: So many issues... Don't know where to start



Othniel13
11-05-12, 11:44 AM
I have a few different problems with my 05 Escalade ESV. It has 138,000 miles but I bought it with 100k so I have no idea what has been done before I had it. I love this truck but I have been beating my head against a few issues that I cannot figure out. My thought is, perhaps they are all related, somewhat related or completely independent.

Problem 1 - I get a check engine light that comes on every so often but goes away within a day. I have stopped at Oriellys and Advanced auto and they cannot read the codes. In fact, they cannot even interface with the OBD port at all. So I have no idea what the code(s) might be. Anyone have this issue?

Problem 2 - Engine runs rough when warm at idle. I am assuming that this may be an O2 sensor but again, not sure which one because can't get the codes. I replaced wires and plugs about 10k ago and rechecked everything to be sure all was tight and no broken plugs/wires...

Problem 3 - the onboard nanny dings at me that I need to tighten the fuel cap. I replaced the fuel cap and it still does this about every 500 miles. I tighten and sometimes it tells me again, sometimes it doesn't and sometimes the CEL comes on.

Problem 4 - My truck will, at random, will not start. When I say random I mean that the truck can sit for 24 hours and start fine but then out of the blue it will not start after sitting for 10 minutes. I turn every single accessory off including all the perimeter lights, etc but the battery will still be drained. I have had a load check on the battery 3 times and it comes back great. The Starter tested good too. Alternator is showing that it is charging but it is charging at below 14 and jumps around on both the meter and on the gauge. It is rarely ever above 14.

I have recently replaced the stepper motors on the cluster, the oil pressure sending unit and checked all the wiring when I had the dash apart. Nothing obvious in there.

I love this truck but I am chasing a ghost at this point. I have thought that perhaps I should replace the alternator, and an O2 sensor but not sure what that will do. I also saw a post about the rear air, perhaps that could be draining the battery? Any help is appreciated.

the cadillac man
11-05-12, 01:06 PM
I have a few different problems with my 05 Escalade ESV. It has 138,000 miles but I bought it with 100k so I have no idea what has been done before I had it. I love this truck but I have been beating my head against a few issues that I cannot figure out. My thought is, perhaps they are all related, somewhat related or completely independent.

Problem 1 - I get a check engine light that comes on every so often but goes away within a day. I have stopped at Oriellys and Advanced auto and they cannot read the codes. In fact, they cannot even interface with the OBD port at all. So I have no idea what the code(s) might be. Anyone have this issue?

Problem 2 - Engine runs rough when warm at idle. I am assuming that this may be an O2 sensor but again, not sure which one because can't get the codes. I replaced wires and plugs about 10k ago and rechecked everything to be sure all was tight and no broken plugs/wires...

Problem 3 - the onboard nanny dings at me that I need to tighten the fuel cap. I replaced the fuel cap and it still does this about every 500 miles. I tighten and sometimes it tells me again, sometimes it doesn't and sometimes the CEL comes on.

Problem 4 - My truck will, at random, will not start. When I say random I mean that the truck can sit for 24 hours and start fine but then out of the blue it will not start after sitting for 10 minutes. I turn every single accessory off including all the perimeter lights, etc but the battery will still be drained. I have had a load check on the battery 3 times and it comes back great. The Starter tested good too. Alternator is showing that it is charging but it is charging at below 14 and jumps around on both the meter and on the gauge. It is rarely ever above 14.

I have recently replaced the stepper motors on the cluster, the oil pressure sending unit and checked all the wiring when I had the dash apart. Nothing obvious in there.

I love this truck but I am chasing a ghost at this point. I have thought that perhaps I should replace the alternator, and an O2 sensor but not sure what that will do. I also saw a post about the rear air, perhaps that could be draining the battery? Any help is appreciated.

Given how you said the truck is running and the inability to get codes I am suspecting the PCM is failing(FYI the PCM controls the alternator)as the battery drain means it has a internal short causing it to stay active even with the key off

Cause the PCM controls the engine and tranny along with the transfer case it also stores the mileage

The no start is it cranking and not turning over or nothing from the starter at all(if the second one then the PCM is failing for sure and the bcm is losing communication with the PCM causing it to lock out the starter

I know how it feels I had the PCM fail in mine(luckily I wasn't on the interstate)it showed reduced engine power then the shit hit the fan and everything went nuts and the truck wouldn't do nothing(lights radio everything in the cab worked(with the exception of the gear selection screen acting weird) four days later and about a week off the road it was fixed(it sat for 2days at my house while I checked my wiring for shorts.

Othniel13
11-05-12, 01:21 PM
The cadillac man, thanks for the reply. your first sentence about the reasoning for the PCM issue seems solid. Something is draining the battery for sure but like I said, I go through and turn off everything, unplug everything... my wife teases that I am like a pilot shutting down the plan.... HVAC - off, radio- off, lights - off.... lol

When it does not start, the starter will crank once or twice then click, depending on how dead the battery is. Its it just strange because it will start anywhere from strong to weak to dead. This no start thing has been going on since the summer but getting worse, meaning happening more frequently (once a month, then once a week, then once every other day). All it needs is a jump or a charger for about 10 mins. Then it will start. I drive a ton for work so I have prob put 30K on it since Jan. Do you have any suggestions for checking for shorts?

----------

Quick question about the PCM... do I need that programmed by the dealership if I find one online?

the cadillac man
11-05-12, 01:45 PM
The cadillac man, thanks for the reply. your first sentence about the reasoning for the PCM issue seems solid. Something is draining the battery for sure but like I said, I go through and turn off everything, unplug everything... my wife teases that I am like a pilot shutting down the plan.... HVAC - off, radio- off, lights - off.... lol

When it does not start, the starter will crank once or twice then click, depending on how dead the battery is. Its it just strange because it will start anywhere from strong to weak to dead. This no start thing has been going on since the summer but getting worse, meaning happening more frequently (once a month, then once a week, then once every other day). All it needs is a jump or a charger for about 10 mins. Then it will start. I drive a ton for work so I have prob put 30K on it since Jan. Do you have any suggestions for checking for shorts?

----------

Quick question about the PCM... do I need that programmed by the dealership if I find one online?

I suggest going to the dealer for the PCM but most parts place can order one if you have the vin and mileage(FYI the radio still gets power even with the key off as it is controls via the data bus in the truck)

Ps I had 122,000 give or take on my truck when I got it not it has over 150,000 miles as I drive back and forth to collage classes(and make long distance trips a few times a year) yet my truck looks as great as the day I got it.

jnrsesv
11-05-12, 04:23 PM
I find it very strange that the OBDII code readers won't connect. Any explanation why at your Advanced or O'Riellys Auto Parts stores?

I have read and reread your OP, even though the battery is showing a charging situation, you may have a bad cell. I personally would look at the battery first. There should be a label on it with the month and year that it was installed. Also have a look at the positive and negative battery connections. Don't just pop the hood and look, but rather use an 8mm box end wrench and remove each from the battery. You may be surprised with the dreaded blue corrosion, warm water and baking soda mixed together will solve it.

Although the cadillac man speaks the truth above, I like to start with the inexpensive fixes first.

Othniel13
11-05-12, 04:48 PM
jnrsesv thanks for the reply. No explanation given why the OBDII will not read. Both Oriellys and Autozone seemed rather stumped as to why it does not work. Neither had ever seen it before. just no connection at all. I did find a switch of some sort in the driver side foot well but it has a connector and is not attached to anything. I am thinking that maybe the previous owner had a remote start or maybe an amp...

The Oreilly guy did a pretty good once over of the battery checking the cells with the meter, although I am not sure how they can do that. It is a 700cca battery but not sure about the date of install, will check on that. Starter also checked out fine.

I am going to remove some fuses tonight and see if I get any changes. Also going to dig out my own meter and start looking for answers. Just wanted to find some ideas since this car has been a string of issues, although I have been successful with the other issues so far and it is so much easier to work on than the european cars I have been wrenching for the last 10 years.

the cadillac man
11-05-12, 06:52 PM
jnrsesv thanks for the reply. No explanation given why the OBDII will not read. Both Oriellys and Autozone seemed rather stumped as to why it does not work. Neither had ever seen it before. just no connection at all. I did find a switch of some sort in the driver side foot well but it has a connector and is not attached to anything. I am thinking that maybe the previous owner had a remote start or maybe an amp...

The Oreilly guy did a pretty good once over of the battery checking the cells with the meter, although I am not sure how they can do that. It is a 700cca battery but not sure about the date of install, will check on that. Starter also checked out fine.

I am going to remove some fuses tonight and see if I get any changes. Also going to dig out my own meter and start looking for answers. Just wanted to find some ideas since this car has been a string of issues, although I have been successful with the other issues so far and it is so much easier to work on than the european cars I have been wrenching for the last 10 years.

There is a fuse somewhere that supplies power to the obd port other then that it is a network issue

Also check the battery connections on both the cables and battery as it can corrode over and cause some issues.

Othniel13
11-06-12, 01:14 PM
Ok so here is what I found...

Every fuse was good execpt the fuse that runs a few of the back accesories (rear heated seats among others was blown).

I did see that someone spliced into the purple wire on the OBDII port for something that is no longer there. I will check those connnections and bring it back up to somewhere.

I pulled all fuses except those that I need to drive the car.... so only major systems and heat for the front.... ran the car for 10 minutes then let it sit overnight.... still started very hard this morning. It was cold here in Cleveland but not sure that has any bearing.

So tonight going to take out the fuse for the BCM and PCM and see if I get similar results.

Anyone else have any other ideas? I really think cadillac man is on the right course with the PCM/BCM the more I think about it.

the cadillac man
11-06-12, 03:41 PM
Ok so here is what I found...

Every fuse was good execpt the fuse that runs a few of the back accesories (rear heated seats among others was blown).

I did see that someone spliced into the purple wire on the OBDII port for something that is no longer there. I will check those connnections and bring it back up to somewhere.

I pulled all fuses except those that I need to drive the car.... so only major systems and heat for the front.... ran the car for 10 minutes then let it sit overnight.... still started very hard this morning. It was cold here in Cleveland but not sure that has any bearing.

So tonight going to take out the fuse for the BCM and PCM and see if I get similar results.

Anyone else have any other ideas? I really think cadillac man is on the right course with the PCM/BCM the more I think about it.

I doubt it is the bcm more likely the PCM unless you have issues with stuff like your lights or radio as they are controlled via the bcm here is a list

Interior and exterior lighting(except brake lights and flasher/turn signals)
Front and rear hvac systems
Locks
Windows
Gauges via signal from PCM
Radio and amp(also auto volume via signal from PCM)
Rear seat entertainment(if equipped)
Sunroof via module
Seats
Remote keyless entry via data bus to passenger door module
Auto headlights and headlight delay
Courtesy lamps(puddle lamps and perimeter lighting aka drls and back up lamps)

The PCM works everything under the hood
Even the charging of the battery via signal to alternator and is the main module on the data bus (I know as when mine failed it took the data bus down with it and the dealer couldn't communicate with it with the tech-2 until after replacing the PCM

Ps I have wiring diagrams for our trucks if you want I can see what the purple wire is for.

Othniel13
11-06-12, 03:50 PM
Cadillac Man.... thanks for the help. This makes sense since the car I had before this was a 03 BMW 540 that had damage to the BCM and the interior lights and keyless entry stopped working, among other odd things... Not anything like the issues I have here. Everything works fine except that I can't read from the OBDII and the battery is drained. The battery drain is much more frequent now more than ever...

I will pull the PCM fuse tonight and see how the battery holds out and report back so others can learn from us. hopefully my battery and alternator has not been killed by all of this.

the cadillac man
11-06-12, 05:00 PM
Cadillac Man.... thanks for the help. This makes sense since the car I had before this was a 03 BMW 540 that had damage to the BCM and the interior lights and keyless entry stopped working, among other odd things... Not anything like the issues I have here. Everything works fine except that I can't read from the OBDII and the battery is drained. The battery drain is much more frequent now more than ever...

I will pull the PCM fuse tonight and see how the battery holds out and report back so others can learn from us. hopefully my battery and alternator has not been killed by all of this.

Battery maybe alternator doubt it as mine would have died after my PCM so have the battery tested after getting the PCM replaced

Ps I had a 99 Chrysler Concorde nice car bad electrical (I think both PCM and bcm was bad in that car as the battery would get overcharged worst two years with a car I ever had(and the last Chrysler I will ever get) I have a 79 Chrysler cordoba great solid built car(Mercedes ruined them when they had Chrysler)
Ps I may put a gm power train in it should something happen with the engine or transmission

EscaladeLady
11-06-12, 05:11 PM
I have an issue with my 2003 the engine light comes on it every so often then just goes off

amtrucker22
11-06-12, 09:21 PM
The fuse that typically affects the odb is the cigar fuse under the hood (15 amp I think).

the cadillac man
11-06-12, 09:55 PM
The fuse that typically affects the odb is the cigar fuse under the hood (15 amp I think).

I know this may sound crazy but if a module on the data network goes down(aka fried or failed) unless it is a minor module it can and will cause data network issues(eg one or both data streams go down)

when my pcm failed it knocked out the streams for the tech-2 but not a regular code reader(that's how I found out the data network connection for the PCM to tcm had failed caused by a internal short in the PCM (everything in the cab of the truck worked yet the service manager couldn't even get the tech-2 to communicate with stuff like the radio, onstar the hvac controls which was working fully at the time and there was no fuses blown

FYI fuses only protect against shorts in the wiring or excessive power draws.

amtrucker22
11-07-12, 09:52 PM
I know this may sound crazy but if a module on the data network goes down(aka fried or failed) unless it is a minor module it can and will cause data network issues(eg one or both data streams go down)

when my pcm failed it knocked out the streams for the tech-2 but not a regular code reader(that's how I found out the data network connection for the PCM to tcm had failed caused by a internal short in the PCM (everything in the cab of the truck worked yet the service manager couldn't even get the tech-2 to communicate with stuff like the radio, onstar the hvac controls which was working fully at the time and there was no fuses blown

FYI fuses only protect against shorts in the wiring or excessive power draws.

Understood. Just pointing out that typically if your odb can not be read due to a fuse, it would probably be the one I mentioned above.

Esco04
11-07-12, 10:40 PM
One thought: Aftermarket car alarm systems use databus modules that require a tap into the purple OBD wire. Possibly your truck had a car alarm system installed at some point, & it was removed before you bought it. These alarms are also spliced into the starter wires, maybe when the system was removed some of the wires were not reconnected securely.

the cadillac man
11-07-12, 10:51 PM
One thought: Aftermarket car alarm systems use databus modules that require a tap into the purple OBD wire. Possibly your truck had a car alarm system installed at some point, & it was removed before you bought it. These alarms are also spliced into the starter wires, maybe when the system was removed some of the wires were not reconnected securely.

That can be possible

jnrsesv
11-07-12, 10:56 PM
+1 on Esco04 and the cadillac mans posts.

I do know that on another marques website I belong to, aftermarket alarms and remote starters are nightmares to track down on these sophisticated electrical systems.

the cadillac man
11-08-12, 01:53 AM
+1 on Esco04 and the cadillac mans posts.

I do know that on another marques website I belong to, aftermarket alarms and remote starters are nightmares to track down on these sophisticated electrical systems.

And a pain to fix should something need replacing

Esco04
11-08-12, 07:25 PM
One thought: Aftermarket car alarm systems use databus modules that require a tap into the purple OBD wire. Possibly your truck had a car alarm system installed at some point, & it was removed before you bought it. These alarms are also spliced into the starter wires, maybe when the system was removed some of the wires were not reconnected securely.
Add: I'd suggest checking continuity of the purple wire at the OBD socket, in case the "un-installer" yanked on the wire while taking it off & damaged the connection at the socket. Also check the starter wire that goes to the ignition switch for damage, if I recall it's a yellow wire. That could account for the intermittent problems you're having. Hope that helps!

the cadillac man
11-08-12, 08:19 PM
Add: I'd suggest checking continuity of the purple wire at the OBD socket, in case the "un-installer" yanked on the wire while taking it off & damaged the connection at the socket. Also check the starter wire that goes to the ignition switch for damage, if I recall it's a yellow wire. That could account for the intermittent problems you're having. Hope that helps!

You are correct on the wire colors