abc4yew

Well my truck has been working awesome for 15k since I put an '04 HO in my 0'03 SO truck.....until today.... sure I've had a few unexplained codes....but while 300miles away from home my auto trannied truck decided to go auto gear and throttle control.

This seems to be an ECM problem. I did change from Smarty sw7 to sw5 and thought that this may have finally triggered the ECM to finally realize that this 04 engine is hooked to an 03 truck with separate ECM and PCM.

Here is the list of codes

p0700 Transmission controller
p0720 Low output speed sensor rpm greater than 15mph
P0630 PCM vin not present
p17## Governor pressure sensor too high
P17## Governor pressure sensor too high or low
P0602 CheckSum Error

The accelerator fueling goes all over the place...cutting in and out and the gears shift at will quickly from 2,3,4 and back and forth all over the place.
Seems worse for shifting around 70mph, Throttle seems worse at lower speeds. Even when locked in 1st the truck revs to where it decides to be regardless of pedal positon.

Anyone who might have some insight into this to at least get me home....I do have the 04 ECM with me but it won't work till I burn in the SKIM key code.

I'm sure the 03 and 04 ECM pin pattern must have a difference in one or two pins. I thought the 03 had the pcm on the firewall which my truck does and the 04 had it in the ECM with no separate PCM module.

Oh by the way 75mph in 2nd is 4000rpm. ....not good when it happens all of a sudden when passing a car with a car passing with you behind you...not a good way to make friends.

When I reset the codes it will still do it and only the P0700 and p0720 reappear. Thanks for the help!!
KS

53 willys

bad speed sensor??? is what first comes to mind....I will be back in a few let me look i n the manual...............

53 willys

SYMPTOM
P0720-LOW OUTPUT SPEED SENSOR - RPM ABOVE 15 MPH

WHEN MONITORED
Continuously with the ignition on, engine running, and gear selector NOT in park or neutral.

SET CONDITION
This DTC will set if the vehicle speed (reported from the CAB module) is above 24 Km/h (15 MPH) , and the monitored Output Shaft Speed is below 60 RPM for 2.6 seconds .

POSSIBLE CAUSES

• Park/neutral DTC present
• Intermittent wiring and connectors
• Output speed sensor ground circuit open
• Output speed sensor signal circuit open
• Output speed sensor ground circuit shorted to other circuits
• Output speed sensor signal circuit short to ground
• Output speed sensor signal circuit shorted to other circuits
• Output speed sensor ground circuit short to voltage
• Output speed sensor signal circuit short to voltage
• Output speed sensor
• ECM

abc4yew

Mark, What does it say for the P0630...I think this may be the root of the problem....that speed sensor is that the one at the rear or on the tranny. Thanks, KS

53 willys

here it is.....

SYMPTOM
P0630-VIN NOT ENTERED ERROR

WHEN MONITORED
While the key is on.

SET CONDITION
The VIN was not calibrated into the ECM.



POSSIBLE CAUSES

• VIN not calibrated into ECM

Yes the speed sensor is on the back of the trans....
this is a tough one since you got this crazy conversion
I don't know if I should look up 03, 04 or 04.5????
do you think the smarty lost your Vin# some how???
did it happen right when you changed to SW5???

Since you cleared the codes and only the P0700 and p0720 reappear it makes me think speed sensor....I think they are only 20-30 bucks, it might be worth a try????

abc4yew

Mark, When I first operated the truck after the drop in it did the gear hunt thing once and all was good. This happened within 10 minutes of me changing SW from 7 to 5....I went back to 7 and still fubared so I went to 1 and still fubared. This problem went away when I changed it back to one the first time. If I remember right this sensor sometimes gets debris on it and goes wacky. I may pull it tomorrow morning and if its just dirty try it without dirt on it and go to the dealership where I am and replace it. That 630 is still puzzling to me. I was hoping Marco would have chimed in on that one. The governor pressure sensor high DTC might have happened when the revs went high on a 4 to 2 shift. Normally the tranny won't do this as the speed sensor is showing too high of speed to allow the tranny to shift down. No speed sensor truck thinks it is going slower than it is and shifts down even though rpms are high. Hmmmm. Speed sensor is the likely target then the ECM I guess. ks

53 willys

the test, for code p0630 is to program the Vin into the ECM with a DBR scan tool....if the code goes away then your good...if not you need a new ECM. so yes I would try the VSS first. They have been know to cause some really weird things to happen.

let me know what you find

Bob Wagner

Kerry, Marco is out of town for a few days. I will be back on tuesday. We should be able to provide a recovery software if need be.

I will get to Marco on tuesday. Let me know if you need anything else sooner.

N.Johnson

Kerry
It really sounds like the PCM is the problem. I know on mine I've had PO700code related occurrences since new. They didn't get rid of the PCM and incorporate the power train electronics control into the ECM till 04.5. My best guess from the all the codes it's giving you is the ECM and PCM stopped talking. Smarty always sets PO602 check sum error. Why is that? Bob or Marco should answer. A interesting Smarty thing is it sets codes in the PCM which show up when you hold the odometer reset button down and turn the key for the gauge cluster/light test thing. Smarty does not clear these codes I think because on the 03/04 the PCM is separate from the ECM. Bob I think we need help on this PCM thing and Smarty.

53 willys

Smarty and p0602 code info......https://www.dieseltruckresource.com/...ighlight=p0602

abc4yew

Well, I made it home and only a few bobbles. The VSS on my truck was covered in ATF+4 and the connector was fubared ... held together with a zip strip and the wires had been cut at one time....the tape was 99% gone and the wires were bare....probably when I went over a bump...they shorted out..... I jury rigged them for the trip home and I'm just heading out to pull the sensor and clean it up and then solder the wires directly to the sensor and cover them up with head shrink....I hope this cures this part of the problem. KS.