So been having some issues with my Uplander lately... Abs traction and stabilitrack warnings popping up when humid / heavy rains, and at idle at ( 600-700 rpm...which seems kind of low for a engine idle speed should be more like 750- 800?) the engine seems like it's bucking like misfire but with no codes and my serpentine belt will squeal for a second... Also does this bucking thing at higher speed... Like at 90 - 100 kph... Mostly only when it's humid... When cool and dry outside it doesn't seem to have any issues at all. Abs traction control all seem to kick in when they are supposed to.

A few weeks ago and once recently when it was foggy I'd try to start the van and nothing would happen.. I'd hear a relay in the fuse panel click but no start... Not even a dim in the headlights but after a few tries and a few minutes later she would start up fine.

I think there just could be some grounding issues with moisture in the plugs for abs sensors and maybe a bad spark plug wire causing the spark plug not to fire fully? Or is it the alternator skipping a beat making the belt skip and plug not to fire from the voltage drop? (bit of a chicken and the egg dilemma).

I have a appointment with the mechanic scheduled and am thinking of getting battery, alternator, belt and spark plugs all checked along with the abs wiring for any bad connections etc. Just looking to see if I'm doing the right thing or not. Thanks in advance for any pointers you guys may have.

 

I had a bad positive battery cable on my 08 Uplander which gave all the symptoms you mention accept the miss. This cable has to wires. One of them goes fuse box. This wire would ohm intermittently open when I would flex it.

 

ABS wiring is always suspect in these vehicles as they are a well documented weak spot...ABS, traction, etc warnings show up when the sensors readings' are so different that its not physically possible. Could happen at idle or while driving at any speed. Its likely that a bearing/sensor or the wiring harness will need to be replaced.

As for the bucking, etc, I would not be surprised if you have an ignition module which is failing...you don't mention how many miles you have so its hard to say...

Did you check the codes with a reader or are you relying on the DIC to tell you? Typically misfires are recorded by the PCM even if you don't get a check engine warning light.

I wouldn't tell the mechanic what to check but would just explain the issues to him/her. I don't know of bad grounds being an issue on the Uplander but if your battery is as old as the van its likely it needs to be replaced. These things are really sensitive about system voltage and if you're running a bit low it can cause issues. Just some random ideas...good luck...