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Huge Soft top SaleRockridge 4WD IS Taking Zone Offroad Suspension Lift Kits BLACK FRIDAY SPECIALS!! You asked, we deliver!

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Unread 03-13-2014, 05:15 PM   #16
dmill89
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Quote:
Originally Posted by who_datjeep View Post
Great idea, dmill89.

I checked where the yellow wire goes and it goes from what I believe is the TCM(transmission control module) to a module on the left side of the steering column(see picture). Also, I did see a button which may have been a kill-switch and the wires were just cut off from it. See pictures.

Thanks,
Kevin
splice the yellow wire back together (I'd probably cut out all the brown wire except the small length you need to get the yellow wire back together) it may be interrupting the starter.

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Unread 03-13-2014, 06:53 PM   #17
CCKen
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Quote:
Originally Posted by who_datjeep View Post
Great idea, dmill89.

I checked where the yellow wire goes and it goes from what I believe is the TCM(transmission control module) to a module on the left side of the steering column(see picture). Also, I did see a button which may have been a kill-switch and the wires were just cut off from it. See pictures.

Thanks,
Kevin
That top pic is the ignition switch connector C1, The Yellow wire is Fused Ignition Switch Output (Start), which goes through connector C201 to fuse 19 in the JB, from there to the control coil of the starter motor relay in the PDC.

The center pic is what looks like connector C201, not the TCM.
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Last edited by CCKen; 03-13-2014 at 07:18 PM.. Reason: deleted pulling fuse 19.
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Unread 03-13-2014, 07:04 PM   #18
who_datjeep
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Does it look like I am missing a few fuses?



Thanks,
Kevin
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Unread 03-13-2014, 07:11 PM   #19
who_datjeep
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I'll go ahead and reconnect the yellow wire without the brown wire.

Thanks,
Kevin
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Unread 03-13-2014, 07:17 PM   #20
CCKen
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Quote:
Originally Posted by who_datjeep View Post
Okay, thanks for the tips CCKen and CJ7-Tim,

I cleaned all the grounds and cleaned the wires and made sure the battery clamps were properly installed.

I disconnected the SKIM module, still no start. BUT, there is no longer "no bus". The fuel gauge works, though the needle moves a little bit. Of course, no oil pressure, and coolant is cold. Battery gauge shows completely empty, but when I crank it the needle goes even lower. There is sufficient power. The starter cranks good enough and the courtesy lights stay on when I crank.

The relays don't buzz anymore but they click intermittently with the EVAP purge solenoid. The fuel pump still runs continuously as shown in the video.

I took the back cover off the gray PCM connector and looked at all the wires, including C3. There doesn't appear to be anything wrong with the wires.

As CJ7-Tim noted, I didn't think those wire taps and connectors were there on all Cherokees. The previous owner said he hooked up a stereo and then took it out.

Other than taking it to the dealer, what would be next?

Thanks,
Kevin
The last thing you want to do at this point is to take it to the dealer. Besides not wantng to work on a modified vehicle they would charge you a fortune to dianose it.

You seem to be making progress. The relays have gone from buzzing to clicking. But the fuel pump running continuiosly is still an area that needs attention. I think if you found the cause you could possibly fix a bunch of problems.

That fuel pump relay control coil gets its power (12 volts) when you turn the key to RUN, but it won't activate the power contacts in the relay to run the pump until the PCM provides a ground for the control coil. It looks like the relay is getting a ground continuiously. The pump relay will pull in as soon as you place the key to run (prime time) for a few seconds then the PCM will deactivate the relay until the ASD relay is activated, then the PCM will reactivate the relay and it will run continuiously as long as the ASD relay is activated.

Something is providing the relays with a control coil ground.

The problem may be inside the PDC. You may want to look inside the PDC for corrosion at the relay pins/wiring, etc.

Disconnect the battery negative cable.

Pull the small cover off the end of the PDC and remove both cables attached there.

Go to the bottom/outside of the PDC and unlatch the PDC. Raise it up and remove the bottom of the PDC and closely examine all the wiring and relay pin connectors. If you find corrosion it wouldn't be the first time this has happened. Reverse order for putting it back together.
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Unread 03-13-2014, 08:08 PM   #21
MMPerformance
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Quote:
Originally Posted by who_datjeep View Post
Okay, thanks for the tips CCKen and CJ7-Tim,

I cleaned all the grounds and cleaned the wires and made sure the battery clamps were properly installed.

I disconnected the SKIM module, still no start. BUT, there is no longer "no bus". The fuel gauge works, though the needle moves a little bit. Of course, no oil pressure, and coolant is cold. Battery gauge shows completely empty, but when I crank it the needle goes even lower. There is sufficient power. The starter cranks good enough and the courtesy lights stay on when I crank.

The relays don't buzz anymore but they click intermittently with the EVAP purge solenoid. The fuel pump still runs continuously as shown in the video.

I took the back cover off the gray PCM connector and looked at all the wires, including C3. There doesn't appear to be anything wrong with the wires.

As CJ7-Tim noted, I didn't think those wire taps and connectors were there on all Cherokees. The previous owner said he hooked up a stereo and then took it out.

Other than taking it to the dealer, what would be next?

Thanks,
Kevin
I know someone already said that your fuel pump shouldn't be running with the key in the "on" position and engine off which is correct. I had a Dodge Ram do that to me, the camshaft sensor went bad. No start, fuel pump running, on the scanner it looked like the engine was running because the crank sensor was fluctuating from about 280 the 390 rpm, so the pcm thought the engine was running and keep the pump on. I unplugged the crank sensor, fuel pump still on, next I unplugged the cam sensor and the fuel pump shut off. Your cam sensor is on top of that shaft where the distributor use to be. Something to try that doesn't cost you anything.
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Unread 03-13-2014, 09:58 PM   #22
who_datjeep
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Thanks a ton CCKen. I will do that and get back with the results. Lol yes, I am making progress.

Hey MMPerformance, that's a good idea, how do I test the camshaft position sensor? I'm going to check the PDC first then try that.

Also going to fix the yellow wire.

Thanks a ton to everyone, really making my life easier.

Kevin
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Unread 03-14-2014, 11:45 AM   #23
MMPerformance
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Have the key on so you can hear the fuel pump running and unplug the cam sensor and see if the pump goes quite. The cam and crank are on the share the same 5volt supply and sensor ground either one can drive the pcm nuts if they short or bleed voltage over. Also the MAP and TPS are on the same 5 volt line and the MAP, TPS, ECT, O2 sensors, VSS and others share the same sensor ground line. To test the cam sensor would require a graphing mulitmeter or a scope and a scan tool, not a code reader. Do you have access to any of those tools?




CAMSHAFT POSITION SENSOR - GRAY 2 WAY CAV CIRCUIT FUNCTION
1 K44 18TN/YL CAMSHAFT POSITION SENSOR SIGNAL
2 K167 20BR/YL SENSOR GROUND
3 K7 18OR 5V SUPPLY
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Unread 03-14-2014, 12:03 PM   #24
who_datjeep
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I'll try unplugging it and see if that makes any difference. I don't have access to any of those tools.
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Unread 03-15-2014, 01:39 PM   #25
who_datjeep
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So I tried disconnecting the camshaft position sensor, and that didn't make any difference on the fuel pump. Maybe it's the fuel pump that's the problem?

Where do I look for corrosion under the PDC? See picture.

Thanks,
Kevin
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Unread 03-15-2014, 02:32 PM   #26
who_datjeep
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It seems with all these electrical problems I should start testing with an ohmmeter. Maybe the relays are not getting enough power and I can check the terminals in the PDC. Does anybody know which terminals to test? Also could I test the fuel pump connector? Or should I test the fuel pressure first?

Thanks,
Kevin
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Unread 03-15-2014, 04:48 PM   #27
CCKen
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Quote:
Originally Posted by who_datjeep View Post
So I tried disconnecting the camshaft position sensor, and that didn't make any difference on the fuel pump. Maybe it's the fuel pump that's the problem?

Where do I look for corrosion under the PDC? See picture.

Thanks,
Kevin
See post #20. You have to disassemble the PDC to look for corrosion INSIDE of the PDC.
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Unread 03-15-2014, 05:36 PM   #28
who_datjeep
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Originally Posted by CCKen View Post
See post #20. You have to disassemble the PDC to look for corrosion INSIDE of the PDC.
How do I disassemble it more?

Thanks,
Kevin

This is where I am:
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Unread 03-16-2014, 08:38 AM   #29
CCKen
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How do I disassemble it more?

Thanks,
Kevin

This is where I am:
That should be adequate to see what you need to see. Look for evidence of water intrusion...corrosion... bridging the wire pin cavity connectors, and wire chafing.

Edit: Clean everything off real good before reassembly using CRC QD Electronic Cleaner.
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Unread 03-17-2014, 08:55 AM   #30
MMPerformance
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Quote:
Originally Posted by who_datjeep View Post
So I tried disconnecting the camshaft position sensor, and that didn't make any difference on the fuel pump. Maybe it's the fuel pump that's the problem?

Where do I look for corrosion under the PDC? See picture.

Thanks,
Kevin
It won't be the fuel pump that is the problem. The relay for the fuel pump is controlled by the pcm, unplug the relay, if it's still on then you have wires making contact somewhere powering it up. If it shuts off, the pcm is keeping in turned on for some reason, could be the other sensors on the same line.
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cherokee , crank , fuel pump , no start , spark

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