I'm stuck about 300 miles from home, I don't have AE on hand just SGII and my SG isn't reading any codes. My mpg is about 2-3 according to my SG and it won't read the MPH on my SG, no cruise control and the speedo is moving extremely erratically. It all goes away when I kill the truck and restart is but after a few miles it starts back up. This started when I was getting ready to go back home this afternoon and checked all my fluids, noticed that the trans fluid was a little low so I put about 1qt in it and got on the interstate and noticed I didn't have CC. From what I'm gathering on similar threads it could be the VSS, maybe the PCM?
Help! Od blinking, no cruise control, speedo moving erratic
- Thread starter Jeromy
- Start date
Arisley
Moderator
Sounds and acts like VSS.
Should be fine making it home. Sucks to drive that far with no cruise. Use GPS for speedo if you have one. Keep an eye on the trans temp.
Should be fine making it home. Sucks to drive that far with no cruise. Use GPS for speedo if you have one. Keep an eye on the trans temp.
The problem was a combination of the VSS and PCM being wet, I found someone with AE and got a vss code so I went to O'reillys and fortunately they had a Motorcraft in stock. I pulled the PCM and there was some water in between the pins so dried it off with a hair dryer, then I cleaned it up with electronic cleaner and popped it back in. So far so good, no problems whatsoever in about 50 miles.
farmall99
Member
Check behind the drivers side headlight. There's a ground bolted to the core support that likes to work its way loose occasionally. Gave me fits when the speedo was acting up on my 03.
I'm pretty sure it had something to do with the PCM getting wet, for some reason when I drive through heavy rain it happens. Something similar happened about 6 months ago but I pulled into Walmart to pick up some stuff and everything was fine but when I went back to the truck it wouldn't start and just cranked over, eventually after about an hour it started back up and when I got home the IDM was wet and so was the pin connector on the PCM. I didn't have any more problems once they dried until the other day when this happened. I'm going to pick up a spare PCM from the local junkyard tomorrow, also going to see where water is getting in from and reseal it.
lincolnlocker
Well-known member
hmmmm... dont remember one on my core support when i pulled my motor last summer... is it on all 99-03 superdutys?
live life full throttle
No there are 3. The one goes from bottom of the pass side block to frame. Similar on drivers side. Then one from motor to firewall on pass side rear. At least thats all I recall.
lincolnlocker
Well-known member
powerstroke95
Member
If the grounds check out, try unplugging your alternator. Mine was going bad and causing similar issues. Replaced the alternator and everythings been fine ever since.
Lethalthreat7.3
New member
Check the vss wiring back where it crosses over from the frame. I've seen a ton of trucks, vans and old bronco's have an issue from rubbing. It shows itself usually when things get wet.
Water in the pcm however is obviously an issue. If it works fine when dry then seal the leak and don't spend $ on a new one.
Water in the pcm however is obviously an issue. If it works fine when dry then seal the leak and don't spend $ on a new one.
lincolnlocker
Well-known member
farmall99
Member
This is the ground I'm talking about. It's directly in front of the battery box on the drivers side. That bolt was loose and when I tightened it up my speedo issues went away.
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I'll check that out in the next couple of days when I swap and reseal my new PCM, I picked one up for $35 at a junkyard because I couldn't pass up the price.
Thanks! I don't think that's the cause of my issues but I'll check it out.
Alternator is only about 6 months old, so are the batteries.
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