Having some issues with my climate control. Did the standard diagnostic test with the unit and it doesn't throw any codes.

Did the sensor readings and temps/electrical readings are normal BUT have an issue with the ambient (outside) temp reading. When driving normally above 40mph the reading pretty much matches the gauge cluster temp. When sitting after car has been driving the reading is WAY high - 145 and even during a short idle the temp will shoot up from normal. This is a problem because the climate control seems to think its really hot outside and will switch on the ac and blow cold air into the cabin. The interior temp reading shows about 78/79 when the climate control is set at 74 or 75 and will never drop unless you really lower the temp. Seems like its callibrated a few degrees greater than the unit.

Took the car into the dealer and they seem very confused. Gave him my readings. They think by ordering a new climate control unit will solve the problem.

QUESTION: Is the ambient temp gauge reading correctly - or should it pick up the heat from the engine compartment? Where is it located so I can check it myself to see if its plugged in correctly or fitted to the appropriate inlet?

Ambient temp sensor is mounted to the front bumper on the drivers side.

The A/C/C control gets that info thru can bus from inst cluster.

FOR the $$$ involved I would start with a new sensor & check the coding of the A/C/C controller.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Ok, thanks. Thought there were two sensors - one for the outside temperature and another that reads air coming into the airbox. Since the gauge cluster reads true 100% of the time and the climate control module when in sensor mode reads only true when driving at speeds and way high at idle my thinking was that another sensor may have been loose and was reading engine bay temps.

Is is possible to check the coding from the climate control unit without a scan tool.
Have read all the codes and I was able to get into a mode that displays P1 and P2 that allows the user to change values.

Seems like my MB dealer has put someone really inexperienced on the job - know I have an extended bumper to bumper and seems like they just want to throw parts at the problem. Don't want to "soak" the extended warranty company just in case I have a major repair that they may think twice about.

Any help would be appreciated. My last two values which are within the P1 and P2 mode are 200 and 15 if that helps.

Yes the P1 & P2 codes are what I was refering to.

Is the car a coupe OR convertible?

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

2000 Coupe - with Bose, heated seats and rear sunshade - no Xenons/Nav

Tried a few numbers - maybe you can verify if they are correct:

Plugged in 160 for the P1 and 8 for the P2 -

P1 and P2 from the library's Alldata - 128+32 for K1 (don't know what K1 means)

P2 = 8

Didn't really change anything - interior temps still high - set at 73 - reads 78/79