The Chassis Acceleration Sensor (CAS) consists of a piezoelectric vibration pick up which detects vertical acceleration of the vehicle. The sensor signal is used by the ECM to determine the degree of vertical movement of the car, for example, on a bumpy road. Since this may also cause uneven engine running, the ECM uses the signal to distinguish the phenomenon from actual misfiring.
If the value exceeds threshold value, the ECM judges this as a fault and DTC P1307 is set.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Input signal check | ● Contact resistance in connectors ● Open or short in signal circuit ● Open in ground circuit ● Open or short in power circuit ● Faulty CAS ● Faulty ECM |
Enable Conditions | ● No vehicle speed sensor signal > 3sec | |
Threshold Value | ● Measured voltage - modeled vlotage > 0.2V | |
Diagnostic Time | ● 15 sec | |
MIL | ● ON |
Acceleration (G) | -5 | -3 | -1 | 0 | 1 | 3 | 5 |
Output Voltage (V)( Approx. ) | 0.81 | 1.49 | 2.16 | 2.5 | 2.84 | 3.51 | 4.19 |