Do you own a multimeter?

 

Yes have both analog and digital meters. Pretty sure prob is on pin 30 of asd. On this van I get 1.3v on the 2003 I get ground. Was thinking of clipping at PCM and checking output there. What do you think?

 

Well, yeah I have to admit I clip sometimes. Sure beats the hell out of opening up the whole harness for a quick check. I wouldn't do that just yet though.

Pull the ASD relay out. Switch on....86 and 30 should have battery voltage. They are fed by fuse #16 - 25 amp. If 30 is low then you have a splice issue inside the IPM.

 

I have seen 2 different diagrams for this circuit and it appears to be like this one that I found on another thread w/ this topic, see attachment.

This shows batt+ on 86 & 87, which I definitely have 12.1v on these, same on the 2003.
Last night I checked the PCM grounds again and got continuity to grd at the conn. At 50 bk/dg and 10 bk/br. Should I run a jumper to grd to make sure? Also, is S111 the ignition sw?
The guy that changed the PCM last year came out to look at it at my place yesterday said he’d have to take it to his shop, put told me he’d check the FCM on the fuse block. Can’t tell if this comes apart but I think I’m gonna swap in the whole IPM from the 2003, hope it’s the same part.
Considering towing it to the closest dealer and having them run diag. For $86. Will their equipment redily find this problem?
Someone told me it could be security sys too, not familiar enough w/ this to know about it.
I’m more than willing to check anything on this vehicle, I’m lost w/o a diagnostic book right now, but if you can guide me thru it I’ll do my best!

 

Got the vehicle scanned w/ the Chrysler tool. "Bad communication link w/ PCM", everything else read ok. Talked to the guy that changed the PCM last oct., said he can get another on warranty. Cool, this is takin wayyy too long tho, need to get it out of my garage, should have it in this weekend.

 

Just a follow up on this that I never posted. The PCM was bad. I think the best sign of this was that the code scanner showed a lot of data as "n/a". After putting in the new PCM and having a guy from a dealer come out & flash it w the bcm it has been running fine.

 

Awesome sir. Thank you for following up. Come back when you need help again. We're here 24/7, except when we're not

 

Just finished troubleshooting this problem on a 1999 Caravan (edit). Solution was ground and corrosion problems. The main culprit was the battery negative terminal clamp. There is the main thick battery wire to the block and a second small ground wire for the ecu. The battery terminal clamp was corroded enough that even though the screw clamped securely, there wasn't good electrical contact with the ecu ground wire. I wire brushed the clamping screw, terminal clamp and the ecu ground wire terminal until they were shiny. There is also a ground strap that snaps on at the passenger side engine mount next to the pulleys. It jumpers the engine mount - electrical connection between the block to inner fender. The connections were corroded. I cleaned it up and then added a second backup ground strap between the engine block and the fender. Put it all together and everything was fine.

I believe the chattering is because there wasn't enough voltage going to the relays to engage them or the ecu was detecting a low battery condition even though I had a new battery installed. One very strange symptom was that the van would start up immediately when boosted (edit) but as soon as the ground jumper was removed, the engine died and the relays started chattering.

 

Grounds are a big problem for 2001 to 2007 vans on the left side and front. Also battery corrosion rolling off onto the main harness and creeping in over time. Of course when a vehicle is 18 years old, all bets are of really.....

 

Some of the crazy symptoms were:

• throwing no ECU error codes when running,
• Sometimes the starter would just click - solenoid energized but starter wouldn't turn over - I thought that it was a bad starter at one point because the battery voltage would measure 12.6V when trying to start
• Sometimes the starter would continuously click like a low battery
• ASD relay would chatter like crazy for 30 seconds when battery was initially connected without the key in
• Boosting the new battery would cause the engine to start up immediately, disconnecting the boost ground jumper would cause the engine to die
• Sometimes the engine started fine