Hello, I recently replaced the throttle body in my 2002 XK8. After I put the new one in, I made sure the throttle position sensor (also new) was in the same position as the old one and I disconnected my battery to reset the system. However, I now have messages on my dash saying ASC Fault, ABS Fault, and Failsafe Engine Mode. I have scanned it and found these codes: P1224 (Electronic Throttle Control Position Error) and P0122 (Throttle Position Sensor A Circuit Low Input). Occasionally when I start the car, there will be no messages on the dash but the rpms will rev very high. Any information is welcome.

Thanks.

 

Can you put the original TPS back and see if that makes any difference?

Do the butterfly positions roughly correspond with the % throttle opening as read from your OBD scanner?

Richard

 

[QUOTE=RichardS;2779762]Can you put the original TPS back and see if that makes any difference?

Do the butterfly positions roughly correspond with the % throttle opening as read from your OBD scanner?

I can put the old one back in tomorrow morning and see if there is any difference. As for the butterfly position, I am not certain my scan tool can read that. If it can, I will check it before and after I put the old sensor back in

 

I have a 2000 XK8, aj27 so we have the same TB. I had mine rebuilt and installed with no issues. I don't understand why you wanted the throttle position sensor in the same position as the old one? Perhaps the cable to the TB is to tight and the TB is never in a full idle position? There should be some slack in that cable.

 

[QUOTE=David Dougherty;2779827]I have a 2000 XK8, aj27 so we have the same TB. I had mine rebuilt and installed with no issues. I don't understand why you wanted the throttle position sensor in the same position as the old one? Perhaps the cable to the TB is to tight and the TB is never in a full idle position? There should be some slack in that cable.

I've just read that the tps needs to be in the same position. The cable may be a little tight, but when it revs up when I start it, it's like I put the pedal to the floor

 

I readjusted the new tps and and it seemed to be fine, so I went on a test drive and went over a speed bump and the car shut off and would not turn over until after a few minutes of sitting. The tps connector is still tight
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You have to re- boot after messing with the throttle body…remove battery cable and tape together for 15 min. Then reconnect battery. Next turn ign. On and let system scan run. Then start. All should be corrected. You will need to re-set windows and radio. This cured all my problems with mine.

 

I did the hard reset and it cleared up everything except for the high idle. The code is p0507, engine idle speed higher than expected. I may try adjusting the idle speed sometime tonight it tomorrow

 

Maybe check for an air leak.