I have an 01 ranger xlt, 3.0 5 speed manual. The trucks lifted on super swampers, straight swapped front with less than 90k. The issue I’m having randomly is the truck completely dies at random when driving. No sputter or anything, just suddenly shuts off. My air fuel gauge even shuts off as well. I’ve replaced the crank sensor, coil pack, wires, plugs, new fuel pump, new dove sensor, and have a new tps to put in. The truck throughs random codes when it dies such as p0720, p0102, p0451 and p1633. I know the speedometer stopped working so the out put speed sensor is accurate, however at times when I try to read codes it just gives an error. When I attempt to restart the truck it will usually crank and crank but won’t fire up, other times it does absolutely nothing and after a while it starts just fine and runs fun. Inertia switch isn’t tripping, my overall thought now is the ecm is going thus causing the shut off, odd power issues, the random/error codes. Has anyone else ever had this issue? Mahalo in advance for the advice.

This is the truck.

 

Yes, I would look for a new/used PCM, engine computer, it reads like that would be the most obvious issue with the random codes and the "error connecting" with OBD reader

Although P1633 Keep Alive power too low, could indicate PCM is losing voltage completely which causes the sudden stall
You don't mention the dash warning lights not working just fuel gauge
Whats your battery condition and alternator condition?

2001 Ranger has PATS(passive anti-theft system) in the PCM so you will need to reprogram your TWO PATS keys once the PCM is installed or vehicle will not start

You can do that yourself with Forscan software, read up on it, you can use it free for 30 days I think, there are detailed instruction on how to do it at Forscan forum
Or a mobile Locksmith can come to you and do the key reprogramming
MUST HAVE at least TWO PATS working PATS keys, no clones, to add or it won't work

You can buy new PCMs that come with 2 keys already added to the PCM, but you will need to take those to a locksmith so he can cut them to match current key/lock

 

Battery is brand new, alternator looks fine as well. Did the alternator test a while back by disconnecting the battery and the truck stayed on. Battery light comes on when it dies, check gauge comes on and check engine stays on. What pointed me to the pcm was the random/error codes and it wanting to start and not wanting to turn over at all like no power was going anywhere to crank. Thanks for the heads up on the keys. Online I found a set, it said I can turn the new key in the ignition to on for 3 seconds then remove and repeat with the secondary.

 

Don't do that test again, you WILL fry the voltage regulator or another electronic part, with the voltage spike that comes when you reconnect the battery cable

That test was from 40 years ago when we use mechanical(relays) voltage regulators, so if a vehicle is 1985 and newer just don't do it
Use a volt meter they are way cheaper than a new part

And yes you CAN do it and get away with it, it won't burn out something every time, its just when it does you will be mad, lol

 

Also my volt meter gauge I installed doesn’t read anything out of the norm at all.

 

Ah, touché, didn’t think about the spike. But yeah so that’s where I’m at is it has to be the pcm. Unless someone knows something I don’t by chance.

 

Well the adding a key thing is correct but NOT complete

IF.......the new PCM comes with TWO "working keys"(already programmed into its Memory), then they just need to be cut to match your lock
Then with those two working keys you can add your current keys to new PCMs PATS memory, so have a 3rd and 4th key if you have two now

You can't just insert any PATS keys and turn ignition on and off to add them, it wouldn't be much of an "anti-theft system" if that was the case