Jacob Vaughn

Alright so I got a 2000 Jeep Cherokee 4.0. Ive been getting this code P0201- Injector circuit open/cylinder 1. Changed the Injector with 4 different injectors an still getting the code. Checked the pigtail with a multimeter. Getting 13.87 volts along with #2-#6 Injectors. All of them are getting 13.80-13.87 volts (they vary). Anybody ever had this issue? I've read up an checked everything I know. Also chased the wires an only found 1 bad spot on 1 wire an it looks like it just got pilled by a knife. No broken visible wires. Taped it up an put everything back together. Also have checked the pins in the ECM an they're good. Is my ECM burnt up or what? Need it fixed asap!

awg

If you are able to verify the Injector is not working, with a noid light, or by listening to it click with a mechanics stethoscope, then you need to verify continuity of the wire & connectors back to the PCM, as the PCM grounds the Injector every pulse

97grand4.0

Any other codes with it??
You didn't say if it's actually misfiring?

Dave51

I doubt that the ECM (PCM) is "burnt up" per se, it's probably just the driver for that injector, which I believe is a 43U02 chip. You got electronix solder skilz?

Jacob Vaughn

i have stick a small long bolt to the side of each Injector, 2-6 feels like they are tapping. 1 done nothing. I do not have a niod light but I just put my muiltmeter on it an the volts are jumping from 13.60-13.75/80 so it's getting palse. I have traced every wire back to the PCM an there was only 1 bad spot on a wire. An it looks like it had rubbed down to the the wire. But no broken wire. It was a green an orange wire so it's a ground wire. Also, when this probably started happenin, my CPS broke. I changed it an got it runnin where it had its power back but don't have everything it had before.

Jacob Vaughn

i have no clue how to soldier anything so that's out of the question for me😂 if just swap the PCM an run it if that's my problem.

Jacob Vaughn

Yes, when I unplug the #1 Injector, it does absolutely nothing to the way the motor runs. The other code is for the battery tray temp sensor I don't have in. And I know that is not my problem do to me not Havin a battery tray for the last 2 years. 😂

Dave51

That only tells half the story. The pulse is actually determined by the driver on the ground side, so if the injector is good, and the wire to the PCM is good, and you have power, then the the problem is in the PCM. Either the driver is bad, or the pin for the driver is bad.

The driver probably costs about 10 cents (although you usually need to buy like 10) and resoldering a broken pin is essentially free (although it's about 20 bucks if you need to buy the tools(although tools is not an expense, it's an investment).

Dave51

That's why when you buy a reman they want the old PCM.

lawsoncl

Measure from the pin at the PCM to the injector connector and see if the wire is broken. It's not unusual to have the wiring in the harness where is goes from above the intake manifold to the firewall damaged or broken internally from the flexing.

Dave51

How'd you make out with this?

jglz2594

Did you ever get this fix, i have a 2001 that i just developed the same problem P0201!

jakegroove

Adding on to the thread brought back from the dead:

https://thegrovecollaborative.com/p0...it-faulty-ecu/

Put together a brain-dump of an article after going through this twice.
P0201 Repair - for those that need it.

CheapTrekkingDotCom

Fixed! P00E3, P0500, P0505, P0201, P0202, P0203, P2301, P2302, P2303, P1494.
I signed up to this forum just so I can share how excited I am. My son's 2004 Grand Cherokee 4.0L has been running like garbage. Unsafe to drive. Sputtering and hesitating to almost stalling out on the highway or residential. It's been parked for 6 months as I tried to figure out what is wrong. I replaced the coils. No significant change. Idle Air Control Valve, nope. OK so might as well change the injectors. Nope. So maybe I got a couple of bad cheap injectors tried a few more. Nope. I just can't admit defeat and take it to dealer. Bought fuel injector tester gadget and replaced one more injector, now all good. Nope. Bought noid light set and it pulses on all 6 injectors. Still smoking fuel rich sputtering crap. I skipped work today it's my 30th wedding anniversary. I said today is the day I fix this or drive it to the dealer. My bluetooth scanner gave me every code listed above. I got rid of the P1494 by replacing several rubber elbows. Cleared the codes and they all came back except the P1494. Took a nap. A long nap. Started googling fuel injector wiring diagram. A link to a video about missing insulation causing injectors to vapor lock at normal running temp. I thought no crappin way but what would it hurt. Got some aluminum foil from the kitchen and crafted a pure redneck heat shield to see if anyway possible. I'LL BE DANGED. Jeep drives like brand new and none of the cleared codes returned. I can't explain how happy I am. Your results may differ, but what have you got to lose? I swear my JEEP had every code listed above this morning and they all seem to have been because of missing heat shield. How did it go missing? Well I must admit I may have initially had 1 bad injector and when I replaced them all I know I threw some of it out because it was damaged. I never dreamed how fateful that decision would be. Oh well. Sorry for this long post. Maybe it's been helpful. Maybe entertaining. Peace.