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Randall C
Randall C, ASE Master Tech
Category: Jeep
Satisfied Customers: 12803
Experience:  ASE Master Tech, L1, Jeep owner, Shop owner
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I have a 97 Cherokee 4.0 auto 4wd. Just bought it drove it

Customer Question

I have a 97 Cherokee 4.0 auto 4wd. Just bought it drove it home ran it for half hr shut it off wouldn't start back up. Cranks but no start. Fuel pump doesn't prime, no power to the coil. Figured crank sensor replaced it and still nothing. Checked all my grounds and fuses all good. Need help!!!!!
Submitted: 1 year ago.
Category: Jeep
Expert:  Jerry replied 1 year ago.

Hello and welcome. My name is ***** ***** you for visiting the site.

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That is normally the ASD relay if the fuses are all good.

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If you accept my additional service request for your email address, you can give me your email in a private info box and I'll send you the test instructions for it and location of it, along with a wiring diagram in a PDF file, the file is rather large.

You will just have to accept the additional service offer and ENTER your email address in the “ENTER CONTACT INFO” section so that I can see it, Thanks

Customer: replied 1 year ago.
My ASD is not clicking nor my fuel relay. If I jump the ASD I get power to my coil but still no fuel pump. But if I jump the fuel pump as well it does work. But still won't run. I am thinking my ecm is junk?
Expert:  Jerry replied 1 year ago.

I see, thanks. That is possible but, just to be sure, are there any after market security systems installed on it?

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Do you get spark to the plugs when the relays are both jumped out?

Customer: replied 1 year ago.
Plug in code reader and it says no communication. When I turn the key on it does not flip the gages or show the volts or fuel level. It is a sport model with crank windows and manual locks. I tried unlocking and locking the doors just in case but there is no red security light anywhere.
Customer: replied 1 year ago.
No spark when I jump the ASD either. And I do have constant power to the ecm and when I turn the ignition on another wire sends power to it
Expert:  Jerry replied 1 year ago.

That is probably something that is not as bad as it appears. However, I have never run into that on one of them, (yet) and I don't want to condemn the PCM just yet. Please allow me to step out and see if someone else may have encountered that on any of them. Thank you for your patience and sorry I was not able to help get it fixed for you.

Expert:  Randall C replied 1 year ago.

Hello, I am Randall, Do you have a testlight? how are you confirming power to PCM? does check engine light come on with key to RUN?

Customer: replied 1 year ago.
I have a test light and I checked the power to ecm thru one of the plugs. And no there is no cel on the dash when turn the key on or gages moving
Expert:  Randall C replied 1 year ago.

ok, to backup, the check engine light does NOT come on with key on like it should? do you have wire colors at PCM you checked for power?

Customer: replied 1 year ago.
The check engine light does not come on when I turn the key to on. And none of the gages read either. I cannot remember the color of the wires that had power to the ecm but I can tell you tomorrow.
Expert:  Randall C replied 1 year ago.

im not going to be online good bit of day on Friday, I really need you near vehicle so since our schedules will differ, I suppose I too will opt out, I cant send the answer without a couple tests, I am sorry

Customer: replied 1 year ago.
Thank you for trying. I am just trying to figure out a definitive way to determine if I have a bad ecm without paying 150 bucks to find out.
Expert:  Randall C replied 1 year ago.

ok let me do this, best I can do without tests. the lack of running, lack of CEL and other symptoms? you have one of a couple things.

Yes, PCM could be bad but rare, so,, in one connector at the pCm are 2 wires, you need to unplg, turn key ON and probe the Dark green/black and the Dark blue/white wires

if missing power on any? you have a power supply issue and likelya fuse or wiring to the PCM so

In the under hood fuse box, be sure to swap out fuses 18,20 and 21, AND swap fuse #11 in theinside fuse box

If you have power to BOTH the dk blue/white and.. the dk green/balck at the PCM? with key ON? then you have a bad PCM

Expert:  Randall C replied 1 year ago.

here is a link to to the power /grounds to the PCM as well as oter powertrain diagrams, focus the power supplies only , the CEL is the clue the PCM is not powering up OR you have a power problem to the PCM

Customer: replied 1 year ago.
OK don't drop out I'll get back to you after I try it tomorrow and let you know.
Expert:  Randall C replied 1 year ago.

its the best i have, I have sent all the diag info there is persay, You have to take from here, LMK