High, #420 Relay Circuit. ???

When I disconnected/reconnected the battery' date=' the car fired right up.[/b']

These two posts point DIRECTLY at an electrical power problem. First you have new, disparate codes set on electical items, second you were able to change the state of the problem by fiddling with the battery connections. Before anything else is checked, I'd get the electrical issue resolved.

GM has had a problem with the plastic covered positive battery cable, there is a lead washer inside and when the battery cable is removed and reattached, this washer gets flat and distorts. This can cause intermittent connections that will act like what you have. This is really a problem on full size trucks, but if the Reatta has the same red plastic covered positive terminal it could be an issue here as well. The fix is to cut the plastic off the terminal, and either replace the lead washer with a steel/brass/copper/stainless steel washer, or get a shorter battery bolt that doesn't require the washer.

This problem can also cause the bolt to tighten too far into the battery, which cracks the positive terminal inside the battery. This will cause acid in the battery to leak out where it will be wicked down the positive cable. If not found before it reaches the other side of the cable, it will damage the component it's bolted to. More than one starter has been replaced due to this problem.

I think before I'd throw any components at this problem I'd make 100 percent sure that there are no power issues. This would mean replacing the battery cables, and making sure that none of the cabling connectors used have those stupid molded-on covers on them. I would suggest replacing the primary electrical lines as a whole, ie battery to body/frame ground, battery to block ground, block to body/frame ground, battery to alternator, battery to starter, and battery to electrical distribution center (if the Reatta has one, that is, haven't had mine long enough to know what all it has).

[Guest mhuffy]

There are a couple ways to replace the CPS without removal. A good instructional link is posted in the forum. I didn't have the courage to do it at the time and printed it off, gave to my mechanic. Worked like a charm. If you are going to try the CPS, I would encourage you to try it rather than pulling the harmonic balancer.

I will also add that when my sensors failed (yes it went out on both cars), there was no loss of power or limping. It was just dead. I checked the fuel pressure and it was fine. I checked the plugs for the fuel injectors and there was no electrical pulse, I checked the ignition and there was no fire. The cars were just dead and never tried to restart again.

I did have an issue with my 90. Unless you let the car warm up to operating temperature, it would die, be hard to start, and barely move, my check engine light would be on. I would have to turn it off - restart it - and let it warm up - then it drove all day long. That ended up being my ECM. I changed it out (73.00 exchange at Advance) and it has been fine for the last 4K miles. I did change coil packs, ICMs, and a few other sensors trying to rectify the problem. In short I played with about 450.00 mistake to come to the conclusion it was a 73.00 problem.

Changing components can get expensive. My recommendation wo with the lowest cost and easiest.

Marc

Edited January 16, 2010 by mhuffy (see edit history)

[Ronnie]

There are a couple ways to replace the CPS without removal. A good instructional link is posted in the forum.

Marc

Could you please direct me to the link for instructions on changing the sensor? I would like to add that to my website so it will be easy to find. I searched the this forum and could not find it.

Thanks!

[Guest ReattaRobert]

GM has had a problem with the plastic covered positive battery cable, there is a lead washer inside and when the battery cable is removed and reattached, this washer gets flat and distorts. This can cause intermittent connections that will act like what you have. This is really a problem on full size trucks, but if the Reatta has the same red plastic covered positive terminal it could be an issue here as well. The fix is to cut the plastic off the terminal, and either replace the lead washer with a steel/brass/copper/stainless steel washer, or get a shorter battery bolt that doesn't require the washer.

This problem can also cause the bolt to tighten too far into the battery, which cracks the positive terminal inside the battery. This will cause acid in the battery to leak out where it will be wicked down the positive cable. If not found before it reaches the other side of the cable, it will damage the component it's bolted to. More than one starter has been replaced due to this problem.

The lead 'washer' (which is actually about 3/8" thick) is only used if the vehicle has two positive cables on it such as diesels with two batteries or police vehicles with an isolated positive power post, etc. It is 'sandwiched' between the two positive cables at their battery ends.

My Reatta (and I suspect all Reattas) uses a single positive cable so the lead 'washer' is not an issue.

Also because of the single postive cable on our cars, the second point above, i.e., the tightening of the cable bolt and cracking the battery, etc, is also a not an issue as the single cable's bolt contact surface is basically not compressable unless you use an 18" breaker bar on the 5/16's bolt head!:cool:

[Guest NEMO]

First you cut off all the plastic/rubber off the +and - cable ends. Then you cut off the plastic on the battery. YES you will see there is a lip of plastic on the battery where the side posts are bolted to hold the cables on. This lip is to seal the cable to the battery. I have been cutting these plastic parts off for years on all my cars. It lets you see what is going on with the connections.

[ol' yeller]

Be advised, that since your mechanical skills are still in the 50's (not an insult), that the crank sensor isn't easy to replace. The harmonic balancer must be removed, and the alignment of the sensor is critical.

Actually Harry, my mechanical skills are still in the 60's not the 50's....LOL. No insult taken. Prior to retirement I was a National Account Manager for a Telcom. I designed and sold wide area networks to large business customers. I understand some of the technology that is used to keep these cars running but not in an automotive context. Also, since I retired 6 years ago, that is when my knowledge ceased to advance with technological changes.

I am still leaning towards an electrical problem as the primary offender. I read the service manual and it mentions the use of a specific tool to align the sensor. Is it necessary and where would I find one? Any ideas on cost?

[Ronnie]

The lead 'washer' (which is actually about 3/8" thick) is only used if the vehicle has two positive cables on it such as diesels with two batteries or police vehicles with an isolated positive power post, etc. It is 'sandwiched' between the two positive cables at their battery ends.

My Reatta (and I suspect all Reattas) uses a single positive cable so the lead 'washer' is not an issue.

Also because of the single postive cable on our cars, the second point above, i.e., the tightening of the cable bolt and cracking the battery, etc, is also a not an issue as the single cable's bolt contact surface is basically not compressable unless you use an 18" breaker bar on the 5/16's bolt head

You are correct about the cable not having a lead washer but there is a problem with the bolt bottoming out in the battery and not securing the cable end tightly against the battery post. It happened on my Reatta this past Summer. I don't know if is caused by the metal compressing or wearing but the bolt on mine was be tight but the connection was be loose. It caused the IPC and the CRT for start flashing on and off erratically and the AC quit working. The ABS pump also was working sporadically. The car would still crank over but got where it would start and the immediately die. Then it finally got to the point that it would not crank over at all. That is when I was able to trace down the problem. I have a post here on the forum somewhere that documented the whole ordeal.

Read about it in this thread

To rectify the situation I removed the bolt by prying it out of the plastic cable covering (without cutting anything) and placed a copper washer under the head of the bolt and reinstalled the bolt. That allowed the bolt to tighten the cable end that looks like a washer to the battery correctly. Then all the problems I was having went away. I think others have experienced a similar situation.

It is possible that the cable is not actually the culprit. The problem could be caused by some batteries not having the post drilled and tapped to the proper depth which might cause the bolt to bottom out in the battery before the cable end is clamped sufficiently to make good contact. Grinding off the end of the bolt to keep it from bottoming in the battery post might remedy the problem. I wish I had investigated that before installing the washer.

One thing is for certain. The bolt holding the cable to the battery was tight but the cable end was still loose enough that it could be moved up and down easily by hand. Installing the washer under the head of the bolt corrected the problem.

As info for anyone reading this... if you have the bolt tight and you can still move the cable up and down easily you have the same problem that I did. Do not over tighten the bolt to tyy and get it tighter.

Edited January 16, 2010 by Ronnie (see edit history)