Against my better judgment I have inherited this job from elsewhere, the people in question have been trying to fix it for the last 12 months, The problem being is that the coolant warning lamp is permanantly lit and the vehicle runs like a sack of crap, is difficult to start and will not idle, It is also running rich.
The following codes are displayed: P0118, coolant sensor circuit, P0485, cooling fan status, P1608, output signal coolant temp, P0480, cooling fan relay 1 circuit, P0115, coolant temp circuit.
The customer has bought and fitted a new engine ecu to no avail.
I have done the following: Replaced all of the system earths, removed and cleaned the large plugs and sockets from the under bonnet fuse box [badly corroded], removed and cleaned the socket from the ignition control module [the brown oblong box from next to the main ecu] and refitted the original ecu. sometimes after the ignition is switched off and the engine restated the coolant warning light is extinguished but it still runs badly. Looking at the data while the engine is running the temperature increases and the throttle position sensor shows .59 volts closed to 4.00 volts wide open regardless of whether the coolant warning light is on or off. I have also checked the continuity of the wires from the ect sensor back to the ecu and fitted a new ect sensor. does anyone have any suggestions on what to try next? Thanks, Neil.
Forgot to say the cooling fan relays are in the engine bay fuse box behind the battery and I have tested them and all function correctly.