A friend of mine has a 2004 2500HD Duramax/Allison. The other day his check engine light came on, so he brought it over for me to scan it and see what was going on. It is showing a P0733--Incorrect Gear Ratio for 3rd gear.
While driving it and observing the data on a Modis everything appears fine. The input RPM is always 1.41 higher than the output speed sensor and the scanner even displays the observed gear ratio as being 1.41 which is correct for 3rd gear according to my information. I tried clearing the code, the engine light goes off but the code won't go away.
Also, I noticed while driving it that on the scanner, there is a spot where it says gear selected, this will vary from park, to reverse, to 3,4,5 all while maintaining a steady speed on the highway. I got underneath and inspected the electrical connector on the tranny and they all seem to be plugged in good and I see no obvious signs of damaged pins.
Any thoughts on what I have going on here? Range selector swtich? Trans control module? Wiring or ground issue?
Thanks
While driving it and observing the data on a Modis everything appears fine. The input RPM is always 1.41 higher than the output speed sensor and the scanner even displays the observed gear ratio as being 1.41 which is correct for 3rd gear according to my information. I tried clearing the code, the engine light goes off but the code won't go away.
Also, I noticed while driving it that on the scanner, there is a spot where it says gear selected, this will vary from park, to reverse, to 3,4,5 all while maintaining a steady speed on the highway. I got underneath and inspected the electrical connector on the tranny and they all seem to be plugged in good and I see no obvious signs of damaged pins.
Any thoughts on what I have going on here? Range selector swtich? Trans control module? Wiring or ground issue?
Thanks
