P0339
DTC P0339 Crankshaft Position Sensor "A" Circuit IntermittentCIRCUIT DESCRIPTION
DTC Detecting Condition:
The crankshaft position sensor system consists of a crankshaft position sensor plate and a pick-up coil. The sensor plate has 34 teeth and is installed on the crankshaft. The pick-up coil is made of an iron core and magnet. The sensor plate rotates and as each tooth passes through the pick-up coil, a pulse signal is created. The pick-up coil generates 34 signals for each engine revolution. Based on these signals, the ECM calculates the crankshaft position and engine RPM. Using these calculations, the fuel injection time and ignition timing are controlled.
Reference: INSPECTION USING OSCILLOSCOPE
During cranking or idling, check the waveforms between terminals G2 and NE-, and NE and NE- of the ECM connector.
HINT: The correct waveforms are as shown in the illustration.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds:
If there is no signal from the crankshaft sensor even though the engine is revolving, the ECM interprets this as a malfunction of the sensor.
Wiring Diagram:
INSPECTION PROCEDURE
Step 1 - 2:
Step 3 - 4:
HINT:
- Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame records the engine conditions when a malfunction is detected. When troubleshooting it is useful for determining whether the vehicle was running or stopped. the engine was warmed up or not, the air-fuel ratio lean or rich, etc. at the time of the malfunction.
- READ VALUE ON HAND-HELD TESTER OR OBD II SCAN TOOL
a. Connect the hand-held tester or the OBD II scan tool to the DLC3.
b. Start the engine and push the hand-held tester or the OBD II scan tool main switch ON.
c. When using hand-held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / ENGINE SPD.
- The engine speed can be confirmed in DATA LIST using the hand-held tester or OBD II scan tool. If there is are NE signals from the crankshaft position sensor despite the engine revolving, the engine speed will be indicated as zero. If voltage output of the crankshaft position sensor is insufficient, the engine speed will be indicated as lower RPM (than the actual RPM).