Solved Everything you wanted to know about PATS.

[CoalHeat]

My '98 XLT won't start. About a month ago it quit, I went into the system with my scan tool and everything pointed to the PATS transceiver. I bought a new transceiver from Ford, installed it and the truck started and was running fine until this past week. Began to have intermittent difficulty starting, until finally it quit completely (in my driveway at least). I have DTC P1260, engine disabled by PATS. I then went and looked at the PATS module, it is not showing any trouble codes and is showing that the engine is "enabled". So the PATS module is saying the engine is enabled and the PCM has the engine disabled due to a PATS issue. What do I do now????

 

[slide112]

Its probably not related to pats..

My truck wont start,ive checked EVERYTHING so as a last resort i was trying to figure out how pats worked

Doesnt really matter now,i had my tuner tune PATS out,i didnt know that could be done

I did not know you could do this either. Please tell me how.

 

[imp]

I did not know you could do this either. Please tell me how.

BY ALL MEANS, TELL US HOW! imp

 

[BobWiersema]

My '98 XLT won't start. About a month ago it quit, I went into the system with my scan tool and everything pointed to the PATS transceiver. I bought a new transceiver from Ford, installed it and the truck started and was running fine until this past week. Began to have intermittent difficulty starting, until finally it quit completely (in my driveway at least). I have DTC P1260, engine disabled by PATS. I then went and looked at the PATS module, it is not showing any trouble codes and is showing that the engine is "enabled". So the PATS module is saying the engine is enabled and the PCM has the engine disabled due to a PATS issue. What do I do now????

When you replaced the transceiver did you replace the short wiring connection that goes from the transceiver down to a 4 pin connector just off the steering column? If not, that's where the problem is. It gets tugged apart from tilting the wheel. The wires pull out of the smash on's inside the molex connector. Cut the connector out and bypass it. Write down wire colors first because they don't match up on both sides.

 

[CoalHeat]

Actually the new transceiver came with the short harness as part of the assembly, the old unit had a connector on it to disconnect the short harness, the new unit doesn't have the connector. One of the first items I checked was that connector where the short harness connects to the body wiring harness. Disconnected and reconnected, it's tight. If that was at fault it should throw a code B1681 which is PATS transceiver fault, which I had before replacing the transceiver. That is what's got me stumped.

 

[BobWiersema]

Actually the new transceiver came with the short harness as part of the assembly, the old unit had a connector on it to disconnect the short harness, the new unit doesn't have the connector. One of the first items I checked was that connector where the short harness connects to the body wiring harness. Disconnected and reconnected, it's tight. If that was at fault it should throw a code B1681 which is PATS transceiver fault, which I had before replacing the transceiver. That is what's got me stumped.

When you turn the ignition on, without turning to start. Is the Theft light flashing? Do you have a picture of that four pin connector you can post? I know it may look fine. Mine did. That's because it's crimped in two spots on those Molex pins. If it pulls out just a bit, it loses contact but is still held in place by the top crimp and shielded by the wire insulation. (Warning! don't put a volt meter on it)
Just what I've been told. FYI, I have repaired this exact same problem on five 98 Explorers (including my own after replacing the transponder) by bypassing that connection.

 

[CoalHeat]

The Theft light flashes as it's supposed to when the ignition is shut off. When the key is turned to "on" the theft light comes on steady for a few seconds then goes out (system "proves out").
I don't have a photo hosting service, I believe that is needed to post photos here. Tomorrow I will examine the connector again. Thanks.

 

[jd4242]

I did not know you could do this either. Please tell me how.

BY ALL MEANS, TELL US HOW! imp

The tuner turns its off in the tune..the truck has to have a custom tune though and cant be done by you via the handheld. .hes also turned my downstream O2s off..

 

[BobWiersema]

The Theft light flashes as it's supposed to when the ignition is shut off. When the key is turned to "on" the theft light comes on steady for a few seconds then goes out (system "proves out").
I don't have a photo hosting service, I believe that is needed to post photos here. Tomorrow I will examine the connector again. Thanks.

According to the service guide. If I remember correctly, once the light goes out, it has read the key correctly. Sounds like it's not passing that information to the ECU. Is that the only code? Are you able to read codes from the BCM? (Body control module) If your not absolutely stranded, I can look at the service guide and see what I can find. Unfortunately, that lives on a computer at home and I won't be home till Monday. Sorry, if I think of anything I'll let you know. I do kind of remember a flow chart in the service guide that could help with this, just can't access it right now.

 

[BobWiersema]

This could be a shot in the dark but. Have you cycled power? Just spit-balling.

 

[CoalHeat]

Yes I have. I'm not pulling any other codes except B1352 Ignition key in circuit fault, that is because the little switch that fits on the lock cylinder housing under the PATS transponder is broken, so when the key is inserted it doesn't make contact. Sadly the annoying key chime doesn't work either. But this has been this way for a while and the truck was starting and running with this fault. If I go into Live Data on my scan tool I can see the ignition data change from off to on as I turn the cylinder to it's respective positions.
I'm not stranded, driving my F-250, any assistance is much appreciated!

 

[BobWiersema]

Yes I have. I'm not pulling any other codes except B1352 Ignition key in circuit fault, that is because the little switch that fits on the lock cylinder housing under the PATS transponder is broken, so when the key is inserted it doesn't make contact. Sadly the annoying key chime doesn't work either. But this has been this way for a while and the truck was starting and running with this fault. If I go into Live Data on my scan tool I can see the ignition data change from off to on as I turn the cylinder to it's respective positions.
I'm not stranded, driving my F-250, any assistance is much appreciated!

I'm curious to know what that switch is wired to. Could be doing more than just the chime. I'll check that on the schematic. I should be back home late afternoon Monday.

 

[BobWiersema]

One noteworthy thing. When I bought the Explorer new in 98, I did try to unplug the key chime box because I was doing service work in the winter and the door was often open while on a job site. It would not start without it. Could mean something.

 

[CoalHeat]

That little switch also tells the system whether the key is in or out of the ignition. On my scan tool I could go into live data and see key in/key out as I inserted and removed the key. The flimsy little switch was damaged and broke when I changed the transceiver a month ago. I was afraid it would prevent the vehicle from running, but it was starting right up until last week.
The glitch still remains however: The PATS module says the engine is "enabled" and the PCM has the engine disabled due to the PATS system. I'm thinking the PATS module went whacky.

 

[BobWiersema]

I think you can replace it with a junk yard one but you will need at least two key that belong to that system.

 

[BobWiersema]

Some good PATS info I found. Handy if you replace the module. Looks like you can use the old keys.
I wonder if you need to initialize it.

PCM REPLACEMENT (scan tool required) After installing the replacement PCM, an Antitheft initialization must be performed using a scan tool with PATS capability.

http://www.counterpersontraining.co...ral/Sites/Global/File/standardfordrelearn.pdf

 

[CoalHeat]

Thanks for that info Bob, I appreciate it! I'm gonna take a shot at replacing the PATS module and see what happens. I hate throwing parts at it without an exact diagnosis, but since the module is telling me the engine is "enabled" and the PCM is setting the code for "engine disabled by PATS module" something is amiss.

 

[CoalHeat]

Well I was just reading that info, mine is type "B" and my scan tool doesn't have the capability to do the required steps so I'm back to square one now.
The last thing I want to do is have it towed to the dealer so they can charge me a fortune so I can have a truck that actually starts!
It looks like it's saying to cycle the 2 keys and then if the vehicle doesn't start then you have to do a KAM reset with the scan tool. So it might work.....

 

[BobWiersema]

I think you still have to do a antitheft initialization on the PCM if you replace the module. At least that's how I read it

 

[CoalHeat]

Yes, I believe you are correct.