MountainStone

Came out of Target yesterday (I'm baller) and started the car. Car tells me 'ESP not available, visit workshop.' Tried to drive and the car had no throttle response at all; it would idle in gear with a top speed of 10mph but would not respond to throttle input. Shut it off and restarted twice with no change. Only two miles from home on back roads so I just turned on the hazards and idled home.

Got home and read the code: P0120

Searched the forum for a couple hours and noticed several instances of similar symptoms being 'cured' by fiddling with the throttle body electrical connector.

I disconnected mine to inspect. Terminal pins and female connector were quite shiny with no apparent overheating or corrosion. Car is bone stock and I don't think that connector has been touched since it was originally connected. I had my doubts but I reconnected it and the car started fine, with no error messages and it responded to throttle input.

Today car started normally and drove around neighborhood normally and to the auto parts store and back normally. Bought contact cleaner and dielectric grease at the parts store and upon return, disconnected the TB connector and blasted each side with the contact cleaner. Greased both sides and reconnected. Wasted two zip-ties trying to strap the connector to the TB before deciding it wasn't gonna work out for me, so I have no zip-tie though the connector retaining ears both snapped on with a satisfying 'click.'

Several test runs later and car is performing normally.

I don't feel like I fixed anything so I'm still wary of this fault recurring. Has anyone discovered why this fault is so (relatively) common? Does this 'fix' last or should I plan to replace the female connector?

betrezra

Fairly common recently w/c55 and clk55's around this board including me.

Option 1.0 - verify TB conn is snapped in tight.
Option 2.0 - clean contacts in conn w/ CLR.
Option 3.0 - could be pedal accelerator sensor (easy to replace).
Option 4.0 - some have had no luck with 1-3 above... and found it was the little tiny female connectors in the TB connector pack..... they get weak after time and give int shorts....... the fix is to get replacement female connectors terminals from dealer, and carefully replace them in the TB connector pack..... then solder the wires into the loop.

I had sim symptoms: no accel.... shut car off, restart.... then ok..... then one random day same thing.....

I ran STAR....... showed TB actuator inop. Ran all the STAR TB actuator tests and showed fine.

So I cleaned the TB connector and it was good for a month.... then randomly faulted.

So I bought a spare TB and ported the blade shaft. Since I bought the spare TB.... car has run fine. When it acts up again, I'll throw on the ported TB and put in the new connectors.

Lenin

Always try the ECU reset first. It's free. Then Option 1-4.

MountainStone

Thanks for the input, gentlemen. I was hoping to hear from a few more folks who've suffered the same failure; I'd like to know whether cleaning and greasing the contacts on the connector is a long-term fix. As it is, I don't fully trust the car.

betrezra

I cleaned my contacts and then had a repeat problem 1 mo later. Then no issues for another month...... so maybe I'm due for trouble?

GL.