The Vacuum Pump System is set up in a vehicle in order to make the vacuum enough when a drvier presses the brake pedal on the high ground. To operate this system, the vacuum pump is installed on a vehicle.
If the vacuum is not sufficient to press the brake pedal, the HECU senses it through the vacuum switch, which is installed on booster. And then the HECU supplies the power to the vacuum pump by grounding the circuit of the vacuum pump relay. When the vacuum pump is supplied with electric power, it makes the vacuum and supplements it to the booster.
The HECU monitors the vacuum pump system for a normal operation and if it senses that there is a problem in the vacuum pump system, this DTC is set.
Item
Detecting Condition
Possible cause
DTC Strategy
System Monitoring
Poor connection
Faulty vacuum pump
Faulty vacuum switch
Faulty HECU
Enable Conditions
After the consecutive 2 operation cycles, the vacuum switch's signal is "ON"
Fail Safe
-