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GLA 45 Race Start 4Matic currently unavailable

2257 Views 8 Replies 6 Participants Last post by  2017GLA45AMG
It seems like the only person who can help me now is Jesus. I have been having this issue ever since I went stage 1 tune from eurocharged. If I do race start on my 2017 GLA 45, I would always get this message "4matic currently unavailable" at the end of first gear when it's about to shift to second. I have tried EVERYTHING. Since everyone talks about wheel spin being the main culprit, I got wide tires, lowered the psi to 22, warmed up the tires, nice hot day, and prepped the track with sticky substance. It hooked incredibly but again, at the end of 1st gear when it's about to shift to second, it cuts off power completely and says "4matic currently unavailable". At this point I have 2 options, either I let off and or stay in it and after 3 seconds it goes back to being a rocket. I currently have stage 2 tune and TCU tune with eurocharged. The shifts on race start are INSTANT.. when I stay in it after the message. I don't know what's causing this issue. My buddy has a 2018 CLA 45, same exact tires, same tune ECU and TCU, same road, same time launching it, same spinning, but his doesn't cut off, mine does. I can only brake boost if I want to "drag race", that will not cut power, but it does not kick as hard or shift instant like race start does.

What is causing this issue??????????
Is it a bad battery? (It has been previously replaced with another OEM, weird for a 2017 car)
Is it bad wheel sensor?
Is it second gear clutch slipping?
Is it a bad rear differential?
Is it software or hardware??

I have no fkin clue. I'm sick and tired of this BS. The launch control is where this car should shine and I can't even do it.
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That does suck. If I were you I would be taking steps backward on my mods until, if necessary, your back to stock. If it still won't launch with no mods then you have a case with MB.

My process is so what's cheapest and easiest first. I'd get rid of the tune to start.
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I have read something about when someone increased their red line, they had issues with launch control. I can try to get a video of this happening
It seems like the only person who can help me now is Jesus. I have been having this issue ever since I went stage 1 tune from eurocharged. If I do race start on my 2017 GLA 45, I would always get this message "4matic currently unavailable" at the end of first gear when it's about to shift to second. I have tried EVERYTHING. Since everyone talks about wheel spin being the main culprit, I got wide tires, lowered the psi to 22, warmed up the tires, nice hot day, and prepped the track with sticky substance. It hooked incredibly but again, at the end of 1st gear when it's about to shift to second, it cuts off power completely and says "4matic currently unavailable". At this point I have 2 options, either I let off and or stay in it and after 3 seconds it goes back to being a rocket. I currently have stage 2 tune and TCU tune with eurocharged. The shifts on race start are INSTANT.. when I stay in it after the message. I don't know what's causing this issue. My buddy has a 2018 CLA 45, same exact tires, same tune ECU and TCU, same road, same time launching it, same spinning, but his doesn't cut off, mine does. I can only brake boost if I want to "drag race", that will not cut power, but it does not kick as hard or shift instant like race start does.

What is causing this issue??????????
Is it a bad battery? (It has been previously replaced with another OEM, weird for a 2017 car)
Is it bad wheel sensor?
Is it second gear clutch slipping?
Is it a bad rear differential?
Is it software or hardware??

I have no fkin clue. I'm sick and tired of this BS. The launch control is where this car should shine and I can't even do it.
Hey, first thing that pops to mind is the wheel speed sensors reporting numbers that didnt add up.

Take steps to ensure the functional tire diameter is equal all around, and within the alarm point delta what the ECU has stored as reference
Problem solved. It was the Eurocharged stage 2 tune that was causing the issue. I went with a complete custom tune based off of my original map and it fixed my issue.
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Good stuff.

What do you use race start for? I hear it's tough to time for drag racing, and it's not use for tracking at least with HDPE or org hobby time trials.
I use race start for fun when there's no traffic around, hahaha!
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Problem solved. It was the Eurocharged stage 2 tune that was causing the issue. I went with a complete custom tune based off of my original map and it fixed my issue.
How much did you pay on top of the tune you had previously? I’m stage 2 eurocharged rn and questioning if I should do a tcu tune or if there is a better option that is worth it.
How much did you pay on top of the tune you had previously? I’m stage 2 eurocharged rn and questioning if I should do a tcu tune or if there is a better option that is worth it.
You can use the TCU tune from ECC but do not use their off the shelf ECU tune. Lots of issues there. Better to get a custom tune for your car. Every car is different, especially with specific mods you have.
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