1999 SLK 230 Bypass Valve issues
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First question will be where did you get the K40?
K40s ideally need to be from MB, or a very trusted source.
We have seen many bought from ebay, Amazon et al that may not even work on arrival, or fail quite quickly.
Has the car worked at all since you fitted the new K40?
K40s ideally need to be from MB, or a very trusted source.
We have seen many bought from ebay, Amazon et al that may not even work on arrival, or fail quite quickly.
Has the car worked at all since you fitted the new K40?
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1,465 Posts
And the second Q, would be:
Do you have any other symptoms like explained by other users?
Search results for query: P1236
www.slkworld.com
Hey everyone thanks for the response the k40 was bought by someone else I think ebay. The car starts and runs great. Minus the SC issues. After disconnecti g the SC harness and unplugging the wires that run to the bypass valve I did get the bypass valve to work for few minutes. If I unplug the loom on the k40 for the SC the bypass valve moves for a second then stays put again. I don't think it's the k40. How can I teat the bypass valve itself?
Also I looked at k40 the board is perfect no hot spots solder looks great
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9,594 Posts
So have you checked the Bypass Valve and it's circuit ?
Can you close the flap with a scan tool? if yes try the steps below. I copied from somewhere.
If no check your wiring the connector is known to have a broken wire from engine torque.(my issue)
AF07.61-P-2000-01Ain recirculated air flap actuator
ENGINE 111.981 in MODEL 203.747
1 When ignition is switched off press flap slightly past limp home
position. (this is 90° position) must be changed manually from resting position.
(flap may close immediately then reopen) mine did not
2.Switch on ignition for approx. 15 seconds, switch ignition
3. back off again and wait for processor shut-off delay.
shut-off delay has a duration of approx. 5 seconds.
3. Switch ignition on for approx. 45 seconds, switch ignition
back off again and wait for processor shut-off delay.
The learn-in procedure for the recirculated air flap is then
completed
P.S. On the second step during the 45 seconds wait, you can actually see the flap close up automatically and then open up again - pretty much resetting itself.
What's the starting position?
I think I got it...
"90° position must be changed manually"
So, that means, push it, hard apparently according to E,
and knock it about 20 degrees off Kilter from straight up, and do the thang...
can't wait to try it tomorrow
I actually just closed the flap a couple of times, and because its spring loaded it goes back to its open position,
and then I moved to step 2, which was the ignition part.
You'll know when its working as an actual noise comes out of the valve,
and on the third step (which is the second time you turn on the ignition) my flap actually closed on its own and then opened, telling me that in fact it actually resettled itself.
So I did the flap reset the other day.
I held it slightly off 90 degree (normal position when the car is stopped)
while someone else turned the key.
It seemed to do the reset both times we had the ignition on.
It happens very quickly, opens and closes.
I tried doing it myself, but I have no idea if it worked...by the time you
get from turning the key to front of the car, no way to know if it did it already, so have a 2nd person helps.
I didn't notice a big diff on driving. And the position of the flap after it warmed up for 30-60 seconds (when it's completely closed...which leads one to ask, where the heck is getting air from during that time?)
was still at maybe 30 degrees at idle. I'm still not clear on the function of that flap. When open it pulls a mixture of fresh air, and exhaust off the
oil breather hose. When it's closed it.... ?????
Makes a funny sound! Like it's gasping for breath!
1. with Ignition of and air filter out; reach down to the Recirculating flap and put some pressure on it on the direction it closes (to the left)
2. Turn the ignition on and the flap closes; keep ignition on for 15 seconds. However the flap doesn't stay closed for 15 seconds but return after about 3 seconds.
3. Switch ignition off for 5 seconds.
4. Switch ignition on for 45 seconds.
5. switch ignition on for 5 seconds.
Start the engine. What I noticed is; the flap closes 70% of the way when idling but fully opens at higher RPM.
Not sure at this point if there is a fault with the Flap's servo or some other sensor is playing a part in this problem.
Read a few threads on resetting the Flap but no where I saw any info on how long it should remain closed and how it should behave under high RPM. It needs to closed under load/acceleration but how should it behave when the car is not moving. What other sensors play a part on the workings of the flap?
If no check your wiring the connector is known to have a broken wire from engine torque.(my issue)
AF07.61-P-2000-01Ain recirculated air flap actuator
ENGINE 111.981 in MODEL 203.747
1 When ignition is switched off press flap slightly past limp home
position. (this is 90° position) must be changed manually from resting position.
(flap may close immediately then reopen) mine did not
2.Switch on ignition for approx. 15 seconds, switch ignition
3. back off again and wait for processor shut-off delay.
shut-off delay has a duration of approx. 5 seconds.
3. Switch ignition on for approx. 45 seconds, switch ignition
back off again and wait for processor shut-off delay.
The learn-in procedure for the recirculated air flap is then
completed
P.S. On the second step during the 45 seconds wait, you can actually see the flap close up automatically and then open up again - pretty much resetting itself.
What's the starting position?
I think I got it...
"90° position must be changed manually"
So, that means, push it, hard apparently according to E,
and knock it about 20 degrees off Kilter from straight up, and do the thang...
can't wait to try it tomorrow
I actually just closed the flap a couple of times, and because its spring loaded it goes back to its open position,
and then I moved to step 2, which was the ignition part.
You'll know when its working as an actual noise comes out of the valve,
and on the third step (which is the second time you turn on the ignition) my flap actually closed on its own and then opened, telling me that in fact it actually resettled itself.
So I did the flap reset the other day.
I held it slightly off 90 degree (normal position when the car is stopped)
while someone else turned the key.
It seemed to do the reset both times we had the ignition on.
It happens very quickly, opens and closes.
I tried doing it myself, but I have no idea if it worked...by the time you
get from turning the key to front of the car, no way to know if it did it already, so have a 2nd person helps.
I didn't notice a big diff on driving. And the position of the flap after it warmed up for 30-60 seconds (when it's completely closed...which leads one to ask, where the heck is getting air from during that time?)
was still at maybe 30 degrees at idle. I'm still not clear on the function of that flap. When open it pulls a mixture of fresh air, and exhaust off the
oil breather hose. When it's closed it.... ?????
Makes a funny sound! Like it's gasping for breath!
1. with Ignition of and air filter out; reach down to the Recirculating flap and put some pressure on it on the direction it closes (to the left)
2. Turn the ignition on and the flap closes; keep ignition on for 15 seconds. However the flap doesn't stay closed for 15 seconds but return after about 3 seconds.
3. Switch ignition off for 5 seconds.
4. Switch ignition on for 45 seconds.
5. switch ignition on for 5 seconds.
Start the engine. What I noticed is; the flap closes 70% of the way when idling but fully opens at higher RPM.
Not sure at this point if there is a fault with the Flap's servo or some other sensor is playing a part in this problem.
Read a few threads on resetting the Flap but no where I saw any info on how long it should remain closed and how it should behave under high RPM. It needs to closed under load/acceleration but how should it behave when the car is not moving. What other sensors play a part on the workings of the flap?
Joined
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9,594 Posts
This is why SDS is virtually essential for anyone who wishes to seriously maintain older MB's.
The flap will also bypass the s/c If there is another fault, OBD machines do not see all of the possible faults.
Flap motor teach in procedure is also very easy etc etc etc.
The flap will also bypass the s/c If there is another fault, OBD machines do not see all of the possible faults.
Flap motor teach in procedure is also very easy etc etc etc.
That is called a Strategy Document, and is closely guarded by MB like Mother Theresa's knickers, I have friends at the factory, and even they couldn't get me the ones for V8 M113
Thanks for the info. I have a I carsoft 980. I don't believe it had the capability to manipulate the flap. I did the reset as the post instructed. It appears to have reset because when I restarted it and revved it up the flap closed for a second and then returned to the open position. Still same results stayed open and no supercharger noise. Back to sq one i ordered a used bypass valve on ebay and I'll change that next week when it comes In. But I'm starting to think ecm related? The wires to the bypass flap seem ok one has power one is a good ground
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I’m rising from the dead again, I’d also look at the valve itself.
I had one with a bad stepper motor. When recalibrating it, it would work again for a short while before inevitably getting stuck again. I think the ECU removes power from the valve when it notices it doesn’t move as it wants to, which causes it to spring back open.
I put a reman unit in it and haven’t had any boost issues since. Car runs great except for a slightly stumbly idle which I think is because it currently doesn’t have the correct types of plugs installed.
I had one with a bad stepper motor. When recalibrating it, it would work again for a short while before inevitably getting stuck again. I think the ECU removes power from the valve when it notices it doesn’t move as it wants to, which causes it to spring back open.
I put a reman unit in it and haven’t had any boost issues since. Car runs great except for a slightly stumbly idle which I think is because it currently doesn’t have the correct types of plugs installed.
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