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RIP, Lead Technician
Category: Car
Satisfied Customers: 5591
Experience:  A.S.E. Master Technician, Advanced Level, Smog - European, Domestic, & Asian -- Car Category Mentor
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Code reader..P0120 TPS/Pedal Position Sensor A Ciruit Malfunction

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I have a 1997 E300D. I keep gettinga message"Check Engine Electronics". I have a code reader and it says P0120 TPS/Pedal Position Sensor A Ciruit Malfunction. When the message comes on the running of the car is not affected at all it runs fine. Also it only occurs when crusing between 65 and 72 miles per hour. Do you have any suggestions as to what is occuring since the vehicle runs fine?

Hi, welcome to jA.

  • How many miles are on this Mercedes?


Customer: replied 9 years ago.
Reply to RIP's Post: I purchased the vehicle used in February this year, so I have no idea what service work had been done to it previously. THe vehicle has 155,327 miles showing on the odmeter. It had 136,000 showing when I got it. the problem started at around 138,000 miles. I was on a trip yesterday approaximately 385 miles and I erased the dtc code 8 times. before yesterday I had driven the vehicle around 2,000 miles with out the error appearing.

Thanks, XXXXX XXXXX this a 300D or a 300E?


Customer: replied 9 years ago.
Reply to RIP's Post: Its an 1997 E300 diesel

Thanks, XXXXX XXXXX Diesel model the P0120 code is not for the throtle position or the accelerator pedal pertains to the Pressure Control Flap Transducer...see the definitions below...


Below is an illustration of the EGR system transducers...most likely one of them is faulty or the vacuum hoses to them...but this system can ONLY be correctly diagnosed with a Mercedes level scan tool.


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