The latest update:

Prior to driving the Mercedes this morning, I did a DM (16 pin diagnostic module) self test. Code 6 shows up. Code 6 refers to Idle speed control faulty. That is the only code showing using the DM.

Did a code reader scan on pin 6, shows code 9, SRS malfunction indicator lamp (A1e15) or time limit for DTC readout /erasing.


Code reader scan on pin 8, one blink meaning no codes.

Code reader scan on pin 10, one blink meanng no codes.

Code reader scan on pin 14, code 2 meaning EA/CC/ISC control module (N4/1) or Safety contact switch (M16/1s1) or Stop lamp switch or Cruise control switch or Actual value potentiometer or Starter lock-out/back-up lamp switch or engine speed signal or vehicle speed signal or closed throttle position switch or safety relay in EA/CC/ISC control module.


Start up the motor and rmp shows high idling around 15000. Normal idling rpm should be around between 7000 rpm and 8000 rpm, even the same rpm when pressing the brake . Oil pressure reading between 2 and 3. On the warning lights in the instrument cluster panel shows oil sending unit on. That darn smoke (no blue smoke, just close to clear color type) out behind the engine is still there. No smoke coming out the exhaust tail pipe. Press the brake and put in drive and rpm hovering around 10000 rmp. While shifting from Park to Drive, there is a hesitation between shifts. The same results applied to reverse shift as well. Took a test drive of 25 miles or so. I put on the cruise control and it works!! Smooth driving so far, but I also smell burning smoke coming through inside the car with windows rolled up. Tried the heater on and works normally as well as the air conditioning unit. OIl pressure while drivng stayed on above 3 needle mark. Warning light on the oil sending unit stayed on, went away for awhile and came back on again. When pressing the brake to stop while driving on the road, Oil pressure hovering around between 2 and 3.

When I got home, I checked for leaking oil on the engine area and no signs of leaking oil that I can detect of. Also, I checked the oil level on the dipstick and it is fine. I did another dm test and code 6 shows up again. Testing with the code reader on pin 6, no codes. Pin 7, no codes, Pin 8, no codes, Pin 10, no codes, Pin 14, NO CODES!! YEAH, ALRIGHT!! It seems that the throttle body or EA is actually working, (after got it repaired) especially the cruise control unit, but still that darn high idling still persisted as indicated on the Diagnostic Module Self Test code 6, even though there is no codes showing on Pin 14.

Also, clear color smoke was still there along with smelling of burning oil and I was abled to pinpoint the location of the smoke area. It was on the exhaust side near the rear of the engine. There is a pipe or tubing connecting to the EGR valve. I am not sure of the exact spot of the smoke. After turning off the engine and finishing the codes test, I fired up the engine again and this time no smoke or no smell of burning oil. I will continue to monitor the smoke and the burning oil smell.

The only thing left to for me to do at this point is to find out why and fix the high idling even though the repaired throttle body or EA apparently is good, since the cruise control works and no codes showed up on Pin 14. However, on the Diagnostic Module self test shows code 6, meaning Idle speed control faulty. That does not make any sense to me. Could it be the control module (computer) behind the battery is faulty? Loose wiring somewhere? Could the high idling and the shift hesitation in drive and reverse be related? Will have to investigate and research on this and I am hoping that the Throttle body or EA is not the problem. If it turns out that the throttle body is the problem, then I am going to send the EA back to the repair shop that did the work/repaired on the throttle body. The throttle body or EA has a 3 year warranty. In addition. the light up oil sending unit needs to be fix as well. Any feedback/comments on these two issues is greatly appreciated.