Posted by Peter Holland on November 3, 2006, 8:40 am
This car came to us a few weeks ago with a throttle pedal position sensor fault with DTC's stored. Scoped sensor and confirmed faulty. Fitted new sensor, cleared codes and all ok. Has now come back with an idle fault, but only when the engine is cold. No DTC's stored, TPP sensor still checks ok. Throttle position varies quite badly, making the car lurch when you select drive. Vary nasty to drive. Scoped TPS - readings consistent through throttle range - TPS 1 reads 4.25V to 400mV at WOT. TPS 2 reads 700mV to 4.6V WOT. Live data shows the throttle being opened by the ECU and TPS voltages react. The only strange part is the simulated TPS switch on live data shows idle going to invalid signal and full throttle with nothing in between. This reading changes as the idle surges up and down. I don't think the throttle body is faulty as both TPS's check ok. Any ideas?