I do have another thread (with too many words!) where the traction control relay was causing all sorts of fun stuff to happen. (Other thread) The repaired / refurbished RCM (with trac ctrl relay replaced) is now in the car. (Thanks to tighed1)

It will not shift from park unless I override it with a tool through the slot. The shift indicator on the display does show P for park. If I override, all shifter positions are displayed correctly. Once in Drive, I cannot put it back into reverse without shutting the car off and trying again with override - Or, removing the tool from the slot - that seems to let it shift back into reverse or park.

Brake pedal switch is new, but I did not have it installed when I replaced the RCM and started the car. Generic code scanner was throwing a P0600 generic CAN bus comm problem? I don't have a merc scanner. Crazy question, how many sets of wires should be going to the brake pedal switch? I only found one plug into the switch, but there are two receptacles on the switch.

Is there an brake interlock solenoid under the hood, or at the shifter, transmission control module in passenger footwell? Had the center console apart enough to see that the shifter assembly is dry - I don't think water is an issue, never had a spill there. This problem happened roughly the same time as the RCM needing repair. I was stuck with no crank no start, and once it did start, couldn't shift into drive. Fussy little booger.

Ideas??

 

Update - I took it for a ride this evening and everything behaved well, except for needing to use the tool to bypass the locked out shifting lever. Crazy.

I read in a post HERE post658948 that there is a manual adjustment to the interlock. Is this my next step? I've read a lot of people have this problem and it is cured with a repaired RCM (seems common, but I just had that done) also read a lot of people who had this problem ended up replacing the entire shift assembly (which seems crazy - it's an 05, with under 34k on the clock.)

I get it, they're finicky. I'm calling this domestic exotic. Merc repair bills dressed up in a Chrysler suit. ?? Frustrated here.

 

From the ServiceManual
Brake Transmission Shift Interlock
BTSI is a safety feature that enables the shift selector lever to stay locked in the Park position when the brake pedal
is not depressed (ignition on) or when there is no current present in the Shift Lever Assembly. If the Shift Lever
Assembly selector lever cannot be shifted from the Park position due to a mechanical or electrical failure, the selector
lever can be released from the Park position using the shift lock override procedure. To do this, insert a long
screwdriver into the notch just below the “-D+” symbol on the Shift Lever Assembly and depress the lock button
while moving the selector lever out of the Park position at the same time. This will allow the shift lever to be manually
moved out of the Park position in order to move the vehicle.

Could the brake switch on the brake pedal be faulty and failing to power the solenoid on the gear changer?
Or is there something wrong in the electrical circuit, faulty solenoid, wiring etc.?
Replacing the gear changer is required if the solenoid is faulty as it is not repairable according to the Service Manual, but they say that about lots of things which can be fixed.

 

I've been able to use the override for the interlock to take it for a drive. It worked fine. I neglected to mention that there is a new Mercedes brake switch installed above the brake pedal - I picked that up from a local dealership 2 weeks ago. Had this issue combined with the no crank, no start problem recently. That switch has only one of the two plugs in use. Thought that was odd, but maybe one is for diagnostics? I have tried the old switch, and the new switch both, no difference.

Possible that it is solenoid having trouble. Can that be visually inspected if I pull the trim ring and bezel off the top of the shifter? Manually close it?

My RCM just had all solenoids replaced (except horn) by tighed1. I'd like to find someone local with a code reader, or pick one up that could read the codes. Torque app on my phone and a generic bluetooth scanner only pulls P0600, I understand there probably are other specific codes stored.

Thanks onehundred80!

 

Quick update - still stuck, using the bypass to let me put it in gear.

I have not scanned for codes, and yes, that would be a good idea. I was hoping "throwing parts at it" would make it work. Not a great idea. Bought a shift assembly off eBay, removed the existing and installed that one. Lots of hassle there, but it's done. NO CHANGE. Still stuck in park. Let that be a lesson to others - root cause diagnosis still unknown.

I do only have one plug connected to the Brake Pedal Switch, there isn't a second plug, although diagrams that I have seen show 2. ?? I have read in other threads that some Crossfires have no pedal switch. So maybe it's not unusual to only have a single plug on mine?

Suggestions for next steps? I really did not want to go to a dealer to have the codes read. Is there an inexpensive code reader that would get me over the hurdle that I would also be able to use for non Mercedes products? Everything else I own is domestic, and I'm not sure how long I'll end up keeping the Crossfire. Don't get me wrong, it's a blast to drive, but the issues I've had in less than a year make me question my sanity for thinking that I should keep it, I wanted to enjoy it for a complete season, and decide. On a plus note, by the time I finish fixing all the quirks, it'll probably be super-reliable for someone else! :-)

Thanks all, and Happy Sunday!
DadsXF

 

 

Thanks onehundred80, I did see that previously but haven't pursued it. I'll look into it when I build up my patience level again. It's a pain in the butt getting access to the shifter, I didn't complete;y remove the center console to replace it. I'll look again at the adjustments, right now, I have a "spare" outside the car, so I can look it over.

Thanks,
DadsXF

 

Really need a scanner but believe there is wired connector and a can-bus connector. The P0600 tells me that the Can-Bus is not connected. Am surprised it shifts through all the gears., usually with no comm I won't shift up. Does make me wonder about the shift lock solenoid.

 

Update - found a promising local shop that specializes in Mercedes, but they want no part of a Crossfire. I wasn't offended, but I was hoping they'd at least let me pay them a fee to read the codes. Nope. Nada. Found another shop a little further away, pending a reply from them - they specialize in luxury vehicles / imports (lots of reviews from BMW and Mercedes owners). Sounds like it'll be pricey to me! Will keep you all posted. Thanks again everyone, DadsXF

Also - onehundred80 - the adjustment procedure mentions that you are supposed to "supply current to the solenoid" when making the adjustment. Any ideas for "how" to do that? I assume maybe step on the brake with key on while trying to make the adjustment? Also, for what it's worth, stepping on the brake, I hear a click near the brake pedal, but nothing heard or felt in shift **** / gear selector area.