DTC P0340

DTC P0340: Camshaft Position (CMP) Sensor A No Signal

General Description

Courtesy of HONDA, U.S.A., INC.

Camshaft position (CMP) sensor A consists of a rotor and a semiconductor that detects rotor position and intake camshaft timing. When the rotor turns after starting the engine, the changes of magnetic flux in the semiconductor are converted into pulsing signals to the powertrain control module (PCM). CMP sensor A also detects the top dead center of each cylinder for fuel injection. The PCM determines the camshaft position according to the signals from the crankshaft position (CKP) sensor and CMP sensor A. If no pulsing signals from CMP sensor A are detected, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	-
DTC Type	Two drive cycles, MIL on

Enable Conditions

Condition
State of the engine	Running

Malfunction Threshold

No input signals from CMP sensor A are detected while signals from the CKP sensor are detected at least 50 times.

Possible Cause

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

CMP sensor A CAM line open
CMP sensor A CAM line short to ground
CMP sensor A VCC line open
CMP sensor A SG line open
CMP sensor A failure
PCM internal circuit 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 and the freeze data 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, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.