Hunter013
Well-Known Member
Cat 725 S/N: B1L02639
Operators said on Friday, the truck lost first gear forward. They shut it off, let it sit, and it worked fine the rest of the day. Monday morning they called me saying they lost reverse, but had forward gears. I went out to troubleshoot it in the field. It had a list of codes pertaining to the torque convertor and trans output sensors. If it idled for while, I lost forward gears. I had it brought back to the shop. The lowboy driver said it drove itself up to the ramps, but he lost forward gear right as he hit the ramps. We dragged it into the shop and we started looking at the wire harnesses and sensors and didn't see anything abnormal. I don't necessarily know which codes to start with troubleshooting wise. The truck also got a new trans/chassis ECM about 2 years ago, and a new Engine ECM within a couple months.
The action alarm code is just because it was unplugged for while, and the turbo inlet sensor was unplugged for separate maintenance on the engine.
The trans filter plugged code came on and off for awhile (you can see in the logged event codes). The filter was changed at least twice since it first appeared. Nothing bad was ever found in the oil/ filters.
The only active codes were for the "trans oil temp sensor: (I think) below (possibly above) normal". But it would flicker from active to not when you would use the shifter.
Any suggestions on where to start would be appreciated.
Operators said on Friday, the truck lost first gear forward. They shut it off, let it sit, and it worked fine the rest of the day. Monday morning they called me saying they lost reverse, but had forward gears. I went out to troubleshoot it in the field. It had a list of codes pertaining to the torque convertor and trans output sensors. If it idled for while, I lost forward gears. I had it brought back to the shop. The lowboy driver said it drove itself up to the ramps, but he lost forward gear right as he hit the ramps. We dragged it into the shop and we started looking at the wire harnesses and sensors and didn't see anything abnormal. I don't necessarily know which codes to start with troubleshooting wise. The truck also got a new trans/chassis ECM about 2 years ago, and a new Engine ECM within a couple months.
The action alarm code is just because it was unplugged for while, and the turbo inlet sensor was unplugged for separate maintenance on the engine.
The trans filter plugged code came on and off for awhile (you can see in the logged event codes). The filter was changed at least twice since it first appeared. Nothing bad was ever found in the oil/ filters.
The only active codes were for the "trans oil temp sensor: (I think) below (possibly above) normal". But it would flicker from active to not when you would use the shifter.
Any suggestions on where to start would be appreciated.