General Precautions of EFI System Maintenance
F-64
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
P0501
P0501
Maintenance tips:
The malfunction has been confirmed, and the
following problems may possibly exist
1) The circuit for the Pin 59# of ECU connected to
the vehicle speed signal sensor open circuit or
short to ground.
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 59# for connector of ECU connected to
the vehicle speed signal sensor.
2) Inspect the electric resistance for the Pin 59# of
ECU to ground.
79. P0506 Idling Speed Control Rotational Speed Higher than Target Idling Speed
Description about Malfunction Cause:
The idling rotational speed of electronic throttle is actuated by ECU control DC motor and achieved through
throttle opening controlled by drive mechanism. If ECU commands the idling speed equals to target value, but
the actual engine speed is still lower than the target idling speed by certain value, it is then determined to be
the malfunction of small opening jam.
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
P0506
P0506
Maintenance tips:
The malfunction has been confirmed, and the
following problems may possibly exist
1) Deviation in processing size for throttle body
2) Inside of throttle body too dirty
3) Stepping motor failed
Maintenance tips:
The malfunction has not been finally confirmed, and
it is possibly a random malfunction.
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