General Precautions of EFI System Maintenance
F-19
19. P0103 Air Flow Meter Sensor Voltage Signal Too High
Description about Malfunction Cause:
The signal of air flow meter sensor is obtained by the transformation of temperature difference signal to
voltage signal. After the start of engine, if the continuously checked voltage signal of air flow meter sensor is
above the threshold value, high voltage failure is determined by the system.
Schematic Circuit:
Malfunction Diagnostic Guide:
Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function)
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
P0102
P0102
Maintenance tips:
The malfunction has been confirmed, and the
following problems may possibly exist
1) The circuit connected to the Pin 37# of ECU and
the circuit of the Pin 33# of ECU in short circuit
2) The circuit connected to the Pin 37# of ECU and
the other power supply short circuit
3) The circuit connected to the Pin 37# of ECU and
the main relay short circuit
Maintenance tips:
The malfunction has not been finally confirmed.
Please wait for system to fulfill diagnosis.。
1) Measure the electric resistance of the circuit
between the Pin 37# of ECU and the Pin 33# of
ECU.
2) Measure the electric resistance of the circuit
between the Pin 37# of ECU and the other
power supply.
3) Measure the electric resistance of the circuit
between the Pin 37# of ECU and the main relay.
20. P0112 Intake Temperature Sensor Signal Voltage Over-Low
Description about Malfunction Cause:
After engine has been started, ECU performs continuous monitoring over the intake temperature, and it will
be determined to be circuit of intake temperature sensor short to ground, if it is found that the engine intake
temperature exceeds the system set lower limit value.
Schematic Circuit:
Main relay
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