Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
BCM
User Panel

Posted: 12/27/2014 10:44:58 AM EDT
I was trying to diagnose my cranking but no start a couple weekends ago and it has since turned into no crank no start.

The car was running when it was parked and has sat for about 2-3 weeks. When I tried to start it a couple weekends ago it wouldn't stsrt. Narrowed it down to the fuel pump not priming up so I checked all fuses and swapped the relay for a known good one. Did not fix the issue so I unhooked the battery and disconnected the fuel pump connector (I have the returnless system). I was getting 6.8v from the purple/yellow to the black wires with it unplugged.

I thought there was supposed to be 12V to the fuel pump so I thought there might be another issue upstream. Tried jumping 12v directly to the fuel pump with it disconnected but it still didn't come on. I hooked he connector back up but now it won't event crank over.

The PATS light blinks with the key off, accy, but turn it to on and the light goes away. I have full dash lights (check engine light never turns off when the key is on) and half go off when I turn it to start. Funny thing is even when I remove the key the PATS light never blinks unless I unhook the battery and reconnect it.


Is this an issue with a ground? PATS malfunctioning? Neutral safety switch?

The light does blink normally until I turn the key. Funny thing is when I turn the key the PATS light goes away completely (no fast blink or anything).
Link Posted: 12/27/2014 10:46:08 AM EDT
[#1]
I checked the connections today and the main harness, pcm and pcm ground checked out fine. Something interesting is that the battery had been drained completely dead. When I put it on the charger it still has no cranking. I did verify that the starter works by jumping power directly too that. Any ideas?

Is it possible that the device that reads the key is bad? I've heard these can go out without warning. Any way to test them or bypass?

Is it also possible that I erased the key/put it into programming mode by turning it to various positions during the troubleshooting process?

I only have one key but do have a complete parts car which is a 1998. From what I've read I can't just have the keys recut from that car because I dont have 2 originals for my 99
Link Posted: 12/27/2014 3:11:53 PM EDT
[#2]
How old is the battery? I'm going to throw the simple stuff in here first and say that perhaps the initial problem may have been a shot fuel pump, and the current problem may be that and a battery that may just be too old to be sitting around in a WI winter for a couple of weeks without use
Link Posted: 12/27/2014 6:40:25 PM EDT
[#3]

Discussion ForumsJump to Quoted PostQuote History
Quoted:


How old is the battery? I'm going to throw the simple stuff in here first and say that perhaps the initial problem may have been a shot fuel pump, and the current problem may be that and a battery that may just be too old to be sitting around in a WI winter for a couple of weeks without use
View Quote


I would start there also. Not just recharge it but get it load tested.



From there move onto the schematic. Find the starter relay and probe the wire that is supposed to get the ground signal or low amp +12V to activate it when you turn the key . If no signal present there then you work your way back the the PCM some more.



 
Link Posted: 12/28/2014 2:15:04 PM EDT
[#4]
The battery is fine and I've also tried jumping it.  Unfortunately the schematic In my manual doesn't match what the car actually has on it . Heck even the fuse box layout is different!  Stupid schematics for different model years.
Link Posted: 12/28/2014 10:30:21 PM EDT
[#5]

Discussion ForumsJump to Quoted PostQuote History
Quoted:


The battery is fine and I've also tried jumping it.  Unfortunately the schematic In my manual doesn't match what the car actually has on it . Heck even the fuse box layout is different!  Stupid schematics for different model years.
View Quote
OK. I dont know how many times Ive given people advice on getting their battery load tested and they tell me its fine. Then later on tellme I was right. I'lltrust you on it.



Do this..............



Find the starter relay. Verify this. One pin should be 12V direct to battery, one pin should be chassis ground. One pin should go directly to the starter solenoid. The last pin should be the signal form the PCM. Find a really thin wire ( like telephone wire ) and wrap it around the pin and insert it back into the socket it goes to.



Now use your DMM to see what you get when you go to crank the car.



 
Link Posted: 12/29/2014 5:21:48 PM EDT
[#6]
There should be an emergency fuel cut-off switch under the dash, somewhere around the glove box.
It's supposed to be an inertial (impact) switch that trips in the event of a wreck.
It should have a red button that you can push in to reset.  
If you're in Wisconsin, y'all have had some pretty damn cold weather... I don't know if extreme low temps could cause trouble with that cut-off switch, but it costs nothing to check it

Edit:  I misread your title, I thought it would crank but not fire.
In which case, my suggestion above isn't likely to help.

Does it have an alarm and/or anti-theft device?
Link Posted: 1/18/2015 10:16:01 PM EDT
[#7]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
OK. I dont know how many times Ive given people advice on getting their battery load tested and they tell me its fine. Then later on tellme I was right. I'lltrust you on it.

Do this..............

Find the starter relay. Verify this. One pin should be 12V direct to battery, one pin should be chassis ground. One pin should go directly to the starter solenoid. The last pin should be the signal form the PCM. Find a really thin wire ( like telephone wire ) and wrap it around the pin and insert it back into the socket it goes to.

Now use your DMM to see what you get when you go to crank the car.
 
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
The battery is fine and I've also tried jumping it.  Unfortunately the schematic In my manual doesn't match what the car actually has on it . Heck even the fuse box layout is different!  Stupid schematics for different model years.
OK. I dont know how many times Ive given people advice on getting their battery load tested and they tell me its fine. Then later on tellme I was right. I'lltrust you on it.

Do this..............

Find the starter relay. Verify this. One pin should be 12V direct to battery, one pin should be chassis ground. One pin should go directly to the starter solenoid. The last pin should be the signal form the PCM. Find a really thin wire ( like telephone wire ) and wrap it around the pin and insert it back into the socket it goes to.

Now use your DMM to see what you get when you go to crank the car.
 


I checked the wiring diagram and the PCM is merely to finish the path to ground.  However read the testing that I did today:

Because I have read of so many people with similar issues I am going to try to detail everything I have done quite thoroughly.  For those that might be trying to track down a similar issue I discovered that Auto Zone has wiring diagrams listed out by year - this has proved very invaluable to my testing process.

Because it will not crank over I decided to focus on the starting system:

- Power to the ignition cylinder/switch- Checks out ok
- Power to the green starter relay (relay 7) in the engine compartment - check
- relay is not switching
- relay switches when manually grounded / Car cranks but does not start (even with starter fluid)
       - issue is downstream of this point
             - Neutral/Park gear sensor
             - Wiring to PCM from previous sensor
             - PCM
- Manually ground PCM side of Neutral/Park gear sensor - Car cranks but does not start (even with starter fluid)
**This leads me to believe the PCM is faulty or the PATS system is malfunctioning

Did some swapping/comparing to my rusted out but running '98 donor car
- Swapped ignition antenna ring - Checks out ok
- Swapped the ignition switch (electrical portion) - Checks out ok

I also hooked my computer with my Ford ScanTool program up to the car and it will not communicate with it at all.  The program communicates with the '98 donor car without any issues.  It also gave me hope if I can get them to communicate because there is a key programming option in the ScanTool software.
**Again this leads me to PCM being faulty and causing it not to communicate**

I was going to try swapping the PCM from the two cars but my donor is a '98 with a return style system and the car I am working on is a '99 with returnless.  Can someone tell me if it will at least make it run?  I know the timing curves/transmission stuff might be a little different but if I can prove the PCM is bad I would feel alot better spending the $$$ on the correct one.
- Donor '98 is a 98BB-12A650-BZA (Code AZB0)
- Current '99 is a XS2A-12A650-GD (Code LXP3)

Another thing I noticed is that something is flowing/using electricity all the time (PCM?) as the ground post will spark slightly when I hook it up to the battery (all doors closed, lights and ignition off).  After watching some youtube videos this may be normal?
Also the fuel pump has no power (purple+orange) to it with the key off after hooking up the battery but if you cycle the key on, then off again the fuel pump still has power.

In short I'm thinking that either the key is bad and therefore keeping the ScanTool program from talking to the PCM or the PCM itself is bad.  Any more advice is appreciated.
Close Join Our Mail List to Stay Up To Date! Win a FREE Membership!

Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!

You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.


By signing up you agree to our User Agreement. *Must have a registered ARFCOM account to win.
Top Top