Hello, and Thanks in advance for the assistance. Generally I have no problem troubleshooting or working on a vehicle, however this P1601 code has cropped up with very little support through googling or forum searching. It seems to relate to a (supercharged only) jgate transmission sensor to detect shifting patterns in the manual mode for the 2-4 range modes on the mercedes tranny. Any one have any input?

The car shifts a bit more harshly, grabs very firmly now in a decelerating downshift (driving down hill with foot slightly on brake) but still allows manual selection on gears 2-4 and shifts on command of movement through them.

This is a lone code, it is not supported by any other codes.

Apologies, 1999 XJR 103,000 miles, zero other problems.

 

Here is some info for you to look at.

bob gauff

 

The vehicle had a check engine light on for around 6 days with the aformentioned P1601 code. Last nightduring standard driving (50mph) cruising, Traction control fail, Stability COntrol Fail, and Engine Failsafe Mode were triggered. It also gave a P1612 code (throttle offset malfunction) along with a P1000 code. Vehicle died twice on the way home, yet started back immediately, although it ran very rough. I limped it all the way home, turned it off, pulled the codes, cleared them, (this time they actually cleared and did not come back up immediately and the car ran beautifully.) Voltage was 11.94 at the front fuse box with the car off, and 12.2 with the vehicle on. I am going to get a stress test on the battery and possible replace (legnth of time in service is unknown) and the test to see if the alternator is recharging properly. Perhaps a simple voltage descrepancy is causing most of these problems.

If anyone has any experience with the P1612 code, please chime in. Both the P1601 and P1612 seem to be rather rare codes.

I will be checking the TCM connections, and cleaning the Throttle Body position sensor as well to attempt to remedy the codes. Lastly I will check the Tranny sensor on the Jgate to check for loose connections, or mounting.



Also Thank You to Bob Gauff for providing the helpful documentation above!