Central mounting box
The central junction box is used to initiate power on and off programs in the ECM. (engine control unit). When the ignition is turned on, the ignition switch status sensor input (contact 30 of connector C0635) 12V voltage is applied. Then the ECM (engine control unit) starts power up routines and turns on the ECM power relay (engine control unit).
After turning off the ignition (oFF position) ECM (engine control unit) maintains power for several seconds (in extreme cases, if necessary for the cooling system fans, this can continue for 20 minutes), performing the shutdown procedure, and then turns off the ECM power relay (engine control unit).
Power supply
For the operation of the ECM unit (engine control unit) requires a continuous supply of battery supply voltage as well as a commanded supply of battery supply voltage. The commanded supply voltage is supplied through a relay controlled by the ECM (engine control unit), based on the state at the input of the central switching unit (key position 2).
In the "OFF" position of the ECM key (engine control unit) keeps the supply voltage on until the internal self-diagnosis is completed. The main supply fuse is located in the engine compartment fuse box.
Purge valve
Hoses and purge valve
| Item name | Spare part catalog number | Description |
| 1 | - | Electronic throttle |
| 2 | - | Air intake manifold |
| 3 | - | Fuel supply pipe |
| 4 | - | Blow-off hose nipple |
| 5 | - | Purge valve |
| 6 | - | Blow off valve bracket |
| 7 | - | Hose clamp |
| 8 | - | Hose connecting the manifold to the purge valve |
To meet increasingly stringent fuel vapor regulations, the vehicle uses a fuel vapor recovery system that minimizes losses from the evaporation of fuel vapor from the fuel system into the atmosphere. This is achieved by removing gases from the fuel system through a vapor trap. (carbon adsorber)The carbon acts as a sponge and traps the vapors until the canister is purged under the control of the ECM. (engine control unit).
The carbon canister is connected to the intake manifold behind the throttle body via a purge valve. The state of this valve changes according to the PWM. (pulse width modulation) - signal transmitted by the ECM unit (engine control unit). The adsorber is purged by pumping clean air through the carbon, which carries the hydrocarbons into the engine, where they are burned. To maintain controllability and reduce exhaust toxicity, the purging process must be fully controlled, since even 1% of fuel vapor from the adsorber entering the air intake can lead to a 20% change in the composition of the working mixture. Since the accumulation capacity of the carbon is limited, purging to restore its condition must be performed regularly, alternating with fuel supply correction, since both operations cannot be performed simultaneously.
ECM (engine control unit) via PWM (pulse width modulation) - the signal controls the purge valve, regulating the intensity of the purge of the adsorber. Control of the purge process allows maintaining the stoichiometric composition of the working mixture necessary for the correct operation of the engine. In addition, due to this, the purge of the adsorber is performed quite often, thereby preventing the saturation of the coal with fuel, leading to excessive accumulation of fuel vapors in the system (and therefore to an increase in vapor pressure) and, as a result, to an increased likelihood of vapor leakage. For more information, refer to Evaporative Emissions (303-13A)
Comments on this article