Limp Mode

[Ccantine]

First time poster here. 2004 International with a t444e and Allison 2000 transmission. I’m stuck in limp mode - reverse and 3rd (i think). I’m throwing a 141 code. I replaced the output speed sensor but still stuck in limp. I don’t have the scanner to clear the code, so I’m not sure if the computer “knows” i changed the sensor. I tested the battery to see if the alternator was pumping what it should, but it’s only reading 13.85 with engine running. Not sure if that is acceptable, and if not, if that is contributing to the problem. I’m open to suggestions. Appreciate the help.

[musigenesis]

No expert but I found this: T444E Engine Control System

141 Vehicle Speed Signal Out Of Range Low

I dunno what that means.

Edit: I guess you knew this already, since you replaced the speed sensor.

[musigenesis]

Also found this T444E diagnostics manual (warning, very large, probably don't want to download it on a phone): http://www.blackwire.com/~bjordan/Te...0optimized.pdf

The section on 141 says this:

FLASH CODE 141
ATA CODE PID 84 FMI 4
VPM: VSSORL

This code is set when the VPM detects an
out-of-range low (ORl) signal from the vehicle
speed sensor.

WIRING CAUSE: VSS Sensor circuit between the
VPM and Sensor, shorted to ground or open.

If this code is active, perform Testing VPM to Sensor
Circuits on page 241 .

The test on pp 241-242 is pretty long and complicated, but it doesn't make any mention of having to clear the code; seems once the problem is fixed the code will clear itself?

[cadillackid]

so you are in LIMP and no VSS to the computer.. the VSS signal on the 2004 is provided not by the sensor directly but by the TCM.. I would bet that either you lost a Trans / TCM fuse or wire.. or your TCM is bad altogether. so that the VSS signal is Low out of range throwing the 141 code on the IH side.. that 141 is an IH code not an Allison code..



I would start with Trans fuses and TCM wiring.. 13.8 volts is very normal.. in fact its nice N high..

[Ccantine]

Thank you. Excuse my ignorance, but can you point me to what the TCM is and where i can find it. Also, would the transmission fuses be in the main fuse panel? Appreciate the help.

[cadillackid]

if this is a conventional bus the trans fuses are in the panel on the dash (not the one on the outside under driver window).. they should be labelled as Transmission and / or driveline.. there are 2 of them if I remember right.

[Ccantine]

Thank you. I’ll look for them tomorrow.

[magnakansas]

nice work man.

william

[Ccantine]

It’s working. Turns out is was a 10 amp fuse labeled Elect Trans Feed in the chassis fuse block. One of those ones where you can’t tell it’s blown without testing with multimeter. Thank you so much for your guidance - much appreciated.

[Native]

Way to go, Cadillackid!

[mmoore6856]

good work but this makes me glad i am obd free.

[Native]

Originally Posted by mmoore6856

good work but this makes me glad i am obd free.

So is the OP ...buses run J1939 with some J1708, not OBDII.