I've been studying the functional diagrams and wiring schematics for the CIE-E and EZL systems and can't find a function for the TDC sensor.

The signal lines go to pins 7 and 8 on the X11 diagnostic socket (and pin 9 is the cable shield), and they appear to terminate there, which indicates that the TDC sensor serves no operational function. It's not even clear to me what diagnostic function it serves other than RPM, but an RPM signal is available from the EZL system on X11 pin one.

Am I missing something?

Duke

Duke:

I found a comment made by MBDoc in the following thread that may be of interest.

Part # needed for TDC reference sensor

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

"That sensor is ONLY for info to the factory scope(when connected). HAS nothing to do with the running of the car."
-M.B.DOC

Well, that jibes with my review of the circuit diagrams! My guess is that it allows the OEM test equipment to read ignition advance directly without using a timing light.

Thanks for the link, Mike.

Duke