My CE light just came on tonight. I did some maintenance on my 1996 E320 last weekend and I am wondering if I did something to cause this. I installed a new battery, oil change, tires and replaced the stock air filter with an aftermarket intake. Obviously the first 3 would not cause a CE activation, but the air intake install...? Any ideas? Thanks.

Well first thing to do is pull the codes. That will get you in the ball park, then you gotta decipher the codes. My code 8 keeps popping up and I have no idea what temperature circuit number one is. I thought I got lucky when I noticed the temp sensor wasn't keyed, but the cable was. I think the cable was put in incorrectly, so I fixed that and then erased all the codes (not just the code 8) but it still turns on,,,

ANYONE KNOW HOW TO FIX A CODE 8 that causes the CEL to light?

<<ANYONE KNOW HOW TO FIX A CODE 8 that causes the CEL to light?>>

What are you yelling for??

You have to ohm test the coolant temp sensor.
My bet is you have a poor connection at the CTS ..also look at the insulation of the harness/connector.............

Sorry not yelling, but rather talking very loudly,,,

If it's not a bad/ohmic connection, use a ohmmeter to check the resistance; it s/b 310 ohms at 100C. If it's 5 - 10% higher (normal aging/failure of a varistor causes it to read higher resistance), then replace it.

Code readings off the charts!
 

Well first thing to do is pull the codes. That will get you in the ball park, then you gotta decipher the codes.

Ok, check this out. I am not going to attempt to make a homemade code reader or whatever so I take the car to my mechanic and his diagnostic computer just locked up and would not give a reading at all.

He had to take the car to another shop and their machine worked, but it came back with 25 codes! :eek: It's like a friggin' bingo scorecard.

P0116, P0170, P0101, B1100, B1234, B1419, B1422, B1424, B1220, B1221, B1010, B1000, B1203, B1012, B1014, B1021, B1124, B1438, B1436, B1214, B1119, B1200, B1470, B1231 and B1232.

Now either my car is dead and doesn't know it or one of my computers is messed up. Anyway, I took my friends advice (confirmed by the Mercedes dealer believe it or not!) and simply unplugged my battery and replaced the OG air cleaner system and wala-no more CEL and no need to buy a $300 mass air flow sensor or anything else-for now.

This lead me to think about a few other things. When I bought this car in Japan I had to change out the instrument cluster (km to mph) in order to conform to CA DOT; could that have caused some electronic gremlins in the car? And, I am also wondering if these Mercedes systems are so sensitive that DIY maintenance is just not possible without having to "reset" the electronic brains that control the whole car everytime you change a sparkplug!?

Any advice out there to a newbie owner who likes to work on his cars, but is scared to mess with this one anymore. Cheers. Hiroshi.

Check Engine Light
 

My Check Engine light came and it threw the code for a faulty Upshift Delay Valve. Does anyone have a step by step procedure in replacing this valve. I know it entails pulling the pan off of the transmission to access the valve but I really want a step by step so I don't mess it up.

Mine developed the same problem recently. Usually it's the valve itself that goes. First verify by applying vacuum to the unit via the vacuum line behind the brake booster. If it holds vacuum then the valve is good and the problem may be the solenoid relay. The valve is $200, the solenoid is $35.

I just put a small ball bearing in the vacuum line anad live with it. The problem is that I have to clear the check engine light every now and then.

Holding a vac does not verify the delay actuating element or cable
mechanism as good. It simply means it does not leak...it does not mean it works.
The test is to couple the input/output lines at the Switch Over Valve [ not a solinoid relay]...then drive the car to see if the cable fulcrum holds the trans in delay gear. That test eliminates the electronic diagnosis b/c you are manually using the actuating mechanism via direct engine vac supply.

And if the BB trick is used , one only has to use the lower shift range when cold/first start to eliminate the CE lamp b/c it will not be called for by the ECU parameters b/c the rpm signal to set the 26 code fault will not be met.