Reading Codes - Page 3 - PeachParts Mercedes-Benz Forum

wjm · #31 08-08-2003, 08:58 AM

Jim,

Again, my vehicle has a convenience module as I have one-touch window rolldown and all window rollup on door locking (while holding key). Evidently, though, it is not readable on my car as there is no contact at pin #21. So, that issue is now closed.

As you suggested, I read your article #4 but am still unsure how lambda is read on my vehicle,

I don't believe I have an X11 in my car. I do have a duty cycle capable multimeter. Can I assume that Lambda is read using pins #13 "TNA" and #14 "On-Off Ratio" from the X11/4? If so, which probe goes to which pin?

Once I verify this, I should be able to use the info on your #4 page.

Thanks!

JimF · #32 08-08-2003, 10:30 AM

data 'sheet' on the X11 connector and M0039 Lambda tester. If you have an X11, it should be located near the DI module on the left fender.

Pin 2 (grnd), Pin 3 (O2 sensor) and pin 6 (12V) are the needed signals. So a Fluke w/ d/c should work ok!

wjm · #33 08-08-2003, 11:22 AM

Thanks Jim,

Quote:

Pin 2 (grnd), Pin 3 (O2 sensor) and pin 6 (12V) are the needed signals.

I know this is stupid, but how do you connect a multimeter to 3 pins?

I'm at work now (on a Unix Box) so I can't open the attachment at the moment.

Suppose I dont have an X11.. what then? Can I use the duty cycle multimeter to measure lambda using pins 13 and 14? Is there a 3rd pin need?

JimF · #34 08-08-2003, 11:46 AM

multimeter (MM), connect the MM 'minus' (blk) lead to ground and the 'plus' (red) to pin #3 (O2 sensor) for the X11 connector.

For the X11/4 connector, pin 14 to MM 'plus' and pin 1 to MM 'minus'.

The other pins are there for the Mercedes HHT or the M0039 which needs 12V and Ground to power it.

wjm · #35 08-08-2003, 12:55 PM

OK, I'll test it out today.

So the only question left is ... What is pins #13 "TNA" for and how is it read?

I plan to document all of this info.... although this thread will still be here.

wjm · #36 08-08-2003, 02:06 PM

OK,

Using multimeter with Duty cycle setting, connected black to pin 1 and red to pin 13. Air off and ignition on (engine off). Got 49.9%. THen started engine and tested at idle. Got 49.9% again.

JimF · #37 08-08-2003, 04:15 PM

warm up and you should see an 'oscillating' 50% duty cycle showing the 'lambda' system is active.

Looks good!

wjm · #38 08-08-2003, 05:24 PM

Jim,

Car was at full temp when tests were performed. I had just gotten back from work and kept the engine running while I went in to get my multimeter.... So it was well over 80degC.

Also... FYI...

Quote:

REF.NO.: MBNA 07.4/1, 58/74

DATE: April 1994
TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS
SUBJECT: MODELS 124, 129, 140 WITH ENGINES 119/120 LH-SFI ELIMINATION OF 9-POLE DIAGNOSTIC CONNECTOR (X11) AND TDC SENSOR (L1)

As of July 1993 production, the 9-pole diagnostic connector (X11) and TDC sensor (L1) have been eliminated from the engine compartment on the above-mentioned vehicles.
Note :On engine 120, there is a left and right diagnostic connector and corresponding TDC sensor (X11/2, X11/3, L1/1, L1/2, respectively).
Due to the elimination of the 9-pole diagnostic connector from the engine compartment, an adaptor cable must now be used to replicate this function and supply the needed signals (connectors "A" and "B") from the ignition control modules (N1/3, N1/4, N1/5) and 38-pole data link connector (X11/4) (Figure 1). As a result, an engine analyzer can still be used for diagnostic purposes.

The Lambda output signal has been incorporated in to the 38-pole diagnostic connector (X11/4). The signal can be read using the engine analyzer or the Lambda meter via the adaptor, using socket 14 (engine 119) or sockets 14 and 15 (engine 120) of the 38-pole data link connector (X11/4), (Figure 1) or with the Hand-Held Tester (HHT).

Due to the elimination of the TDC sensor (L1), the ignition angle must be verified with the HHT, or a strobe light can be used if necessary.

Diagnostic test connections are included with the adaptor and are to be followed accordingly.
Note :When using the Bear Dace engine analyzer, 2 adaptor cables will be necessary for diagnosis on engine 120. In addition, it is considered normal if the - 200 icon flashes on the Bear Dace engine analyzer, since this signal is not in the adapter cable socket.

Order No. S-SI-MBNA-07.4/1-58/74

Anyone out there have info on PIN 13?

Thanks

Joseph_H · #39 08-17-2003, 01:46 PM

it works GREAT!

I tested all the modules available for my car in the 38-pin socket and didn't get DTCs (all came back with 1 flash). However when testing pin 30 (SRS module) the LED behaved weird:
Plugged Black in Pin#1, Red in pin#3 for Gnd and power respectively. Yellow in socket pin #30 (SRS) and pressed PB for 2-3 secs LED is ON and released PB. LED stayed on for about 1 sec then went OFF. No status reported... Not sure what that means? Any ideas?

JimF · #40 08-18-2003, 09:53 AM

your car is digital, so need a scanner to properly read the codes in that system.

Good deal on the rest of the car!

Joseph_H · #41 08-18-2003, 11:03 AM

makes perfect sense! Thanks Jim.

wjm · #42 08-18-2003, 11:13 AM

As I said earlier, I did get a code on SRS Pin #30. The code seemed to indicate that the passenger air bag had been unplugged. I had taken it our recently to replace the aspirator motor. Now, after clearing the code, I get a single light blink.

Joseph_H · #43 08-18-2003, 11:34 AM

Quote:

[i]Now, after clearing the code, I get a single light blink. [/B]

Why would you get a status reading from your SRS and I can't? Your E420 is 94 and mine is 95... would that be the reason? I believe JimF mentions in his site the LED box works for up to 94 models (Analog)...

wjm · #44 08-18-2003, 11:41 AM

I really don't think that there is a difference in the computers between the 94 and 95... but I'm no expert. You seem to be getting back some feedback per your earlier message (1 blink), so I don't really see where you have a problem.

Joseph_H · #45 08-18-2003, 11:55 AM

Quote:

You seem to be getting back some feedback per your earlier message (1 blink), so I don't really see where you have a problem.

Willy, maybe I wasn't clear when I described the LED behavior when testing SRS module (pin-30). Normal behavior for the LED to go ON as soon as you press PB for 2-3 seconds to initiate the test. Then it should go OFF when you release PB and then LED will blink with DTC status number. What I experienced is that the LED “stayed” ON after I released PB without any delays and then went OFF.