EVAP canister purge valve (321), E39
EVAP canister purge valve (321), E39 |
Location |
EVAP canister purge valve (321), E39
Main task |
The purge valve controls the amount of air/hydrocarbons which are to be drawn into the engine according to the current operating conditions.
Fuel which evaporates in the tank is led through a pipe to the evap. canister. The active carbon in the canister becomes saturated as it absorbs the hydrocarbon vapours. When the motor starts ambient air is sucked through the carbon filter, via the purge valve and a non-return valve in the intake manifold. The petrol vapours follow with the air and are burnt in the engine.
Type |
Solenoid valve. The evap canister purge valve is closed with no power.
Connection |
321 pin no. | Signal type | Description |
A | Power supply, B+ | Connected to fuse 3 in the petrol engine system fuse box (727), E39. |
B | Control | Connected to ECM pin 51(B). |
The evap canister purge valve is powered from the engine management system main relay (229), E39, via crimp J216, fuse 3 in the petrol engine management system fuse box (727), E39, and crimp J215.
It is operated through pulse width modulation (PWM) to ground in ECM, control module, E39 (590). The operating signal is normally 16 Hz, but with the tank integrity diagnosis it is 8 Hz.