Well more issues with this car it never seems to end.. Here again because I'm at a loss. Drove the car two weeks ago slept over a friends house, next morning went out to start the car 3 cranks no start, then no crank. Figured my skeem finally went.. Pulled the ECU, Skeem and sent my key off to Mercedes swap shop. They re-cased my key, reprogrammed all my stuff and said they bench test in a car 30+ times to insure starting. I just got it back today. Threw it in the car and same symptoms. (my battery was pretty much dead, we threw it on a jump pack same 3 crank no start I'm getting the battery charged tomorrow as its not even 2 months old) I'm wondering what to even do at this point, I've made sure the connections to the ECU are seated properly along with the Skeem. Checked the wiring on the antenna seems to be fine. I'm wondering if I should replace the antenna? Unrelated symptoms just to put everything into perspective my central locking pump I replaced a while ago worked fine, unlocked and locked from the dash as well as the fob. Now I checked and fuse 25 was blown, the pump only unlocks now from the dash but I'm assuming this is unrelated to starting because I've had the entire pump out and the car still ran and drove fine. I checked the wiring for corrosion and there is no water in that area. Also my key will not re synch I've tried multiple times and nothing is working (yes the batteries are new and I see the red light in the fob when pressing the button) If anyone could please point me in the right direction I'm ready to rip my hair out.

 

Hi Mike,
when you say antenna, do you mean the pickup ring that goes around the ignition. If you take the C3 connector off the SKREEM and measure the resistance between pins 1 and 2, they should be connected, and probably measure less than 100 ohms (manual is a little confusing since it talks about cavity 1 to cavity 2, which I think means on the SKREEM because otherwise why turn the ignition on?). Also, are there any DTC error codes? It sounds like the antenna ring might be bad. There are cheap devices for sale that can tell you if the antenna is emitting a signal.
-Jerry


Diagnostic Test (page 8Q-41)
1. MEASURE THE RESISTANCE OF THE SENTRY KEY ANTENNA CIRCUIT
Disconnect the Sentry Key Antenna Ring connector from the
SKREEM.
Turn the ignition on.
Measure the resistance of the Sentry Key Antenna circuit from cavity 1
to cavity 2 of the connector.
Is the resistance between 4 and 6 ohms?
Yes >> Replace the Sentry Key Remote Entry Module.
Perform SENTRY KEY VERIFICATION TEST.
No >> Replace the Sentry Key Antenna Ring assembly.
Perform SENTRY KEY VERIFICATION TEST.

From the manual:
The Sentry Key Remote Entry Module (SKREEM) has the following functions: receiving and evaluating the Radio
Frequency (RF) keyless entry remote signal, actuation of door locks in conjunction with the Central Locking Pump/
Security System Module, and enabling the vehicle theft security alarm with confirmation via the turn signals. When
the RKE transmitter is operated, an RF signal is transmitted. If the SKREEM recognizes the RF signal as valid, it
actuates the Central Locking Pump/Security System Module through the Body Control Module. The vehicle is then
locked or unlocked through the power locks system. Connected to the SKREEM is a Sentry Key Antenna Ring
which surrounds the ignition lock cylinder. When the ignition is switched on, the Sentry Key Antenna Ring is supplied
with power. A data block is transmitted inductively via the Sentry Key Antenna Ring to the SKREEM and then
on to the Powertrain Control Module. If the antenna ring data block content is invalid or if vehicle battery power is
too low to build up enough power for the antenna ring, the Powertrain Control Module will not receive the proper
signal. This is displayed with the message “Start Error” in the Instrument Cluster.
The SKREEM contains an RF transceiver and a microprocessor. The SKREEM transmits RF signals to and receives
RF signals from the ignition key transponder through a tuned Sentry Key Antenna Ring that is wired to the
SKREEM. If the Sentry Key Antenna Ring is not mounted properly around the ignition lock cylinder housing, communication
problems between the SKREEM and the ignition key may arise. These communication problems will
result in ignition key transponder-related faults. The SKREEM also communicates over the Controller Area Network
(CAN) data bus with the Powertrain Control Module (PCM), the Instrument Cluster, the Body Control Module (BCM),
and/or the DRB IIIT scan tool.

 

Also, for what it's worth, a weak battery can cause all kinds of issues. Have you disconnected, replaced the alarm siren? It has batteries that short out and drain the starter battery? It is also possible to get a defective starter battery, new or not.

 

Yes sorry that's what I meant by antenna thanks for the info I'm going to go head and give that OHM test a try between those pinouts there are no DTC codes. I'm trying to source a used ring from a local junkyard because I'm in a pinch and need this to work asap. If those pinouts read correct looks like I'll have to bite the bullet one last time and grab a new one from needswing. Thanks a lot for the help!

 

I have not gotten around to replacing that or disconnecting it I need to stop being lazy and get it taken care of because it has forsure been parasitically draining my battery. I'm going to get it charged and tested for a bad cell now and go from there thanks z!

 

Low voltage can also damage your screem. I would start there. Also, it is recommended to always disconnect the negative first and re-attach it last.

 

Just got the battery back, fully charged no bad cells it's only a few months old. Same symptoms I disconnected the antenna ring and ohm tested between the two terminals and got no reading seems to be bad. Going to try to pull one from junkyard or order another. Hopefully this is the issue!

 

Well no go on the antenna, replaced and same thing 3 crack no start sending back to MSS to test the skeem ecu and key. Just to note the battery was just low when I first tried to start this like 11.8 still cranked the 3 times just nothing happened

 

Hi Mike,
If you're sending the system back to MSS, also include the antenna so that there is no question as to whether it all works together.
-Jerry

 

Hey jerry thanks for the advice as always but I've already sent the unit back to MSS I did end up just purchasing a new antenna from needs wings to hopefully fingers crossed this was just some mess up on there end but I'm sure they'll make it right if so! Until then I'll be biting my nails lol

 

Well, more great news. They bench tested my skreem, key, ecu, and it all checked out at MSS. MSS suggested at this point to look at the RCM, pulse module, fuse block and ignition. I'm at a total loss atp I always thought 3 cranks no start has been skreem related so its hard to think anything like that would be an issue. He did confirm when I set back the unit that the skreem was bad. The RCM was reflowed last year, the pulse module was inspected when I replaced my starter. At this point I have zero idea what could possibly be causing this. I shut my car off one day and it just never turned back on lol.

 

Reflowing the RCM does not mean it is good. The relays wear and fail. Replace it and have DJ rebuild the old one and keep it for a spare.

 

Got it thanks Z, curious as to where I purchase one? Also does anyone have DJ's contact? Whats your opinion on the RCM causing the 3 cranks no start I havent seen anything on the form related to another module besides the skreem and ignition system.

 

Email tighed1@hotmail.com

 

Valk gave you DJs contact and you can purchase them from Amazon or needwings and others. Most of the mechanical parts are interchangeable with a 2003 Mercedese SLK 320.

 

Hi Mike,
when you say 3 cranks and then nothing - does the car start for like 10 seconds in between the 3 tries, or does the engine only turn over 3 times and never starts? What's your battery voltage as you try to start the car? Does it go very low after 3 cranks? (Just grasping for straws since it looks like the SKREEM isn't the issue.)
-Jerry

 

I'm going to do a deep dive once my skreem gets back in the next day or two, its hard to remember I think it was sporadic if I remember right the car would just start sputter out in about two seconds 3 cranks then nothing. (Same thing happened when I forgot to put my little chip back in when I recased also why I believed it to be the skreem module. MSS confirmed though the sckreem did need a reflash when it hit his bench. I'll have to double check on that battery voltage I brought it to orileys they charged and tested it said all cells where good and it charged to full its not very old either think 3 or 4 months.

 

Hi Mike,
Okay, the crank, start three times does seem to indicate the issue is something to do with the SKREEM circuit. One option to keep in mind is getting the ECU reprogramed to bypass the SKREEM if nothing else works out.
-Jerry

 

Thanks jerry is this something MSS does? I'm going to try and do my best to dive into this circuit once I get the part back Thursday and go from there.

 

Hi Mike,
here's one website that does the reprogramming: 2004-2008 Chrysler Crossfire ME2.8 Immobilizer (SKREEM) Delete Service — Precision ECU. Looks a little pricey, but there may be others that are cheaper. You can also get a used SKREEM, and send it to reprogrammer with your ECU (maybe MSS does this, not sure): 2005 Chrysler Crossfire PCM | ECM | ECU | 3.2L | VIN Programmed & Updated
-Jerry