SL/R230: Check Engine / Transmission
#1
Junior Member
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Check Engine / Transmission
Thanks to this forum, I've enjoyed 2 months and about 1200 miles of some of the most fun I've had in a car. I"m not a car guy, but trying to learn.
The other day when driving I noticed the car felt sluggish and I looked at the Tach and it was 3500 or so and would not shift into the highest gear. I slowed way down, tried to move it to manual and it stayed in D. When I accelerated again, still would not shift into high gear.
I pulled over, shut the car off - Re-started it and it was normal for the next few hundred miles.
Yesterday, it did it again. Again could not go into manual mode. (Reboot helped). Later, I did get a significant "bump" when shifting (in automatic) from 2-3 like getting tapped on the rear end. One time, no other issues.
It did it agin today, and also when driving in manual it wouldn't shift out of 2 and the Check Engine light came on.
Since owning this car, I did have my local mechanic do a transmission flush a month ago. I have not checked the fluid, I do not have a scan tool.
Can you point me to some possible things to explore. I'm taking it to the shop tomorrow - (it's about a 10 mile drive - should I tow it, or drive it?)
2003 SL 500 / 70,000 miles.
The other day when driving I noticed the car felt sluggish and I looked at the Tach and it was 3500 or so and would not shift into the highest gear. I slowed way down, tried to move it to manual and it stayed in D. When I accelerated again, still would not shift into high gear.
I pulled over, shut the car off - Re-started it and it was normal for the next few hundred miles.
Yesterday, it did it again. Again could not go into manual mode. (Reboot helped). Later, I did get a significant "bump" when shifting (in automatic) from 2-3 like getting tapped on the rear end. One time, no other issues.
It did it agin today, and also when driving in manual it wouldn't shift out of 2 and the Check Engine light came on.
Since owning this car, I did have my local mechanic do a transmission flush a month ago. I have not checked the fluid, I do not have a scan tool.
Can you point me to some possible things to explore. I'm taking it to the shop tomorrow - (it's about a 10 mile drive - should I tow it, or drive it?)
2003 SL 500 / 70,000 miles.
#2
MBWorld Fanatic!
My first guess would be an accelerator pedal fault. This will cause a limp mode which will limit power and gear changes. I haven't tried to use manual mode in this limp mode, but it makes sense that it would be disabled. If it drive normal after a key cycle, I wouldn't have any issue driving it to the shop.
#3
Junior Member
Thread Starter
My first guess would be an accelerator pedal fault. This will cause a limp mode which will limit power and gear changes. I haven't tried to use manual mode in this limp mode, but it makes sense that it would be disabled. If it drive normal after a key cycle, I wouldn't have any issue driving it to the shop.
#4
Junior Member
Thread Starter
My first guess would be an accelerator pedal fault. This will cause a limp mode which will limit power and gear changes. I haven't tried to use manual mode in this limp mode, but it makes sense that it would be disabled. If it drive normal after a key cycle, I wouldn't have any issue driving it to the shop.
it drove completely normal the whole way there. The check engine light was on - I’m assuming it’s persistent once it’s activated until reset?
#5
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Join Date: May 2020
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2004 SL500AMG, 2003 SL500 USA
I just found the accelerator problem, which is the TPS (Throttle Position Sensor) problem seriously caused my 7 speed to malfunction. I pressed the accelerator pedal and the rpms would only slightly increase. After a stop it might gain rpms more like normal intermittently. Before the TPS sensor symptoms were noticeable I had transmission problems occasionally limp mode. I occasionally left the negative battery cables disconnected overnight several times to enter transmission training mode. That kept me out of limp mode but i still had shifting problems. I just replaced the accelerator pedal assembly, and the tranny seems to be working well.
Last edited by aegea; 06-17-2024 at 10:20 PM.
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TxBenzIn (06-17-2024)
#6
Junior Member
Thread Starter
I just found the accelerator problem, which is the TPS (Throttle Position Sensor) problem seriously caused my 7 speed to malfunction. I pressed the accelerator pedal and the rpms would only slightly increase. After a stop it might gain rpms more like normal intermittently. Before the TPS sensor symptoms were noticeable I had transmission problems occasionally limp mode. I occasionally left the negative battery cables disconnected overnight several times to enter transmission training mode. That kept me out of limp mode but i still had shifting problems. I just replaced the accelerator pedal assembly, and the tranny seems to be working well.
do you have a part number in case I end up down that road?
Last edited by TxBenzIn; 06-17-2024 at 11:20 PM.
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#8
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2004 SL500AMG, 2003 SL500 USA
Last edited by aegea; 06-18-2024 at 08:46 AM.
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TxBenzIn (06-23-2024)
#9
Junior Member
Thread Starter
My first guess would be an accelerator pedal fault. This will cause a limp mode which will limit power and gear changes. I haven't tried to use manual mode in this limp mode, but it makes sense that it would be disabled. If it drive normal after a key cycle, I wouldn't have any issue driving it to the shop.
https://www.fcpeuro.com/products/mer...e-1402700861oe
Good as New!
#11
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