The diagnostic port for the top and roll bar has only 4 ports

W124 soft top manual operation 1994 E320 Cabriolet - Page 6 - Benzworld.org - Mercedes-Benz Discussion Forum

Woops, I meant I plugged into 1(ground) and 16(power) in the engine bay and number 2(other color) in the passengers footwell. I have pm'd Arthur and he said you read from port 9 in the engine bay for the roll bar and CST. I got 1 flash from that port, which means no codes.


Also had noticed, somewhere along, someone had replaced the 8AMP fuse (A) in the underhood fusebox with a 16AMP. Something fried somewhere?

I know I read and cleared my codes from the port in the footwell. It will give you both CST and roll bar codes. From your description in this thread it sounds like one your axle switches is bad, you may be able to reset but long term sounds like it needs to be replaced. When you use the port in the footwell the codes flash on the cst switch, do you get any codes when you read from the footwell?

Thanks vexed, I will try again tonight and and look at the CST switch for the blinking codes this time!

Poke around in the following thread:

E320 16 PIN DTC Charts inc. pin 8, pin 14

A link is buried in the thread that contains a pdf file, which shows you how to get the codes (including engine, roll bar, and cabriolet top) for the pre-OBD2 vehicles from that era, including yours. It should answer some of the questions you have.

I used the same pins in the 16(?) pin connector near the battery for power and ground. You only need the "test" lead for the footwell connector.

Good luck.

Will give it another shot tonight, and look at the CST button. Does have know a good source for the rear axle switches?

I am getting no codes no codes from there . I noticed when I press the momentary-switch button on my home-made scanner, my CST button dims until I let go of the button. But no codes are being flashed at all.

At Pin #9, i am getting a code 1 (No diagnostic trouble codes (DTC) stored in memory), even with my rear axle switches out.

In this document, http://www.w124performance.com/docs/mb/diagnostics/DTC_List_W124_M104.pdf. It says

"Pin #9 - Roll Bar (Cabriolet only)
(WIS Group 91.59, subgroup 19.1, section 12, one page) - Only blink codes are available"

and then

"CST / RB (Cabriolet Soft Top / Roll Bar) – Not tested at 16-pin connector – see diagram
(WIS Group 77.39, subgroup 11.1, section 12, two pages) - Only blink codes are available"

From what you posted pin 9 would give roll bar codes. Have you tried disconnecting the roll bar controller. To do this disconnect the battery and then the controller which is underneath the rear seat. It's the hack way of ctrl-alt-delete wait an hour and then reconnect in the reverse order, eg battery last. The thought is that clears any faults stored in the controller.

Tried that with no luck, I can't seem to hear the pump run when I press the button to lower/raise the rollbars. Also when I start the car, the rollbar light doesn't flash at first, it just comes on steady. (Just got car back from bodyshop)

Have you tried to read the codes? If the light is on steady there is a fault somewhere. The light should flash and then go off. Is the rollbar or down. If its down leave it there.

Tried reading the codes but got none, the roll bars are in the up position. Will try the codes again tonight

The top mechanism won't work if the roll bars are in the up position.

Kestas is 100% correct, the soft top switch won't light because the roll bar is up and therefore the top won't move.

Have you pulled the rear seat out and listened to what happens when you try the roll bar switch. There is a another switch in the rear of the center console for the rear passengers. Also the roll bar is not actuated by the hydraulic fluid pump, I believe there are solenoids that raise/lower it.

You should have a code. Are the two switches by the rear axle in the right position?

I have the rear seat out but don't hear anything when trying to lower the roll bars. I tried reading the codes again from port 9 under the hood. I got a code 8 (Roll bar malfunction indicator lamp (E30)), cleared it and I just get 1 flash now which means there's no codes stored. Now the roll bar light comes on when I first start the car then goes off (normal?) but the damn roll bars still won't go down. The buttons to raise/lower the roll bars are always lit?

When trying to pull codes from port 2 under the passenger floor mat, I don't get any flashes at all, not even 1. The red soft top switch is always lit up but doesn't do anything when pressed.