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2002 E55 --- stock with Kenwood SatNav and Hertz Energy sound
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17 Posts
Discussion Starter #1
looking for a little help…my 2002 E55 runs very well, with two exceptions:
1. the A/C get fussy after 2 hours if on auto (I think maybe it ices?), but runs better if I leave on 24 degrees/manual
2. the car stops at lights, very quietly, and has absolutely no problem restarting. The other forms indicated a faulty CPS as a possibility but there are no other running difficulties, rough idling, or such.
For info, it has about 300k/180m and is generally well maintained. no faults show on my reader, but it hasn't been hooked up to the fancy MB connector, just OBD2
thanks for any help, sorry if I missed a duplicate thread, I did look. The sudden stops are more concerning, the 24 degrees I can live with.
Mike

:bowdown:
 

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1999 E55, 2001 E320, 1990 560 SEC, 2004 ML350, 2001 ML55, 1995 S500, 1998 SL500, 2010 E550 Sport zoo
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7,035 Posts
2) if the symptom you are describing is a sudden cut off - like a switch turned off your engine - then yes you need a genuine Bosch CPS replacement - again, genuine Bosch - there are 1-tab or 2-tab types depending on connector - as a 2002 yours is most likely 1-tab but best to check by pulling the connector to recheck

1) When you say "iffy" please be more descriptive or best to pull climate control diagnostic when you are "iffy" - most would prescribe a evac and refill to make sure system has correct/fresh refrigerant and evac tests for leaks - but best to do diagnostic first when iffy

Keep the beat !
 

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Premium Member
2002 E55 --- stock with Kenwood SatNav and Hertz Energy sound
Joined
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17 Posts
Discussion Starter #3
2) if the symptom you are describing is a sudden cut off - like a switch turned off your engine - then yes you need a genuine Bosch CPS replacement - again, genuine Bosch - there are 1-tab or 2-tab types depending on connector - as a 2002 yours is most likely 1-tab but best to check by pulling the connector to recheck

1) When you say "iffy" please be more descriptive or best to pull climate control diagnostic when you are "iffy" - most would prescribe a evac and refill to make sure system has correct/fresh refrigerant and evac tests for leaks - but best to do diagnostic first when iffy

Keep the beat !
thanks for the reply, it helps a lot. after an extended period, the A/C seems to continue to blow cold, but air volume from the vents drops off to a very low volume regardless of fan speed. oddly, you can still hear the fan, it just seems to have a significantly reduced output. the blower motor and resistor have been replaced and are the new style, about 3 years ago
 

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Registered
1999 E55, 2001 E320, 1990 560 SEC, 2004 ML350, 2001 ML55, 1995 S500, 1998 SL500, 2010 E550 Sport zoo
Joined
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7,035 Posts
Again, if you have the digital climate control please pull climate control readings when it is "iffy" - yes could be bad resistor, when it heats up loses effectiveness - can be bad mounted of the new resistor as well - noted you believe you have "new/upgraded style" blower and new/updated style resistor.

Keep the beat !
 

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Premium Member
2002 E55 --- stock with Kenwood SatNav and Hertz Energy sound
Joined
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17 Posts
Discussion Starter #5
Thank you for the help, the cps change cleared up the engine issues…..
On the AC side it when I checked the fault codes, B1-416 (engine coolant pump) and B1-234 (AC sunlight sensor) came up. I cleared the codes and will try again.
The water pump was replaced a couple of years ago with a new fan and there is no wobble in the fan visually. I'm not sure what the sunlight sensor is.
I did the operational diagnostic on the AC control unit after driving for a couple of hours and the A/C "iffy" as well, the number 7 stop for refrigerant pressure indicated a 10. I'll run it again today while it's working to compare the numbers.
thanks again for the help. __Mike
 
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