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Unread 09-01-2013, 03:30 PM   #31
JBrady5555
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1997 ZJ 
 
Join Date: Jun 2013
Location: Panama City, Fl
Posts: 163
Just doubled checked all the fuses in the box by the battery. They were all good. Are there anymore fuses anywhere on the zj that I'm missing.

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Unread 09-01-2013, 03:41 PM   #32
Oldfrog
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1997 ZJ 
 
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A visual check isnt always accurate. So let's get that ASD fuse question answered before we move on. PULL the ASD fuse and, inspect and clean the connection, then put an ohmmeter across the fuse to check it. Sorry, but it needs to be 100% eliminated from being the problem.

Next, clean and tighten all your grounding points. Blow oil dipstick, below coil and fender well, by the battery.

My guess is that something fried while you were arcing power at the battery posts. That's the fastest way to ruin a PCM, but a fuse will usually pop first.
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Unread 09-01-2013, 03:44 PM   #33
JBrady5555
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Quote:
Originally Posted by ZeeJay1997 View Post
It could have blown any number of fuses or fried the PCM... or anything else.

Best place to start would be at pin 22 on the black PCM connector. That is where the PCM picks up its power.
By pcm you mean that black box by the battery right? Also I'm not sure where this connector is at that your talking about, or how to find pin 22 for that matter. I've got one of those testers with the sharp point to check stuff like that, I'm just not sure what to check.
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Unread 09-01-2013, 03:48 PM   #34
Oldfrog
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1997 ZJ 
 
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The PCM is the engine computer on the firewall behind the coolant bottle. Dont go sticking a pointed tester probe into the insulation of it's wires unless you really want trouble later. Get a T-pin back probe to insert into the connector pin and attach an alligator clip to it...then to your voltmeter.
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Cajun Recipes and Fishing tips

Words of wisdom, Posted by Zeejay:
"..it's not air, it is the opposite of air... suckage so to speak."

Stalling? Work through Zeejay's list
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Unread 09-01-2013, 03:49 PM   #35
ZeeJay1997
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The fact that the CEL is not coming on for 3 seconds when you turn the key on is the most telling clue you have here. (given that you know it worked before). No other fuses will cause this type problem.

Now you need to check power to PCM. if it's good, disconnect the crank sensor, then o2 sensors. After you unplug each sensor, check to see if the CEL lamp check works when you turn the key on.

What you are trying to accomplish is to be sure nothing external to the PCM has it shut down.

But all of this is for naught unless you verify that power is at pin 22.
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Unread 09-01-2013, 03:50 PM   #36
JBrady5555
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1997 ZJ 
 
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Quote:
Originally Posted by Oldfrog View Post
A visual check isnt always accurate. So let's get that ASD fuse question answered before we move on. PULL the ASD fuse and, inspect and clean the connection, then put an ohmmeter across the fuse to check it. Sorry, but it needs to be 100% eliminated from being the problem.

Next, clean and tighten all your grounding points. Blow oil dipstick, below coil and fender well, by the battery.

My guess is that something fried while you were arcing power at the battery posts. That's the fastest way to ruin a PCM, but a fuse will usually pop first.
In a few minutes I'll borrow my grandfather and his ohm meter. I don't know how to use one. How do I check the 3 prong asd relay with a ohm meter?
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Unread 09-01-2013, 03:58 PM   #37
ZeeJay1997
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Look behind the coolant reservoir. Box with 3 connectors. You can take the black one off by releasing two locking tabs. You can see one but the other is on bottom where you cant see it. Pinch those together and rock the whole connector and pull out

Then look at the connector and find pin 22 as shown below. Connect the black lead to the ngative battery terminal. Put it on DC volts scale greater than and closest to 12v. Then go to pin 22 with the red lead.

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Unread 09-01-2013, 04:16 PM   #38
JBrady5555
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1997 ZJ 
 
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Quote:
Originally Posted by ZeeJay1997 View Post
Look behind the coolant reservoir. Box with 3 connectors. You can take the black one off by releasing two locking tabs. You can see one but the other is on bottom where you cant see it. Pinch those together and rock the whole connector and pull out

Then look at the connector and find pin 22 as shown below. Connect the black lead to the ngative battery terminal. Put it on DC volts scale closest to 12v. Then go to pin 22 with the red lead.

Cool found it. Grand is on the way with ohm tester. I want to test the 3 prong relays too. How do I do that? Thanks to all you guys for the help
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Unread 09-01-2013, 04:21 PM   #39
ZeeJay1997
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Quote:
Originally Posted by JBrady5555 View Post
How do I check the 3 prong asd relay with a ohm meter?
Unless the PCM is working, the ASD relay is of no consequence at this moment.
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Unread 09-01-2013, 04:24 PM   #40
JBrady5555
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Ok pin 22 is showing 12v. What to check next
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Unread 09-01-2013, 04:39 PM   #41
JBrady5555
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I also test a17 pin. The 5v supply, I got zero volts with key off, .9 with key on.
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Unread 09-01-2013, 04:56 PM   #42
ZeeJay1997
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The 5v is an output of the PCM so you wont read anything with it disconnected. Reconnect the black connector to the PCM.

Then go over to the tps on the throttle body. its the sensor closest to the firewall. disconnect the connector and turn ignition switch on. check for 5v on the two outside sockets on the connector. this is the output from pin 17.
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Unread 09-01-2013, 05:09 PM   #43
JBrady5555
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Quote:
Originally Posted by ZeeJay1997 View Post
The 5v is an output of the PCM so you wont read anything with it disconnected. Reconnect the black connector to the PCM.

Then go over to the tps on the throttle body. its the sensor closest to the firewall. disconnect the connector and turn ignition switch on. check for 5v on the two outside sockets on the connector. this is the output from pin 17.

I got .16 and .7 on the outer pins. 1.46 in the middle pin.
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Unread 09-01-2013, 05:12 PM   #44
Oldfrog
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Stay with Zeejay on this...but I never mentioned testing the ASD RELAY...only the fuse.
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Cajun Recipes and Fishing tips

Words of wisdom, Posted by Zeejay:
"..it's not air, it is the opposite of air... suckage so to speak."

Stalling? Work through Zeejay's list
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Unread 09-01-2013, 05:14 PM   #45
JBrady5555
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Oh ok thanks
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