94 C280, CEL on

[Green Lantern]

hey guys the CEL on the benz just recently came on and i was wondering how can i diagnose it? on my lexus im able to put wires in the ports and count the blinking lights but i dont know if i am able to do it here.

problem: the a/c is currently on the fritz...when we want cold air..it sometimes spits out hot air and the other day we were messing with the a/c controls to see what was wrong and nothing worked. so later on when we started the car...we noticed the CEL was on and the cars RPM was surging from 500-1200 rpm. and when we shut the A/C off it would go off but come back later on. also when we shut the a/c off, there is some whining some coming from the backseats (fuel pump?). Today when i brought the car out, i was sitting outside Rite Aid with the A/C on, all of a sudden all the lights on the cluster came on and rpms dropped to 0 and i had to shut off the car and restart it.

[Green Lantern]

k did a hard reset and looks like its gone..with the CEL. but what is that whining sound in the backseat when the a/c is turned off?

[Green Lantern]

CEL light on...rpms still surging(we are thinking from bad gas since this happened after we filled at a shell station) and i found out where the whining noise is coming from...the passenger side taillight, only comes on when a/c is turned off. how to diagnose the CEL and whats the noise?

[strictlyspeakin]

passenger side tail light area ... the vacuum pump is located near there (inside trunk). Also the fuel pump is back around there too (underneath).

when's the last time the fuel filter was changed?

go to autozone and get them to read the codes with a scanner. then report back what they are.

[Green Lantern]

Originally posted by strictlyspeakin
passenger side tail light area ... the vacuum pump is located near there (inside trunk). Also the fuel pump is back around there too (underneath).

when's the last time the fuel filter was changed?

go to autozone and get them to read the codes with a scanner. then report back what they are.

thinking about changing oil, oil filter and fuel filter at a friends uncles shop on saturday...i went to autozone and they told me it doesnt work on my car....wtf?

[strictlyspeakin]

yes i know. either lie to them and tell them your car is a 97
or talk a confident game and assure them it will. cause it does.


or buy a scanner and plug it in yourself.

:)


did you figure out if the whine in inside the trunk or underneath the car yet?

[Green Lantern]

Originally posted by strictlyspeakin
yes i know. either lie to them and tell them your car is a 97
or talk a confident game and assure them it will. cause it does.


or buy a scanner and plug it in yourself.

:)


did you figure out if the whine in inside the trunk or underneath the car yet?

the sound is right next to the where the passenger taillight bulbs are...alright ill lie to em and tell them its a 96 :D. 94 MBs were obd2?

[Green Lantern]

CEL code fixed..P01010...MAF was messy but hit it a few times with a screwdriver and cleared code and it worked like a charm. also discovered that my minor oil leak has turned into a huge mess.....oil leaked all the way to the cat converter and trying to determine where the leak is now..

[Green Lantern]

CEL back on..guess ima get a new maf....are the ebay ones good? cuz i see the used ones.

[strictlyspeakin]

yup. the 94 was one of the earliest adaptors of obd2. I don't think it has everything the later model do...but it's nice.

by your description, I'd guess that it must be the vaccuum pump. it's the only thing in that area. I've no idea why it would be whining though.

good luck with the oil leak. hope it's not the head gasket.


I think the code you meant was P0101.

can't comment on the ebay MAFs. no experience.

[Green Lantern]

Originally posted by strictlyspeakin
yup. the 94 was one of the earliest adaptors of obd2. I don't think it has everything the later model do...but it's nice.

by your description, I'd guess that it must be the vaccuum pump. it's the only thing in that area. I've no idea why it would be whining though.

good luck with the oil leak. hope it's not the head gasket.


I think the code you meant was P0101.

can't comment on the ebay MAFs. no experience.

theyre saying it might be the timing belt cover..but gonna bring back to check where its leaking.

[Green Lantern]

rear main seal....couple coolant hoses front of sway bar...and some metal looking thing on the driver side of lower engine block.

[junklar]

The whining sound is coming due to a leak in a vacuum line.. I have the same problem and the only way to solve it is to remove the dash completely (or ignore it?)..

a member named zadefaraj has a detailed tutorial on here as to how to remove the dash to fix the whining.. search zadefaraj and it'll come up