Until This - I Bragged About Chevy Reliability

[rowiebowie]

Started the van today to leave on a 21 day/5,000 trip. But before I got to the end of my street, engine stated running rough. Got "reduced power" message along with "Stabilitrak" and "ABS" warnings.

Limped back home at about 15mph top speed and let the van sit in the driveway for an hour while I furiously googled possible causes. I was unsuccessful.

I finally restarted the van and it seemed ok other than the check engine light. Drove it a few miles to Autozone for code readout. "P1682 - Ignition Circuit Malfunction" and "C0242-71 - Powertrain Control Module Indicated Traction Control - Invalid Data". The check engine indicator cleared after readout and went back home for more googling.

After another unsuccessful hour, which turned up zero results for "Ignition Circuit Malfunction", I'm thinking the problem was just a momentary glitch that had resolved itself. But far from it.

We decided to try and leave again but got only a few miles before the dreaded codes and reduced power returned so we turned around. A brief pause to turn off the engine and restart returned full power, but only momentarily. About half way home (still 3 miles away) the reduced power message resumed and just as I was turning into a convenience store parking lot to get off the street the engine died completely, never to start again.

I was actually lucky to have had enough momentum to coast into the parking lot of a 24 hour convenience store, who were cool with me leaving it there overnight (what choice did they or I have on Sunday afternoon). No dealer lots were open, so I'm staying in it and have a tow truck scheduled for 7:30am to get it to a Chevy dealer 2 miles away.

So my uber dependable, couldn't praise it enough, '2011 Chevy Express has now let me down. And unless a miracle fix gets us on the road tomorrow, we may have to say goodbye to the Badlands, Yellowstone, etc. until next year.

[GeorgeRa]

Sorry you have problems. Did you inspect wiring harness near ECM, perhaps unplugging and plugging ECM could help. Ignition and traction control are in different systems hence wiring.

[booster]

http://https://www.gm-trucks.com/for...tp1682-repair/

P1682 Chevrolet Description
The second ignition 1 voltage circuit is supplied by the run/crank relay through a fuse, and is used to power the remaining internal ECM circuits. If the ECM detects a voltage difference between the 2 ignition 1 voltage circuits, DTC P1682 will set.


Looks like a possible ignition switch, relay or fuse issue?


https://www.rockauto.com/en/moreinfo...t=4700&jsn=932

[rowiebowie]

Originally Posted by GeorgeRa

Sorry you have problems. Did you inspect wiring harness near ECM, perhaps unplugging and plugging ECM could help. Ignition and traction control are in different systems hence wiring.

Thanks. Upon your suggestion I disconnected the battery and then removed the two wiring harnesses from the ECM. Of course nothing looked suspicious but it's hard to see the actual pin connections. No soot or other sign of heat and there was no change after reconnecting. But I appreciate the advice and it was worth a try.

[rowiebowie]

Originally Posted by booster

http://https://www.gm-trucks.com/for...tp1682-repair/

P1682 Chevrolet Description
The second ignition 1 voltage circuit is supplied by the run/crank relay through a fuse, and is used to power the remaining internal ECM circuits. If the ECM detects a voltage difference between the 2 ignition 1 voltage circuits, DTC P1682 will set.


Looks like a possible ignition switch, relay or fuse issue?


https://www.rockauto.com/en/moreinfo...t=4700&jsn=932

Thanks. Worktruck2011's post seems like it describes my problem. If the van was in my driveway and I had the time, it seems like something I could tackle (the module, not the ignition switch part). But will wait so see what dealer says tomorrow, which is most likely what the gm forum describes but with several $$$ added to the price.

It also brings to mind one other symptom I did not mention and that only surfaced once the engine died for good. If I try to start by turning the key, there is mostly no reaction except for the dash board lights. But every other try or so, there is a brief period of no reaction, then even after releasing the key, the starter engages for a few seconds on its' own. Engine never fires, but it's a weird delayed reaction.

[rowiebowie]

Spending my first ever solo night in the van. So far the cantankerous generator is running the ac to keep me comfortable and temps are down from mid 90's to the super cool mid 80's as of 8pm.

Not my idea of great boon docking, but better than leaving the van unattended over night. Not an especially bad, but not especially good part of town. 24 hour convenience store is well lit and not too busy. But I'm just off the entrance to the CAT scales and clerk told me they usually get busy Monday mornings.

Oh well, I don't plan on sleeping that well anyway.

[booster]

Originally Posted by rowiebowie

Spending my first ever solo night in the van. So far the cantankerous generator is running the ac to keep me comfortable and temps are down from mid 90's to the super cool mid 80's as of 8pm.

Not my idea of great boon docking, but better than leaving the van unattended over night. Not an especially bad, but not especially good part of town. 24 hour convenience store is well lit and not too busy. But I'm just off the entrance to the CAT scales and clerk told me they usually get busy Monday mornings.

Oh well, I don't plan on sleeping that well anyway.

Time to pretend the traffic noise are waves and you are on Galveston Island

[TX-Trek]

You might want to check the wiring harness that often winds up sitting on the top of the driver side upper control arm. If I remember right it feeds from the ECU.

The movement of the arm eventually wears through the wire loom and into the wires. The result can be a variety of codes that sometimes are intermittent.
It's a more common issue than you might think on these vans.

The stabilitrak light can come on when the ECU commands a CEL on. This can often lead into chasing this as an issue, but this is simply a default shutting down that system until the real issue is corrected. Same as if you may see a bunch of module codes - more likely it's just one issue thats impacting the circuit they share.

Be careful about autozone or similar parking lot diagnosis. Yes they can look at a code but it's not always the component listed needing replacement. Until wiring/connections are verified you don't get the whole picture. That includes power, grounds, reference/signal voltage depending on the particular circuit.

Suggest also that any owner have a scantool, even a cheapie version can give codes and live data. I keep one in every vehicle and a more expensive bi-directional unit in the garage. Usually you're out somewhere when the CEL happens. You'll be able to at least get an idea immediately of what the CEL is about.

[rowiebowie]

Originally Posted by TX-Trek

You might want to check the wiring harness that often winds up sitting on the top of the driver side upper control arm. If I remember right it feeds from the ECU.

The movement of the arm eventually wears through the wire loom and into the wires. The result can be a variety of codes that sometimes are intermittent.
It's a more common issue than you might think on these vans.

The stabilitrak light can come on when the ECU commands a CEL on. This can often lead into chasing this as an issue, but this is simply a default shutting down that system until the real issue is corrected. Same as if you may see a bunch of module codes - more likely it's just one issue thats impacting the circuit they share.

You could be right. I'm at the Chevy dealership (one hour in at this point) and of course, no word yet. They seem very busy, but I'm only one of two people waiting. Wonder if that increases their urgency on my behalf? Probably not.

[avanti]

Originally Posted by rowiebowie

You could be right. I'm at the Chevy dealership (one hour in at this point) and of course, no word yet. They seem very busy, but I'm only one of two people waiting. Wonder if that increases their urgency on my behalf? Probably not.

See, now, if you owned a Sprinter, you would be sipping fancy coffee and munching on biscotti now. I have munched a LOT of biscotti.

[mkguitar]

Originally Posted by TX-Trek

Suggest also that any owner have a scantool, even a cheapie version can give codes and live data.

I have a obdII scanner and OBDFusion app on my phone to read codes, monitor function (live) and reset codes


thanks for your tip, I'll go look today.


a split piece of hose over a wiring harness can save from rubbing


split hose lengthwise, and secure with a couple of zip ties.


Mike

[booster]

[QUOTE=mkguitar;132313]

Originally Posted by TX-Trek

Suggest also that any owner have a scantool, even a cheapie version can give codes and live data. QUOTE]


I have a obdII scanner and OBDFusion app on my phone to read codes, monitor function (live) and reset codes


thanks for your tip, I'll go look today.


a split piece of hose over a wiring harness can save from rubbing


split hose lengthwise, and secure with a couple of zip ties.


Mike

Yeah, I think for the issue at hand you might need one of the brand specific diagnostic tools. In past days that probably ended around 2007 ( I haven't tried yet on our 2007) that would be a Tech2 scanner that will show all the inputs and outputs and give the option of manually triggering many of them. It would allow you to see the input to the ignition module if it is there adequately and also see the the output. These are functions that are way beyond the capability of most store bought scan tools or a Scangauge (which we do have on both the 1996 Roadmaster and 2007 Express van). I think the Tech2 will work for some later years but needs a GM subscription service to do it, which is quite expensive to get.

[TX-Trek]

I did that hose/zip tie cover in a number of spots as a preventive maintenance thing when we first bought our RT, very easy. Something that just came to mind is to also suggest cleaning every ground on the vehicle that you can find. A bad ground can certainly cause circuit or network issues. A good wiring diagram will show you the grounds.

I'm not an autel sales guy but I do own a couple. Before I bought my MaxiSys bi-directional scantool I used their MD808pro that allowed access (but not manual control) into the vehicle modules.i I keep that one in my car, and for our other vehicles a basic Launch CR319 works fine to keep in the glove box.

The MD808Pro (or another brand equivalent) will allow you to see inputs/outputs and status of the various modules even if you can't manually control them. That can go a long way to help diag direction as to whether its a control or component problem.

For our other vehicles I use a mfg-specific WIS/EPC factory service software but I've found Mitchell online DIY to be pretty good for the Express. 3 years access is about $45 and I've used it a lot, not just for service but to look something up. Includes full wiring diagrams.

To the OP I hope you find the issue and that its not a wallet-buster.

[rowiebowie]

First thing Monday morning (9/20) my van was towed 2 miles to the closest Autonation Chevy service center. I told them I would wait for service (hoping they'd put me in a priority que) since they seemed very busy. From the waiting room I hear a receptionist repeatedly telling people on the phone they were booked up until Thursday.

But they got to my van within a couple of hours and after extensive testing of 40 miles, the service tech had me come to the counter to speak with the mechanic. He stated I had a bad connection at relay 49 "Ignition/Trans" (if I recall correctly). He cleaned the connection, coated with some dielectric grease and considered the problem solved at about 12:30pm. $196 +tax with most of the labor for test driving, but I appreciated the thoroughness. But as you can read at the end, I later take away the thoroughness compliment.

We quickly put the food back in the fridge and hit the road a day late, making our state park about an hour after dark and 240 miles later.

Tuesday we planned on driving a double-leg of the trip (almost 500 miles) in order to get back on schedule. About 200 miles later the dreaded problem returned. At 65mph on a rural two-lane highway, there was the transmission clunk, dash lights, messages, and the engine died immediately. We coasted to a small pull-off on the side of the highway. If all this seems bad, and it was bad at the time, the story does have a happy ending.

Since I now knew where to look, I opened the fuse box under the hood and saw 5 identically part-numbered relays (with several open slots not used). I pulled #49 and swapped it with the A/C relay because it seemed the most expendable item.

Sure enough, the engine started fine and we had no A/C which told me it was a bad relay. Twenty miles up the road at the closest Autozone, the code readout was identical to the initial problem. I picked up two more relays. One got the A/C working and other is now a spare. Got an additional 250 miles under our belt that afternoon.

Today, Wednesday, we are back on our trip schedule and made an additional (and more reasonable) 235 trouble-free miles. Now pretty confident we have fixed the problem.

Lessons Learned:

1) A $30 replaceable part will leave you stranded.

2) The dash messages and OBDII codes (at least from inexpensive OBDII tools) will not lead you to a specific problem relay. But I guess the code mentioning ignition might make you look first at the relay with "IGN" in its' label name.

3) The mechanic did one very wrong thing by not throwing in a new relay while he was at it since the problem was either the connection, the relay, or a combination of both. So why not be safe and treat both potentials since he was aware we were heading out of town on a lengthy trip.

[rvsprinterguy]

Glad to hear you got it fixed! Hope your trip is trouble-free the rest of the way.

[booster]

Glad you got going, that was close to a disaster.


Take a good look at the baffle that is supposed to divert water from the hood gap away from the fuse box to make sure it is there and working OK.


Then take a look in the driver side wheelwell, where you may find open holes that allow wheel splash onto the fuse box (ours had those openings and I sealed them up very early on after we got it new).



Water in the fuse box corrosion is a known problem and probably due mainly to those two items. Whether or not that caused the relay failure is unknown, but certainly is possible.

[GeorgeRa]

Congratulation and keep safe. I always carry an OBD reading tool, ScanGauge and recently purchased Thinkcar which is for Mercedes. There are many of them to choose. https://www.amazon.com/thinkcar-Scan...ct_top?ie=UTF8

[TX-Trek]

Sounds like a good ending.

I frequently am in local wrecking yards and I've gotten relays and hi-amp fuses for literally pennies. I keep them stashed in the travel toolbox.

I'm also curious as to why the tech didn't replace the relay but at least you did. They do weaken over time. I hope he didn't jam dielectric grease down into the terminal slots - it's non-conductive and can hinder direct contact.

Do check that harness by the control arm though, a few minutes can save later grief.

Glad it's back up running.

[k1hog]

On the Road Again.

That is good.

[booster]

Originally Posted by TX-Trek

I hope he didn't jam dielectric grease down into the terminal slots - it's non-conductive and can hinder direct contact.

I don't think I understand what you are saying here as grease of ever evolving types has been a standard on connectors for decades. In general, from what the manufacturers have told me about the connectors they sold was that grease does a bunch of stuff. It lubricates the sliding connections to prevent a galling, it coats the conductive pins or blades to prevent oxidation, it fills the areas and helps any seals seal better to help prevent water and corrosives intrusion. The actual conducting area, which tends to be quite small and wiped when plugging in pushes all the grease out of the way so conduction is not affected. The only downside I have heard of grease in connectors was related to heat dissipation but my bet is that the connectors were either corroded already or overloaded a bit. You certainly wouldn't want conductive grease as that would cause leakage.


Do you have a source on the no grease in pin area problem. It is very new to me and I have always greased connectors for 50 years as soon as I get a used vehicle or have the connectors apart. I just had the entire drivetrain out of my 96 Buick Roadmaster and when it all went back in you can bet all the connectors got silicone grease in them. No issues on restart with any of them, just like I have seen in the past, even though this car must have had 20 connectors just for the drivetrain areas.