SsangYong: Engine Euro 4. Manual - part 27
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN
33
2411
EXHAUST SYSTEM
D27DTP/D27DT (EU4) SM - 2006.08
D27DTP/D27DT (EU4)
ENGINE
FUEL
I
N
T
AKE
EXHAUST
PRE-HEA
TING
LUB
COOLING
SWITCHABLE
ECU
DIAGNOSIS
Throttle Body and Throttle Flap Actuator
For the vehicle equipped with CDPF, the throttle body is installed in the opening of intake manifold. The flap in the throttle
body is actuated by vacuum and the throttle body is operated only when the engine is idling (700 ~ 800 rpm) or running
at below 2500 rpm without accelerator pedal depressed. (For detailed operating range, refer to the control map.)
With EGR ratio and pressure difference provided by the differential pressure sensor, the ECU determines the CDPF’s
burning range. If the ECU determines to burn the soot in CDPF, it checks whether the engine is running in low load
range (engine idleing or running at below 2500 rpm without depressing the accelerator pedal). If the engine is running
in low load range, the flap in the throttle body is closed by vacuum modulator. The flap is not completely closed to
prevent engine from turning off.
In summary, the operating conditions for the flap in the throttle body are as follows:
Overview
Actuator for controllling
throttle flap
1. When the CDPF’s burning conditions are met (soot mass is over the limit and EGR ratio and tempera-
ture of exhaust gas are met with operating conditions)
2. When the engine is running in low load range (idling (700 ~ 800 rpm) or running at below 2500 rpm
without accelerator pedal depressed)
It controls the flap in the throttle body.
Vacuum actuated:
Throttle flap closed
→ Vacuum pressure at approx. 680
~ 720 hpa (intake air volume decreased)
Vacuum released (atmospheric pressure actuated):
Throttle flap opened
→ Atmospheric pressure actuated
(normal amount of intake air supplied)
Vacuum Modulator for Controlling Throttle Flap
Throttle body and throttle flap actuator
• The flap in the throttle body is operated only when the engine is running in low load range. It is to
increase the temperature of exhaust gas by decreasing the amount of intake air and increasing the
amount of fuel supplied since the fuel including post injected fuel is not enough to increase the tem-
perature up to the CDPF's burning temperature.
NOTICE