DTC Advanced Diagnostics: P034A (3.0L Engine)
DTC P034A: Crankshaft Position (CKP) Sensor Start Position Incorrect
General Description
The crankshaft position (CKP) sensor consists of a rotor and a semiconductor that detects rotor position. When the engine starts, the rotor turns and the magnetic flux in the semiconductor device changes. The changes of magnetic flux are converted into pulsing signals to the powertrain control module (PCM). The CKP sensor detects injection/ignition timing for each cylinder and engine speed. At the timing of engine is restarted from auto idle stop, the PCM determines a backward of the crankshaft. The crankshaft pulse becomes other than the expected amount when the crankshaft rotates backward due to engine vibration, etc. However, the PCM cannot conclude if it is a backward rotation only with this factor. If the crankshaft pulse is other than expected amount when the engine is restarted from auto idle stop, but the PCM cannot determine the matter as backward rotation, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 100 milliseconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | |
|---|---|
| Other | Engine restart from auto idle stop |
Malfunction Threshold
The crankshaft pulse is other than the expected amount when the engine is restarted from auto idle stop, but the PCM cannot determine the matter as backward rotation.
Possible Cause
- CKP sensor failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC, the freeze data, and the on-board snapshot are stored.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.