General Precautions of EFI System Maintenance
F-53
67. P0343 Phase Sensor A Short to Power Supply
Description about Malfunction Cause:
The operation principle for phase sensor is to use Hall component to induce a triggered wheel that rotates
along with the camshaft, thus to monitor the position of camshaft. The phase signals received by ECU shall be
changing alternately on a regular basis between high level and low level, and ECU shall determine the circuit
of phase signal short to power supply if phase signals located at high level are successively detected.
Schematic Circuit:
Malfunction Diagnostic Guide:
Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and
Correct Circuit Diagram)
Step I: Use diagnostic instrument to read the malfunction information
Read Result I Read Result II
MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present
P0343
P0343
Maintenance tips:
The malfunction has been confirmed, and the
following problems may possibly exist
1) The circuit connected to the Pin 79# of ECU and
the circuit for the Pin 3# of phase sensor in short
circuit
2) The circuit connected to the Pin 79# of ECU and
the other power supply circuit in short circuit。
Maintenance tips:
The malfunction is not ultimately confirmed and it
may possibly be a random malfunction. Inspect the
following items:
1) Inspect the electric resistance of the circuit for
the Pin 79# of ECU to power supply.
2) Inspect the electric resistance of the circuit for
the Pin 79# of ECU and the circuit for the Pin 3#
of phase sensor.
68. P0365 Phase Sensor B Installation Position Improper
Description about Malfunction Cause:
The operation principle for phase sensor is to use a Hall component to induce a signal wheel to rotate along
with the camshaft, thus to monitor the position of camshaft. The phase signal received by ECU shall be
changing alternately on a regular basis between the high level and the low level, and ECU shall determine that
malfunction exists with the phase signal, when only slow change in high and low levels is detected.
Schematic Diagram:
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