Z06guy
NAXJA Forum User
- Location
- Sahuarita, AZ
Vehicle: 96 4.0 AW4 188,000 miles
Symptoms: With shift lever in OD, sometimes shifts normally, sometimes does not want to upshift. It sometimes stays in second gear up to 75mph. Most of the time it will upshift, but very late. It will also downshift out of over drive on the freeway for no particular reason. Sometimes it will upshift, downshift, upshift, downshift, and sometimes it will just downshift to third and stay there. Converter does lock up.
Testing: With TCM unplugged, it behaves properly, staying in whatever gear I leave the shift lever.
Fluid level is full and fluid color looks very good and smells fine.
Volt meter check of the plug showed everything reading properly with a few exceptions. First, I did not test the VSS input. I've read here that if it's bad, it won't upshift at all.
Second, C14-C16 all show ZERO ohms of resistance at the TCM plug and at the plug at the firewall. This is the part I don't understand. How can the trans shift even simi properly if all three solenoids were dead shorted to ground?
I tracked the little harness all the way to where it goes behind the transfer case shift linkage and don't see any destroyed or melted wires. I did notice at one point in the harness that the wires were a tad wet with tranny fluid inside the black plastic sheath which is odd because I don't have a tranny fuid leak.
Problems started on the trip home after a brutal 12 hour day of hardcore trail running in 105 degree heat. Vehicle was subject to heat, banging around, and a couple splashes through muddy puddles.
Any help you can offer me would be greatly appreciated.
Symptoms: With shift lever in OD, sometimes shifts normally, sometimes does not want to upshift. It sometimes stays in second gear up to 75mph. Most of the time it will upshift, but very late. It will also downshift out of over drive on the freeway for no particular reason. Sometimes it will upshift, downshift, upshift, downshift, and sometimes it will just downshift to third and stay there. Converter does lock up.
Testing: With TCM unplugged, it behaves properly, staying in whatever gear I leave the shift lever.
Fluid level is full and fluid color looks very good and smells fine.
Volt meter check of the plug showed everything reading properly with a few exceptions. First, I did not test the VSS input. I've read here that if it's bad, it won't upshift at all.
Second, C14-C16 all show ZERO ohms of resistance at the TCM plug and at the plug at the firewall. This is the part I don't understand. How can the trans shift even simi properly if all three solenoids were dead shorted to ground?
I tracked the little harness all the way to where it goes behind the transfer case shift linkage and don't see any destroyed or melted wires. I did notice at one point in the harness that the wires were a tad wet with tranny fluid inside the black plastic sheath which is odd because I don't have a tranny fuid leak.
Problems started on the trip home after a brutal 12 hour day of hardcore trail running in 105 degree heat. Vehicle was subject to heat, banging around, and a couple splashes through muddy puddles.
Any help you can offer me would be greatly appreciated.