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.
ECM sets DTC P1309 if the ECM detects signal voltage higher than the possible range of a properly operating CAS.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Signal check,High | ● Contact resistance in connectors ● Open or short to battery in signal circuit ● Open in ground circuit ● Faulty CAS ● Faulty ECM |
Enable Conditions | ||
Threshold Value | ● CAS signal > 3.5 V | |
Diagnostic Time | ||
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 |
