Why Shifter Lever Assy breaks on Jeeps
After several short term "limp modes' followed by famous 'circled" PRND on EVIC decided to check SLA module, also known as electronic shifter module (ESM), inside. Several people here claimed that after replacement of SLA module they got rid of the problem.
I started with some homework and found German (Mercedes) white papers about 722.6 gearbox. Documents stated that inside the module there are 12 Hall sensors to detect lever position. Hall sensors are known as pretty reliable ones cause they are contact-less sensors. Interestingly, I didn't found any claims on SLA module on several Benz sites.
However when I disassembled SLA module, I found that Chrysler put cheep mechanical contact system inside instead of just a bit more expensive but far more reliable Hall sensor system.
My guess is that it might be a main reason of SLA module failures. Most of them are reported at 30K-40K mileage, right after starting the car in cold mornings. Morning condensation along with a sufficient amount of conductive material accumulated between lamelles may cause position misreading.
The good thing is that it's possible to clean them using contact cleaner, which I did. By the way Chrysler says that it's non serviceable unit and wants more than 300 bucks for part only.
This is picture of PCB
These are lamelles before cleaning
Contacts are different - gold plated for gear position and nickel plated for autostick
I think that's one of a good examples, why Chrysler cars have worst reliability figures than Daimler ones.
Black GC SRT8, 2006
Dashhawk, rear fogs mod, double shocks at rear, Philips LED DRL, Muth mirrors, upgraded audio
Black Toyota 4runner, 2003, Ltd, AWD, V8
X-REAS, K&N CAI, Magnaflow exhaust, Unichip, JAOS skidplate, Muth mirrors, rear fogs mod, front fogs mod, low beam HIDs, upgraded audio
Last edited by a137; 09-28-2009 at 05:19 AM.