Hey folks. I'm hoping to find some help on the forum about my fiancè's truck regarding the PATS "going bad" or possibly being damaged by a remote start install (though it was five years ago).

First off, the truck is a 1999 B4000, 2WD, +/-200k mi with an aftermarket remote start (installed in 2005 - no problems until now).

Several weeks ago the truck would occasionally crank for 15 sec before firing up. Normally it fires after half a second or so. Last Saturday it quit entirely. I, foolishly diagnosing a fuel pump failure as it had happened almost exactly the same way to a family member's vehicle, replaced that without actually testing the pump. When that didn't work, I paid a local shop to run a scan on the computer which came back as number of no key starts exceeded and said the PATS was not allowing the computer to fire the truck.

Took it to a mazda dealership. They have now had it close to a week and can not figure out what is wrong with it. The guy who installed the remote start swears it has nothing to do with his system (as they all do), and walked the dealer tech through disabling it. The truck still won't start.

The dealership says they want to replace the PATS module though there is NO guarantee that will work. $175 for the module ($600 total). Is it possible for the PATS to "go bad" and require replacement? I'm a fairly competent mechanic, is there a place to buy the PATS that I could replace it myself. Has anyone experienced a similar problem with a remote start installed (like the PATS bypass going bad - only $30). Could it be related to a crankshaft position sensor or simply an ignition switch?

I would appreciate any help you all can provide. I've tried the search and there are no results for "PATS" or "Passive Anti Theft System" in the truck forums at all.

Aaron

 

I have a 1999 B4000 with the same problem.I think I have resolved the issue.
Sometimes the truck will not start but it cranks.The PAS shuts off the spark.After may time of this happening and many mechanic's I found that if you leave the key in the ignition, Remove both battery terminals and wait 10-15 minutes put the battery terminals back on but do not remove the ignition key the truck will start. I keep the key in the ignition with electrical tape over it so I do not remove it.I had another key made at walmart to unlock the doors So far 3 months have gone by and no problems

 

Man, this is an old thread that I'd surely forgotten. I really was going anywhere I could trying to find an answer. Now that someone has brought it back, I will answer my own question for future users/searches; though these little trucks are becoming more rare every day.

I mucked around with dealerships for another six months after this post, no one could solve the problem, they ended up replacing the main computer, reprogrammed keys etc. I think I paid a total of around $700 on various parts. Fortunately (I guess) after all the work with no solution, the two dealerships did not bill me for the 45 more or less man-hours working on the problem. We then let the truck sit over the winter as we situated in our house (plenty of other vehicles available).

Mid-year 2011, I looked into the problem myself, having gone nowhere with dealers. I found an obscure reference in some long post on a different manufacturer about a crankshaft position sensor causing a no start condition with no trouble codes or errors even being detected by a dealership "level" computer. Figured what the hey, its a $25 sensor and takes less than 5 min. to replace.

Lo and behold, that was it; the crankshaft position sensor. Immediately started after almost a year of not starting. Has never faltered since. But now the poor truck sits with minimal attention waiting for me to get into the transmission and figure out which checkball is missing preventing it from properly engaging in reverse. Then repair to the wheel wells on the bed where the arches are rusting, then the cam position sensor to get it firing on all 6 cyl consistently. Not much money, just needs time which becomes quite the valuable commodity these days.

 

I'm not kidding about the level of research before I found that seemingly simple answer. I have a bookmark folder of literally 20 - 30 book marks on descriptions of the problem. Hope this helps someone in the future. Also, I did not post the correct mileage on the thing, it only has 143k which I would consider very low for electronic sensor failure.