No response from Throttle Pedal.

Ignition 'on' and Throttle Pedal depressed, Throttle Butterfly only moves about 20 percent.

With scan tool Throttle Butterfly will fully open.

Noted: When Scan Tool used, Butterfly was very notchy and didn't always fully open and other small faults found on TPS Circuits.

Advised customer to replace Throttle Body.

New Throttle Body now opens and closes correctly.

Throttle Butterfly now opens to 40 percent and stops.

Accelerator Pedal checked.

Pedal has has 6 wires. 2 wires, 5 volt supply from ECU and 2 ground wires, and 2 signal wires back to ECU.

Voltages at Pedal were:

Track one, at rest, 1 volt. Pedal fully depressed, 4 volts.

Track two, 0.50 volts, Pedal depressed 2 volts.


2 Signal Wires back to ECU were checked for continuity and resistance checks and found to be correct. And resistance check was 1 ohm.

Both signal wires were checked at ECU and found to have same voltages as at Pedal Assembly.

Voltage readings at Pedal Assembly were same as Vauxhall Spec.

At this point I cannot condemn ECU, because scan tool will open and close Throttle Body Butterfly BUT when Pedal depressed Butterfly will only open 40 percent as shown on scan tool.

Wiring from ECU to Throttle Body, must be correct as scan tool will open and close Throttle Butterfly.

Initially, I thought Pedal voltages were incorrect and was going to fit new Pedal Assembly, and so was most surprised Vauxhall data showed voltages were in fact, correct. (Can anybody just confirm that my data for the Accelerator Pedal voltages are correct?)>

What am I missing!

Edited to add: My 'fix post' reflects the first opportunity to post feedback, rather than the length of time the car took to repair!