Corsa-B.uk - Vauxhall, Opel and Holden Corsa B Owners Club

I have a fault P0505 which is the idle control valve high / low. I have replaced the idle control valve, throttle position sensor and cleaned the throttle body. None seem to have fixed the fault. When testing the wiring I noticed that I am not getting any signal to the idle control valve. I have checked the connector going into the valve and it is firmly seated but I cannot see where the other end of the cable goes without taking more of the engine apart. Does it plug straight into the ECU? If so is it a connector that may have come loose or is it hard wired in? If it is hard wired in will I need a new ECU?

Many Thanks

Alan

hmm, try pulling the battery off for a bit, then try it, see if the ecu picks it up

icv wireing is straight to the ecu in amongst all the other engine loom.

what engine, and year?

Hello Adam,

Thanks for the reply. It is a Corsa Envoy, not sure of year but I think 1999. I disconnected the battery for half an hour and tried again and the same fault came back but now I am getting a signal to the idle valve. Thanks! I can now rule out a bad connection. If I use a battery to fully close the idle valve and switch the engine on it extends the idle valve to the maximum and then the engine management light comes back on with a fault P0505. Some more info I got from the laptop with the engine management light on:

Idling at 1400 revs
Idle Switch = Closed
Throttle Position Sensor = 1.05V
Throttle Angle = 0
EGR = Inactive

If I press the accelerator the results vary:
Revs increase
Idle Switch = Open
Throttle Position Sensor increases
Throttle Angle increases
EGR alternates between open / closed

I am now wondering if it could be blocked hose somewhere in the throttle body - perhaps not getting enough air? The throttle body appears to be clean and the "butterfly" is clean. Any ideas?

Alan