Troubleshooting
DTC P1340 CAMSHAFT POSITION SENSOR "A" (BANK 1 SENSOR 2)HINT:
- DTC P1340 indicates a malfunction related to the camshaft position (CMP) sensor (+) circuit.
- DTC P1341 indicates a malfunction related to the camshaft position (CMP) sensor (-) circuit.
CIRCUIT DESCRIPTION
DTC Detection Condition:
The camshaft position (CMP) sensor, like the crankshaft position (CKP) sensor, consists of a magnet and an iron core wrapped in copper wire. The camshaft has a tooth and the CMP sensor is installed so that it can detect the tooth passing by. When the camshaft rotates and the tooth pass by the CMP sensor, the magnet on the CMP sensor creates a magnetic field and voltage is generated in the copper wire. When the camshaft makes one full rotation, voltage will be generated in the CMP sensor once. The CKP sensor is roughly the same. When the crankshaft makes one rotation, its 34 teeth pass by the CKP sensor and voltage is generated 34 times. The camshaft rotates at half the speed of the crankshaft. Therefore, the CMP sensor generates voltage once in the time the crankshaft makes 2 rotations.
The Engine Control Module (ECM) detects generation of these voltages to indicate the cylinder.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds:
Component Operating Range:
If there is no signal from the camshaft position (CMP) sensor even though the engine is turning, or if the rotation of the camshaft and the crankshaft is not synchronized, the ECM interprets this as a malfunction of the sensor.
Wiring Diagram:
Step 1:
Step 2 - 3:
Step 4:
INSPECTION PROCEDURE
WAVEFORMS (REFERENCE)
a. Camshaft position (CMP) sensor
b. Crankshaft position (CKP) sensor
NOTE: The wavelength becomes shorter as engine rpm increases.
HINT: Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.