W203 C200k engine management light with 2 codes

[c200kk]

Hi,
Today my engine management light came on so I went to my mechanic and he read the codes and it came up with 2:

P2008-004 M16/6 (throttle valve actuator) Actual value potentiometer 2,Comparative error to actual value potentiometer 2.

P2038-001 G3/1 (O2 sensor down stream TWC), Short circuit to ground [PO137]

And he cleared the codes and they didn't come back straight away.

 

[c200kk]

Hi I need to know what causes this? I'm worried it is going to come up again.

 

[DSM10000]

Can your "mechanic" not tell you what is wrong? If not then find a Mercedes specialist near to you that has the Star computer and get them to diagnose and explain.

Your car does not have a throttle cable , when you press the pedal it moves a potentiometer, this provides an electrical signal and this signal is then used to move the throttle on the intake by a motor and the posiiton of this is governed by annother potentiometer or possibly two on some vehicles, the values need to match It suggests a mismatch here.

Thhe other code suggests that you may have a faulty lamda sesnor, this measures the Oxygen content of yuor exhaust and is used to help the ECU adjust various engine parameters.

I am surprised that your "mechanic" did not explain the meaning of the fault codes.

 

[BlackC55]

can your "mechanic" not tell you what is wrong? If not then find a mercedes specialist near to you that has the star computer and get them to diagnose and explain.

Your car does not have a throttle cable , when you press the pedal it moves a potentiometer, this provides an electrical signal and this signal is then used to move the throttle on the intake by a motor and the posiiton of this is governed by annother potentiometer, the two need to match in value. It suggests a mismatch here.

Thhe other code may suggest that you have a faulty lamda sesnor, this measures the oxygen content of yuor exhaust and is used to help the ecu adjust various engine parameters.

I am surprised that your "mechanic" did not explain the meaning of the fault codes.

+1

 

[ipohjohn]

Thanks for explaining the workings of potentiometers in the motor. I always wonder what activates the throttle

 

[mauno]

check the exhaust manifold edge for crack ,that can cause o2sensor error.
the pedal sensor always double for safety the second is half the resistance/voltage value.stardiag tells you that