compass no rear wiper

gfbidd

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#1
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MAKE: jerp
MODEL: compass
YEAR: 2008
MILES: 150,00ish km
ENGINE: 2.4
DESCRIBE ISSUE....rear wiper wont work, washer does, fuses are good, ignition power and ground at motor, no power from TIPM
 
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#2
"jerp" ? LOL

I looked for info for testing rear wiper switch, but found nothing helpful. Switch probably closes a circuit which includes a specified resistance to let a module know what you want to happen. (e.g. 450 ohm signal tells module you want rear wiper to operate until signal is removed, changed, or repeated.)
 

nickb2

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#3
So assuming you have ignition voltage on pk/yl wire, ground is good on bk/lb, no signal on br/lg for wiper control from integrated power module, next logical step is to pin test that wire for an open.

At the same time, it will push you to turn over the TIPM and see if there is any corrosion underneath there. A very common issue for the Jerps, or any other chrysler product of this era.

If no issue is found there, then sadly this will need to have the use of a proper scanner to test this issue out since the problem now resides in the CAN bus network. At this point, it could be the SCM or the EMIC or the TIPM module itself. Also, even if the switch itself is sending juice to the washer pump, doesn't mean the switch is good for the motor portion of this circuit. This is what they call a control sleeve function test. Screenshot (135).png

Since this is a compass, I don't think it has a opening rear window for the liftgate like a grand cherokee, but I can't recall if that was an option or not and I have never seen a compass equipped with that. Alldata is not showing one so I don't think so. But if for some reason it does have a opening rear glass, check that. If the TIPM is seeing rear glass as open, it will not ground the logic can bus circuit to operate the motor.

So, resuming, to properly check most of this, you will need a bi-directional scanner, but trying to pull codes is always a good thing, you may find codes with a "U", "C" or "B" prefix that may help pinpoint the problem.
 

nickb2

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#4
This is where a proper scanner shines, you can see all the inputs and outputs which helps greatly. Sadly, not widely available. But if you know anybody that has a bi-directional scanner, I would highly suggest you use that.

But to repeat myself, start by looking under that IPM. You will be surprised at how many gremlins start there and you may also prevent further gremlins when you see all the corrosion that builds up on the contacts and printed circuit board.
 

nickb2

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#5
As an after thought, you could also try a TIPM hard reset. Never know, free to try and non invasive.

I had a particular problem in my bay a few weeks ago. A reset of the IPM did the trick. The rpm would fluctuate at 40-60 when coasting and sometimes would stall or fluctuate at idle. The scanner at idle showed neg spark advance which is not normal. All pointed to a sticking electronic throttle body. I cleaned that and still had same problem. So I then thought it was the internal IAC which comes with a new throttle body.

Found a TSB from mazda stating that indeed, if this symptom was present, and spark advance was as mine, to not replace the throttle body before trying a reset of the IPM. Which I did. Spark advance immediately went back to normal, gone was the problem. If problem then presented itself again, only then suspect the electronic throttle body. Have not seen the client back yet. But if I do, I will then be sure of my diagnostic and only then will I replace that expensive part.

A reset is easy enough to do. Same applies for most IPM's. Disconnect the positive lead/s of the IPM and ground for 10 mins. Done.

Another example of where a reset fixed a lighting issue. A light bulb had shorted the circuit. TIPM and BCM went into protection mode. Replaced bulb, still no light. Reset the IPM, bingo, let there be light. So maybe if a reset shows movement of the motor, then you may be onto an intermittent short and the module is just in protection mode.

Hoping what I just wrote made sense to you.