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2004 jeep grand cherokee 4.0 open circuit injector cylinder 1
Im new here. do bear with me. im getting a p201 code . i pulled the wire on injector 1 hooked a test light to it. all the other injection plugs flicker #1 just stays on I traced the wire back to the pcm driver its a white/blue wire I checked it at the pcm with a test light .clip on the test light on the pos and probe on the white/blue wire with the engine running it stayed solid. i then clipped the wire tested white/blue wire at the pcm with the test light. its still solid. I tested the clipped wire to the injector for a ground short it seems to be fine . i then hooked the wire back up and plugged it into another injector a loose one same result. solid light i then probed the yellow white wire next to it suppose to be the control for cylinder 3 it is flickering as expected. the feed wire is fine. at this point im drawing a conclusion that the pcm needs to be replaced. but wanted to ask am i missing something?
I understand that you cut the white/blue control wire of injector ·1 at the pcm. With a test light hooked up to B+ with the engine running the light stays on all the time when you connect the tip of the test light to the part of the cut white/blue wire that connects to the pcm. If this is true then yes, the driver for injector nr.1 is shorted to ground.
An expert is someone who knows each time more on each time less, until he finally knows absolutely everything about absolutely nothing.
Last edit: 3 years 11 months ago by juergen.scholl.
thank you so much i was afraid i didnt explain it enough. but you understood exactly. one more quick question on this model does the pcm need to be flashed or can i pick one up at a salvage
The pcm does not need to be "flashed" in the sense of programing the calibration/maps into it.
BUT: you will have to "marry" the new pcm to the immobiliser. This basically is writing the vehicle identification number of your car into the pcm. To do so you´ll need a capable scanner, the secret (4 digit) immo pin of your car and - preferably - of the donor car.
An expert is someone who knows each time more on each time less, until he finally knows absolutely everything about absolutely nothing.
The easiest way is a capable scantool which can read the information from the skim module (immo unit) and/or pcm, another is reading the eeproms of these modules directly. If you're not familiar with these procedures or lack the tools your best bet is a locksmith.
An expert is someone who knows each time more on each time less, until he finally knows absolutely everything about absolutely nothing.
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