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Hard hot start causes

Try unplugging the abs, if that doesnt help try the airbag, and so on. Also make sure all the fuses are good so all the modules can come online. If one doesnt power up, it can hold the data bus to ground, and kill data coms. Its just wierd getting a u1000 on a pre bcm truck since u1000 is basically a bcm code.
 
Weird, again, has low voltage written all over it. What does the ECM say it's voltage is? Open or shorted diodes in alternator can mess up ecm's due to AC ripple.
 
MrMarty51 said:
Try Your multimeter at the batt terminal on the back of the alternator, set it on A/C voltage. If it read voltage then the diodes is bad in the alternator.
Click to expand...
You will always get some ac voltage at the back of the alternator. Ideally you want to see less than 1 volt at the alternator, and less than .3 volts ac at the battery. I remember going through electrical class at Dodge, and the instructor had us testing brand new cars that had .5-.8 volts ac at the alternator stud.
 
So I think I'll have some time to look at this for a couple of days. Started out by going to a wrecking yard and picking up a Passlock module. So in my reading and searching about this module it handles the EVO, the Passlock, and the Vats. There's an outfit called pro-rebuild that fixes these. Most don't require a core but if you have one that ends in number 65 it's semi rare and appears to be what at least the heavier trucks use. The one I picked up was out of a 2000 CC 1ton so I'm assuming it's the same as mine. After talking to the parts guy at the dealer he seemed to think the different numbers on them were related to 1/2,3/4, or 1 ton. But there's 6 different numbers.
As far as getting to it it's not super easy. It's located underneath either the cubby or CD player kinda on the left side. If you pull the cubby out you can see the tabs that hold it in but that's not the access to it. You have a to pull apart the bottom of the dash and remove the ashtray. At least on gasser's you can also reach up on the left side of it and touch it that way too. The wires don't have much slack in them.
I'm thinking about replacing mine to see if it maybe the communication code I have.IMG_20190409_141900.jpg
 
So changed out the module. I made a modification to the dash and now it's relatively easy to get to.IMG_20190410_121033.jpgIMG_20190410_121019.jpg
Didn't change the U1000 code though still there. My factory service manual doesn't even list that code but the service manual does mention the class 2 serial communication though.
On my way to Anchorage to look at a car to buy so that's probably it for today.
 
This is out of my 98FSM. At least I know U codes do exist for gmt400. Didn't mention my U1000 though. Paveltoz found a U1016 in his 99 manualIMG_20190411_144710.jpg
 

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There are several U codes dealing with loss of coms with a specific module, u1000 is for the bcm which you do not have.
 
So when I went to start it it wouldn't. I had to do the learn for the Passlock. What I did find interesting was that it learned differently than the last time I did it. The first time it did it like I had changed the key part. This time it did it like I'd changed the Passlock. Irregardless of what you want to call the module changing the PCM made the code go away. I also put a new PMD on whilst I was doing things as it stalled on me yesterday.
Took it out for a drive to get it warmed up good and then let it sit for 1/2 hour. While it didn't just pop right off it did start quite a bit easier. I'm hoping that the delayed start is just our winter fuel still. Time will tell.
 
So I was talking to Quadstar yesterday about a tune and he said the u1000 code is what you get when you disable Passlock in the PCM. He also said the security light should not light. So between the security light on mine being active and a boost code that would instantly reset he figured the PCM really did have issues. I'm going to get a tune from him , I never was impressed with the Heath tune. Didn't seem to do anything more than the stock tune. But I understand that the later oem tunes were a hotter tune.
 
A couple weeks before they switch to winter fuel. Get 10 gallons or so of #2. Add stabilizer and make sure the container(s) 100% full. The container should be steel not plastic and perfect sealing lid.

If the problem begins again next winter test with the known good fuel. You might need to use artificial heat to keep it from jelling, and no additives to do that with so the fuel stays “true”.

You don’t have any of the known same winter fuel around in a piece of equipment like your forklift do you? If so, steal 5 gallons from that and run the 2 fuel
Lines from that in bed in a jerry can to engine and return to see if thaat winter blend is the problem.
 
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