elzyata,

welcome again to the forum, and thank you for creating a separate thread about a subject that I believe has not been covered yet on this forum.

This is to qualify my input below: I know the Crossfire convertible top hydraulic system very well, but I am not an expert on Crossfire DTC code reading or diagnosis based on DTC codes. My knowledge of DTC codes comes strictly from reading the service manual.

I have a few questions that may help in steering this thread into the direction of fixing your problem most cost effectively. The solution may be easier than replacing the travel sensors, or it may be more complicated.

1) Apparently, you have had someone with specialized equipment (DRBIII) read DTC codes. Was it your dealer?
2) Did they give you a print out of the codes, or did they give you the information above verbally? There must have been a code number with the rear bow cylinder related sensor?
3) In which direction was your top moving (if it stopped working while moving), and exactly at what point during the movement did it stop?
4) Has any work been done to your top system lately, or did this happen after the inside of the car was somewhat wet?
5) Was your top moving more slowly lately?

The Crossfire roadster top has five travel sensors, also known as hall-effect sensors. They react to magnetic field change, which is sensing the movement (travel) of the pistons in the hydraulic cylinders that they are mounted to. There are two sensors per left main lift cylinder 5142639AA and two sensors per left rear bow cylinder 5142640AA, which are all serviced together. That means all four sensors are tied into one assembly. You could theoretically replace single sensors by splicing the harness, if you are sure that you have found the cause. There is one travel sensor on the top (rod end) of these cylinders, and one on the bottom (base). The fifth travel sensor is on top of the tonneau cover cylinder 5142641AA. This one is part of the pump wiring harness (yikes - you definitely want to fix this one by splicing, if needed).

The travel sensors themselves rarely go bad - it is more commonly a wiring issue or a loose/corroded connector.

The reason for question 1) and 2) is that your description of code 9902 does not match exactly what I read in the service manual. The service manual describes code 9902 as "Main Cylinder Travel Sensor Rod Side Stuck". Each sensor (top or bottom) can give a "stuck" or "inoperative" code. If you have two sensors stuck at the same time, then I would suspect a wiring issue in the travel sensor harness, or a corroded connector, or a low hydraulic fluid level from one or more cylinders leaking.

Looking forward to your detailed response,

Klaus

www.tophydraulicsinc.com