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 P1308 if the ECM detects signal voltage lower than the possible range of a properly operation CAS.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Signal check, Low | ● Contact resistance in connectors ● Open or short to ground in power circuit ● Short to ground in signal circuit ● Faulty CAS ● Faulty ECM |
Enable Conditions | ||
Threshold Value | ● Filtered acceleration sensor signal < 1.5 V | |
Diagnostic Time | ||
MIL ON Condition | ● 3 Driving Cycles |
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 |
