Component Location
General Description
ECM is activated by power supply. Signals from several sensors, such as CKPS and APS, is inputted to ECM. Comparing inputted signals with control LOGIC saved at micro controller and EEPROM, ECM controls engine as actuating injectors, solenoids and relays. To guarantee accurate control, ECM performs SELF TEST, DIAGNOSIS of several sensors and actuators. And if serious trouble which affects vehicle performance occurs, ECM sets DTCs. At certain cases, ECM shuts down whole systems in order to prevent dangerous situation due to incorrect control.
DTC Description
P0643 is set when the voltage above 5158mV - maximum voltage of sensor power supply 1 generates from ECM - is detected for more than 0.1 sec. This code is due to the short to battery in sensor power circuit or the voltage problem inside of ECM.
DTC Detecting Condition
Item | Detecting Condition | Possible Cause |
DTC Strategy | Voltage monitoring
| Sensor 1 (VSA, EGR, ACV, CRUISE, APS2) power supply circuit
ECM component
|
Enable Conditions | IG key ON
|
Threshold Value | When the voltage is above the maximum voltage (5158mV ) of sensor power supply.
|
Diagnostic Time | 0.1 sec.
|
Fail Safe | Fuel cut | NO | Limp home mode is activated. (Engine speed is fixed at approx. 1200RPM )
|
EGR Off | NO |
Fuel Limit | YES |
MIL | OFF |
Specifications
Sensor power supply | 4830mV ~ 5158mV |
Diagnostic Circuit Diagram