Hi All,

I pulled the code 2 from pin 7 and code 8 from pin 4 from the X11/4 connector using K6JRF's Page as a reference; however, I'm not sure if they're applicable to a 1994 C280.

[Fault Table, DTC Readout, LH-SFI Module (N3/1)]
DTC#8 - "CMP sensor (L5/1), open/short circuit"


Fault Table, DTC Readout, EA/CC/ISC Module (N4/1)
DTC#2 - "EA/CC/ISC control module (N4/1)"

The codes were pulled due to an OBDII "P0505: Idle System Malfunction" resulting from a Check Engine light.

Can someone please help in troubleshooting the above codes and what the possible causes are. I'm at a loss as this is the first time I'm working on this car.

Thanks to all,

__________________
sjsfiji

'87 W124 260E (DD)
98K orig. mi. @7/15
CLK 7-Spoke Forged Wheels
Neuspeed springs/Bilstein Sport
4/3 bump (F/R)

'97 993 Carrera
106K orig. mi.
Always driven like it's stolen

Wrong code list - for 104 / 202 Pin 4, code #8 is "Idle speed control (ISC) system at upper or lower control stop or CC or EA indicates "limp home" mode". If you're not in the limp home mode, and you'd probably know if you were, it must be the first one. Assuming you don't have ASR Pin 7, code #2 is "cruise control / idle speed control module". These two plus the PO505 looks like the trifecta, perhaps engine actuator. But what are the operating symptoms?

Thanks for the reply. Here are the symptoms...

Start - fluctuates for 1 cycle - it goes to 1200, drops to 400, then stabilizes to 600... I drive 'til operating temp (greater than 80 deg C), stop then place in 'P'. Idle stays at 1200RPM... I drive again and place in 'P'. It just stays at 1200RPM...

I'll have to check if I have ASR...

thanks a mill. for helping...

__________________
sjsfiji

'87 W124 260E (DD)
98K orig. mi. @7/15
CLK 7-Spoke Forged Wheels
Neuspeed springs/Bilstein Sport
4/3 bump (F/R)

'97 993 Carrera
106K orig. mi.
Always driven like it's stolen

As long as it's working clear the codes, keep driving it and see what comes back. Codes might come back before CE light comes back on. Symptoms sound a little like bad air mass sensor.

Thanks for the reply... the same codes (pin 7 code 2 and pin 4 code 8) have come up after clearing both codes and the "check Engine Light", then driving the car for 20 miles. The CEL has not returned as of yet.

What do you suggest I do? Should I replace the 'air mass sensor' and see if it fixes the problem? Is there a way to diagnose the sensor with a multimeter or something?

Would the same codes come up with a bad 'air mass sensor'?

Thanks for all the help...

__________________
sjsfiji

'87 W124 260E (DD)
98K orig. mi. @7/15
CLK 7-Spoke Forged Wheels
Neuspeed springs/Bilstein Sport
4/3 bump (F/R)

'97 993 Carrera
106K orig. mi.
Always driven like it's stolen

Hi All,

I've been searching the web and others advice that it could be the MAS / MAF "air mass sensor / meter" or the OVP... Anyone else have opinions on this...

Thanks,

__________________
sjsfiji

'87 W124 260E (DD)
98K orig. mi. @7/15
CLK 7-Spoke Forged Wheels
Neuspeed springs/Bilstein Sport
4/3 bump (F/R)

'97 993 Carrera
106K orig. mi.
Always driven like it's stolen

I would try cleaning the engine actuator first - it's cheap. You also can clean your air mass sensor with electrical contact cleaner. Try a search on both. Did you decide if you have ASR? There would be a warning light under the instruments.

Thanks deanyel... I'll try those this weekend... My car does not have ASR... Please let me know how or if this will make it easier to diagnose...

thanks,

__________________
sjsfiji

'87 W124 260E (DD)
98K orig. mi. @7/15
CLK 7-Spoke Forged Wheels
Neuspeed springs/Bilstein Sport
4/3 bump (F/R)

'97 993 Carrera
106K orig. mi.
Always driven like it's stolen

The fault codes lists on PIN 7 are different for ASR versus w/o ASR. I gave you the fault code for without ASR.