Cadillac Owners Forum banner

1 - 15 of 15 Posts

·
Registered
04 escalade esv
Joined
·
10 Posts
Discussion Starter #1 (Edited)
RESOLVED! Read entire thread.


I have read so many posts on this issue and have still been unable to resolve this problem. Here is the low down on what it's doing and what I have done.

For about 2 months the escalade would not crank from time to time after being driven. At first, 15 minutes would pass and it would crank and start fine. The time between it not cranking and then suddenly working correct is growing. 2 hours stuck at a restaurant last night waiting for it to crank has me furious with this issue. Temps in Texas got to the high 80s yesterday. When cool outside and in the mornings, vehicle cranks and runs perfect every time. When the engine gets warm after driving, no cranking at all. All lights, radio, windows etc... Work fine.

Things I have done in the last 2 weeks.

1. Tested battery at a parts store. Battery is good and holding proper charge

2. Checked all fluids. All is well

3. Checked cables. No visible corrosion, ground is good. (Verified with multimeter). Also verified with multimeter the alternator, battery at start up, battery while car is off. Removed cables, checked cables with multimeter. No voltage drop.

4. When not cranking, tried moving relays around, relays are working properly but still no crank.

5. Removed starter and took for bench test. Tested ok, but replaced anyway as there was excess rattling in it. (Sounded like rocks were in it). Replaced starter, cleaned cables to starter, reinstalled heat shield on starter.

6. Verified all fuses are in proper working order.

So, I'm fairly mechanically inclined, have basic tools, bought a multimeter and youtubed how to test stuff with it. I can tackle most repair tasks.

Other info: occasionally after it cranks and starts, I can't get the ac to blow cold. (Tested for leaks and pressure, all tested good). If I open the hood when no crank happens, it lessens the time I have to wait. Like it helps the engine cool faster so it will start. Vehicle is great when it runs, up to now I have only replaced the driver side front wheel assembly after it was grinding like crazy.

Escalade has 109,000 on it and averages 12.6 mpg.

What do I do next? How do I check it? There is no definitive answer as all the posts I read say it could be fuel pump (which wines as it should even when it won't crank), bad starter (mine is 2 days old), bad relays (mine check out fine), poor cable connections (mine are clean and reading well on multimeter) burnt fuses (mine are good), bad key, bad ignition, bad key cylinder, pass lock system (mine does not stay on at start up or during no crank issue). This absolutely has to do the the outside temp and the engine being shut off after it has warmed up. Doesn't happen when cold outside though. I'm at my wits end.

Sorry for the long post, I just wanted to be detailed.
 

·
Registered
03 cadillac escalade
Joined
·
11,902 Posts
I wonder if the pcm is the culprit

It does control the starter and the sucurity system section that disables the starter and fuel system

If the pcm is failing it will cause some weird stuff and given how it is a hit or miss but works mostly when it's cool it sure sounds like the pcm has heat related issues

I went through pcm failure and it does disable both whenever one section in it goes nutty(mine had the data bus for the throttle go bad which shorted out the pcm and caused major confusion at my local dealer when I had them repair it)

I had them replace the pcm and all was well

----------

If the cluster button works that brings up your mileage I would call a parts store(advance auto) and tell them you need a pcm and give them the mileage and your vin

I don't know how long it would take but it would be worth a try
 

·
Registered
04 escalade esv
Joined
·
10 Posts
Discussion Starter #4
Shouldn't my check engine light be on though? I'm not a pcm expert by any means, but I have no lights illuminated on the dashboard when driving. I get a change engine oil message (as I do need an oil change) and that is it. No check engine light. I just want to check all possible issues before spending hundreds of dollars on a pcm only to have the same issue. I think I may drop into autozone today and have them run a diagnostic to see if any codes pop up.
 

·
Registered
03 cadillac escalade
Joined
·
11,902 Posts
Not really as the starting system won't cause it to throw a code(been there before when mine failed)

Let me know how it goes though
 

·
Registered
04 escalade esv
Joined
·
10 Posts
Discussion Starter #8
Here is the latest trouble shooting.


Escalade

Ok. I used my test light to check the crank fuse. When I turned it to start, fuse worked and light came on. On both sides of the fuse. Next, I removed the relay and tested pin 30, It is always hot and reads same as battery. Pin 85 had no power. Pin 87 had ground. Pin 86 had nothing. When I put it in the run position, pin 30 and 85 both had power (12.6 on multimeter). Pin 87 maintained ground, pin 86 did nothing. When I hit crank to start, same results as above with 30 and 85 showing a minor power change. Less than .2. If I jump 30 to 87, cranks and starts right up.

I have tried switching the relay with a known good relay, parking lamps. Still won't crank with different relay, but lamps come on with relay I thought may be bad.

Keep in mind, this ONLY happens when it has been running long enough for the engine to warm up to normal temp.

Any new ideas?
 

·
Registered
04 escalade esv
Joined
·
10 Posts
Discussion Starter #9
Chris (aka- Moose)
Cadillac Mechanic
Just to make sure, you did these tests when the car was hot and not able to crank? since 30 has power all the time and when testing pins 85 and 86 one is power but the other not ground, that means the PCM is not grounding the relay, which indicates its your PCM to blame.



02 June 2015 07:42 Yes. I did this when the vehicle would not crank with the key. So pin 86 must go to pcm since it doesn't work when car is in no crank mode correct? If I put my test probe in pin 86 when the car is cranking properly I should get a ground reading right? Does the pcm also talk to the ac compressor or clutch? Cause that is intermittent as well when operating temp hits the 200 mark.

So, if I replace the pcm my issue should be resolved?

Also, thanks for the wiring diagram, that was a huge help!


02 June 2015 07:42 Chris (aka- Moose) Chris (aka- Moose)
Cadillac Mechanic
That's correct when operating correct the PCM should ground the relay coil side.

The PCM also controls the fan and AC.

With the results yes the PCM is to blame.
02 June 2015 07:42


Sooooo, I'm ordering a new PCM next and this "should" resolve all the issues I have.

Thanks for your help.

Also, I have the complete starting circuit diagram, but don't know how to upload it if someone needs it.
 

·
Registered
03 cadillac escalade
Joined
·
11,902 Posts
The pcm works both the electric fans
Along with the ac clutch
Among a few other under hood items(alternator depending on the year)
 

·
Registered
04 escalade esv
Joined
·
10 Posts
Discussion Starter #11
Final update


Installed the new PCM/ECM module today. It came preflashed from flash masters. It was plug and play except for the security system. They sent me instructions on how to have the computer relearn the codes. Took 30 minutes for that part, 10 minutes to replace the computer. All in all, everything works like a dream again. No issues what so ever. Very happy with them.

Also, they sent me instructions on how to reprogram the crank shaft variance if my check engine light came on. I have driven the car all day today and never saw the light. I highly recommend them. And true best part, it was only $95. Seriously! With shipping and everything.
 

·
Registered
'05 ESV Platinum, 250,000 still looking fine, really fine!
Joined
·
1,133 Posts
Cmmsrshal thanks for posting this information up! I am sure it will come in handy for members in the future.
 
1 - 15 of 15 Posts
Top