Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!

Auto shutdown issue

More
6 years 2 months ago - 6 years 2 months ago #16740 by Mort
Auto shutdown issue was created by Mort
working on an 03 dodge grand caravan 3.8 cranks no start. finally got the service manual from Mopar. looking at the schematic I should have voltage potential at circuit 86 and 87. The 25a fuse is good. I have no voltage at 86 which should energize the relay. Am I correct in assuming that 86 and 87 are on the same wire coming out of the fuse? I have no ref voltage at the TPS which i am guessing gets voltage from the ASD relay. I checked circuit 85 which should be the ground side of the circuit and have good continuity to ground. What could be keeping the voltage from getting to 86 is it safe to jump 30 to 87 to see if the vehicle will start and run?
Last edit: 6 years 2 months ago by Mort.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16743 by Tyler
Replied by Tyler on topic Auto shutdown issue
Hey Mort! I did a quick edit of the title for clarity. ;-)

So you're testing at the ASD relay, correct? I had a look at the wiring diagram:



For our info, are you using a DMM or a test light? It looks like, KOEO, you should have voltage at pins 86 and 87 of the ASD relay socket. If Fuse #16 is good, but you don't have voltage on either of those pins, then that would suggest an open wire or a pin issue inside the IPM. You COULD jump between pins 87 and 30, but only if you're absolutely positive that you're jumping the correct pins, and that pin 87 actually has power like it should. I'd suggest waiting on jumping the relay until we have a better understanding of what's missing for the relay to work. ;-)

You've checked all pins at the TPS, and didn't find anything? That would suggest that the PCM isn't working, as it's the source of the 5V reference that the TPS uses to create signal.
Attachments:

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago - 6 years 2 months ago #16754 by Mort
Replied by Mort on topic Auto shutdown issue
Thanks for the quick reply. Ya I pulled 16 and have continuity between the negative side and 87 but nothing on 86 which has me stumped I flipped up the Ipm to see if any wires were broken and they were ok. This is the van that had the wiring in the wheel well ripped up by the blown tire. I thought the TPS got energized through the ASD relay I'll recheck the TPS and get back with you.
Last edit: 6 years 2 months ago by Mort.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16758 by Tyler
Replied by Tyler on topic Auto shutdown issue

Mort wrote: Thanks for the quick reply. Ya I pulled 16 and have continuity between the negative side and 87 but nothing on 86 which has me stumped


Really? :huh: That's pretty much down to an IPM issue, then. Or the wiring/connections in it, anyway. You could verify this with a test light connected to B- on pins 86 and 87. If one lights but the other doesn't, then you've found the problem.

You could also partially install the relay (with the pins exposed), and connect your test light to B+. Touch on pin 86 and see if the relay now operates during cranking.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16769 by Can Bus
Replied by Can Bus on topic Auto shutdown issue
I will have to say if you have B+ on 87, and nothing on 86, then you need to find that splice. Suspect you have a broken wire between the splice and 86. Or the terminals are corroded, causing a bad connection. Are you sure the relay is good? Try swapping relays with a known good relay.

There Is No Such Thing As A Stupid Question, If It's Sincere. Better To Ask And Risk Appearing Stupid Than To Continue On Your Own Ignorant Way And Make A Stupid Mistake. Author Confidential/Unknown

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16776 by Mort
Replied by Mort on topic Auto shutdown issue
Ya Joe I have checked every relay they are all good

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16780 by Dave101
Replied by Dave101 on topic Auto shutdown issue

Mort wrote: Thanks for the quick reply. Ya I pulled 16 and have continuity between the negative side and 87 but nothing on 86 which has me stumped I flipped up the Ipm to see if any wires were broken and they were ok. This is the van that had the wiring in the wheel well ripped up by the blown tire. I thought the TPS got energized through the ASD relay I'll recheck the TPS and get back with you.



Yeah Mort, I agree with Tyler. Continuity test are ok but I prefer a voltage check on most circuits. I have seen some continuity test show good only to prove themselves wrong. Good Luck

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16789 by Mort
Replied by Mort on topic Auto shutdown issue
I have checked voltage at both 86 and 87 no voltage at 86 I haven't removed any of the plugs going into the IPM if I unplug everything wouldn't that isolate the problem to the IPM. I repaired all of the wiring in the wheelwell and that gave me back the power in the cab.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16791 by Tyler
Replied by Tyler on topic Auto shutdown issue

Mort wrote: I have checked voltage at both 86 and 87 no voltage at 86 I haven't removed any of the plugs going into the IPM if I unplug everything wouldn't that isolate the problem to the IPM. I repaired all of the wiring in the wheelwell and that gave me back the power in the cab.


I think you've pretty well isolated the issue to the IPM itself, as the wires that go from Fuse #16 to the ASD relay socket don't leave the IPM (according to the diagram, anyway).

If you can use your test light to provide power to pin 86 and the ASD relay works, then I'd consider either taking the IPM apart and finding that splice like Euro Joe suggested, or replacing it.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16855 by Mort
Replied by Mort on topic Auto shutdown issue
Ok I made a major FUBAR. the ASD circuit is good. I removed the IPM and realized I was looking at what the IPM cover calls the ETAX safety shutdown relay. the schematic calls it the transmission control relay. again I checked the fuse # 15 it is good I have continuity to 87 of the relay circuit and nothing at 86. looking at the schematic i see that voltage comes from the TCM with the IOEO If I am reading this right I should have voltage at 86. now I am thinking I have a bad wire between the TCM and IDM. yay or ney.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16875 by Tyler
Replied by Tyler on topic Auto shutdown issue
:lol: No problem! At least you realized what happened before you swapped the IPM, or started cutting wires.

Again, looked up the diagram for reference:



Now, at this point I feel it necessary to point out that a problem with the transmission control relay won't cause a no start. Don't get me wrong - I'm totally happy to help you chase down this relay issue! :cheer: But if the engine isn't starting, then I think we need to back up and attack this from another direction.
Attachments:

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #16882 by Mort
Replied by Mort on topic Auto shutdown issue
Ok Tyler where do you suggest I start? I haven't reinstalled the IPM so I can check the wiring from it if need be, but I do want to check the wiring going to and from the IPM, TCM, and PCM since the blown tire thrashed the wiring in the wheel well around the TCM. I did buy a cable tracer from Harbor Freight to hopefully help make things easier.
The following user(s) said Thank You: Hitekrednek86

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #17092 by Tyler
Replied by Tyler on topic Auto shutdown issue
Hey Mort! Still working on this one? Sorry it's been awhile since I responded.

How's spark and injection pulse? That'd be the place to start. Or, at least power to the ignition coil and injectors during cranking. If you have both, then you can add carb clean to the intake and see if it'll start/run.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #17108 by Mort
Replied by Mort on topic Auto shutdown issue
Figured you were busy Tyler. yes I am still working on it not getting any voltage on the TPS no spark from the plus when cranking only getting .15 volts from the #2 position on the ignition coil wire when cranking. MAP sensor has 4.1 6.75 and 6.70 readings Right now I am clueless as to the problem. I am leaning towards the PCM, but want to be sure before I tell the owner. all I have to test with is a light and a multimeter.

Thanks

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago - 6 years 2 months ago #17128 by Tyler
Replied by Tyler on topic Auto shutdown issue
Your TPS and MAP sensor readings are very strange. :ohmy: I could understand how the TPS would have no voltage, but those MAP numbers are difficult to account for, especially because the TPS and the MAP get their 5V source out of the same PCM pin.

I say stay with the lack of power at the ignition coil. Back up that reading with a voltage check at pin 1 at C102 of the fuel injector harness during cranking:





If you still have no power, then we need to go back to the ASD relay. If we're sure the ASD relay is working, then we can trace a wiring problem in between.
Attachments:
Last edit: 6 years 2 months ago by Tyler.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #17140 by Mort
Replied by Mort on topic Auto shutdown issue
Tyler I have rechecked the ASD relay. I have voltage at 86 and 87. I tried your suggestion of leasving the pins of the relay exposed and checked the voltage IOEO seems the ground side 85 has an open I then grounded my test light and made contact with the 85 side of the relay and it energized I am assuming this is grounded by the PCM Haven't checked the wire to the PCM. correct me if I am wrong, I should be able to check between 85 and pin 67 of C2 at the PCM for continuity..

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #17146 by Tyler
Replied by Tyler on topic Auto shutdown issue
KOEO and you're seeing 12V at pin 85 of the ASD relay? That's normal, as the relay isn't grounded with just the key on. The engine has to be cranking (or running) for the ASD relay to get energized.

If you still don't see a ground at relay pin 85 during cranking, then absolutely, go to pin 67 of C2 and recheck during cranking. :cheer:
The following user(s) said Thank You: Monde

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #17158 by Mort
Replied by Mort on topic Auto shutdown issue
Ok I will do that first thing in the morning. I really don't understand why I have voltage on all three wires of the MAP sensor.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago #17161 by Tyler
Replied by Tyler on topic Auto shutdown issue
Me neither! :silly: It might suggest a bad ground, but then how is there voltage at the MAP 5V supply, when there's zero at the TPS 5V supply?

I'm thinking that following the ASD issue will bring us back around to the sensor readings you're getting.

Please Log in or Create an account to join the conversation.

More
6 years 2 months ago - 6 years 2 months ago #17193 by Mort
Replied by Mort on topic Auto shutdown issue
I rigged a jumper off of 30 to see if it switched on when the relay energized. I turned on the switch the meter jumped to 12V then dropped to zero. while cranking, voltage went up to .15 if you call that up. shouldn't it be reading 12V at 30 since there is 12 V potential at 87 before energizing the relay don't understand the drop. Checked continuity between 85 at the relay and 67 of C2 at the PCM. As monde stated it seem i am not getting control voltage through the PCM. For giggles I checked the MAP Sensor wiring for continuity to insure the wires weren't crossed from the PCM to the sensor. The wiring is good. Doesn't this suggest a short somewhere in the PCM since I am getting voltage on all three wires?
Last edit: 6 years 2 months ago by Mort. Reason: added content

Please Log in or Create an account to join the conversation.

Time to create page: 0.318 seconds