SL R129 Roll bar will not retract

[ADP]

Until the fault code has been reset you're stuck. If the sensor is just on/off then either the wiring is dodgy or the ECU has a problem if it's generating this fault code consistently.

The garage said they couldn't reset that fault, but did reset a few others. Some did mention that the sensor for the automatic release (the one that senses if the can is about to roll) needed to be reset, is this possible and is it connected to the switch?

Adp

 

[BlackC55]

What garage. MB dealer/specialist?

 

[ADP]

What garage. MB dealer/specialist?

Specialist

 

[ADP]

You'll see it - it's a rather large sensor sticking out of the side of the ram. That's the replacement part number - though you should test the old one first as a matter of course.

I'm pretty sure I have tested the switch correctly, I used continuity tester. I placed the + and - on the switches terminals and pushed the black spring loaded section towards the terminals this making a curcuit and produced a reading on the meter. Is the switch operated by the roll bar switch on the centre console?
Adp

 

[stats007]

The sensor provides a signal to the ECU to indicate whether the roll bar is lowered - this signal is used by the switch S83 on the centre console as well.

 

[ADP]

The sensor provides a signal to the ECU to indicate whether the roll bar is lowered - this signal is used by the switch S83 on the centre console as well.

Is it worth disconnecting the ecu (is it found in the under the nearside rear seat?) to see if it will reset? I'm a bit confused now I thought it was going to be straight forward after finding out what the diagnostic reading meant.
Do you think I should have the ECU read again?

ADP

 

[television]

No harm in trying that

 

[stats007]

Unfortuantely nothing is straightforward with the roof mechanism. You do need the code clearing. Pull fuse 4 in the boot to cut power to the ECU - I wouldn't go fiddling with it directly.

 

[ADP]

Unfortuantely nothing is straightforward with the roof mechanism. You do need the code clearing. Pull fuse 4 in the boot to cut power to the ECU - I wouldn't go fiddling with it directly.

How can the code be cleared if the the garage couldn't clear it, do mercedes garages have better diagnostic kits than specialist? I've spoken to my uncle and he asked if there is relay anywhere that could have gone thats stopping power?

Adp

 

[stats007]

The relays are in the ECU - you would also have differing fault codes. Have you checked all the fuses etc?

ALL codes can be cleared - your garage obviously isn't equipped properly.

 

[ADP]

The relays are in the ECU - you would also have differing fault codes. Have you checked all the fuses etc?

ALL codes can be cleared - your garage obviously isn't equipped properly.

I've checked all the fuses relating to the roll bar and roof operation, well pretty much every fuse is it worth changing them if they havnt blow. Even the ones on the relays in the boot. May be the code kept re-appearing as you said in a previous quote.

Adp

 

[stats007]

The fuses can corrode but you can check for a voltage across them easily enough.

If that code keeps reappearing them either the sensor is at fault - the wiring to the sensor - or the code is erroneous in which case the ECU needs looking at. Bridge the connector to S83/1 and see if anything happens. You could check the switch S83 in the centre console is also functioning correctly.

Your profile doesn't say where you're based?

 

[ADP]

The fuses can corrode but you can check for a voltage across them easily enough.

If that code keeps reappearing them either the sensor is at fault - the wiring to the sensor - or the code is erroneous in which case the ECU needs looking at. Bridge the connector to S83/1 and see if anything happens. You could check the switch S83 in the centre console is also functioning correctly.

Your profile doesn't say where you're based?

Is the sensor the S83/1 switch or is there a seperate sensor? When I press the centre console roll bar switch there is a clicking sound on both actions up and down. I would assume its sending some signal to the roll bar but i will check it. I will have ago at bridging the connector also. I need to edit my profile it's Worcestershire.

Adp

 

[stats007]

S83/1 is the sensor on the ram.

 

[ADP]

I have tested the wires leading to the S83/1 switch and there is no power/signal going to it. The amp meter reads 0.05 constantly when I push the centre console roll bar switch. I also bridged the contector to the S83/1 and nothing happened in additon to pressing the S83/1 in when contected. But when I press the centre console switch there is definatly a clicking sound behind the drivers side rear seat. I have changed all of the fuses linked to the roll bar, just in case. Anymore ideas

Adp

 

[stats007]

I wouldn't expect the current to change as it's a trigger circuit - the clicking is the relay in the ECU - so power is obviously interrupted between this and the hydraulic pump to operate the ram for the roll bar.

 

[ADP]

I wouldn't expect the current to change as it's a trigger circuit - the clicking is the relay in the ECU - so power is obviously interrupted between this and the hydraulic pump to operate the ram for the roll bar.

Is there anyway I can test if power is get to the ram?

 

[ADP]

I wouldn't expect the current to change as it's a trigger circuit - the clicking is the relay in the ECU - so power is obviously interrupted between this and the hydraulic pump to operate the ram for the roll bar.

I thought the ECU was in the area under the drivers side rear seat? And not behind the seat in the roof compartment.

 

[stats007]

The ECU is under the reat seat - not sure what you mean?

 

[ADP]

The ECU is under the reat seat - not sure what you mean?

I thought the ECU for the roof and roll bar was under the rear child seats on the drivers side (thats what I was told by the garage). On the videos I have seen its under a black plastic cover under the storage compartment (vechicles without the optional child seats) behind the driver. Is this not the ECU then?

Adp