I decided to take my 96 300D to a German Car Specialist concerning the P0120 Throttle Position Sensor check engine code.

The technician indicated that the problem is that the car needs a Fuel Shutoff Valve (also leaking) and an Accelerator Pedal Sensor. Does this sound correct to resolve a P0120 error? It is extremely expensive to replace both of these parts.

Does my car have an Accelerator Pedal Sensor? I can't seem to find it in any parts catalog? They confirmed that there is no vacuum leak or electrical problem.

Thanks for the guidance.

You can easily test pedal sensor or tps with a scope.
Ask him to show you what YOUR bad sensor waveform looks like compared to a known good.

A good sensor will not have glitches or drop outs in the wave form capture. When actuating it, it should he nice smooth and complete line on the scope.

IMO you cannot properly condemn this kind of sensor without a scope.

Also the shut off valve is $134, there's an O ring behind the shut of valve inside the injection pump that wears out too.

Either way, you're looking at one hell of bill if the tech replaces the shut off valve.

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

Have him replace the tps and the oring referenced above.

__________________
Jim

Hi All,

I picked up my car from a German Car Specialist Shop who replaced the Throttle Position Sensor (used from a 99 300TD) and the TPS (code P0120) problem still occurs.

To summarize, I have replaced on my 96 300D both intake manifold flaps, vacuum pressure transducer, EGR pressure transducer, TPS and checked all vacuum lines and I am still getting the check engine light consistently.

The Tech is puzzled and was confident that TPS failed the test. It seems it could be electrical in nature? Does the TPS need to be reset by adjusting the gas pedal upper and lower limits? Any other thoughts?

Thanks!

Only thing I can suggest is taking a look at the two small electrical connectors to the intake manifold controllers under the intake manifold. When doing some work on my vehicle, I had to remove the intake manifold. When I replaced it and started the car, I had that code come up, and decided take a second look at the underside of the intake manifold, and found that one of the small wires of one of the connectors had broken. Re soldered it back in place, and all was well from that point on.

__________________
96 E300d