AusTex

Hello All - new to the forum -just bought a 2001 E320 with 75k on it.

Drove back from Dallas where I purchased the car with no issues but a day after getting home it threw a CEL (as well as the flashing light by the gas gauge) and code 4055. I trouble shot it tonight with some great help from this forum and hopefully got my purge valve going again (I flipped the gasket over too for good measure, but it looked fine)!


Anyway, I have about a 15% difference between my analog speedo and the digital speedo with the digital being faster. Its difficult to tell if traffic is moving at 70 or 80! I assume the analog is more accurate? Anyone else have this issue? I apologize if this has been covered, but I did a search and didnt come up with anything.

Thanks!

ron m.

I suggest that you borrow a portable GPS to verify. Models like the Garmin Nuvi have mph values that match my car's speedo exactly.

AusTex

Ron - thanks I guess my question is does anyone else experience this? One of them has to be off and if the digital one is indeed incorrect, is there a fix? I assume this is also impacting my odometer?

ohlord

check the digital by going into the climate control diagnostics and looking at the digital speed read out on the climate control panel.
Running stock rims with oe diameter tires?
Find a clear stretch of road with mile markers and calculate which speed is correct.Do it at night with no traffic,set the cruise control for 60 and get out the stop watch for 5 miles. 5 minutes five miles checks the speedos and the odo all in one swell foop
ohlord
"GOT CODES?"

AusTex

ohlord - yes stock rims and tires. Will do the mile marker and GPS to see which if the digital or analog is the most accurate. How do I get into the climate contol diagnostics? I looked thru the owners manual and didnt find anything.

Thanks

ohlord

for a/c diagnostics you only need 1-8 but if you keep going at about 21 or so I can't remember everything you will see a value that corresponds with the mph you are traveling.Might be 21 or 22 or 23 you will know when you see it.You can also at one of those values see the charging output of the alternator at around 13.5-13.7 volts

of course that is not in the manual,they did not get the name stealership by making it easy to discover to fix your own a/c or buy a code scanner for 50 bucks and diagnose your own check engine lights,or reset your own transmission shift characteristics.
If they could not sell $150 mass air sensors installed in ten minutes for $880 poor things might go out of bidness
ohlord