General Precautions of EFI System Maintenance
F-34
41. P0203 3
rd
-Cylinder Fuel Injector Control Circuit Open
Description about Malfunction Cause:
After engine has been started, the circuit voltage is to be measured by the drive module of fuel injector inside
ECU, and when voltage complies with the voltage in the mode of open circuit, it is determined to be a
malfunction of open circuit.
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
P0203 P0203
Maintenance tips:
The malfunction has been confirmed, and the
following problems may possibly exist
1) Whether or not the coil of fuel injector is in open
circuit
2) Whether or not the connection of the pin for
connector of fuel injector to the Pin #7 of ECU
is under good condition
3) Whether or not the connection of the pin for
connector of fuel injector to the main relay is
under good condition
Maintenance tips:
The malfunction is not ultimately confirmed and it
may possibly be a random malfunction. Inspect the
following items:
1) Whether or not the coil of fuel injector is in open
circuit
2) Whether or not the connection for the pin of
connector for fuel injector to the Pin 7# of ECU
is under good condition
3) Whether or not the connection of the pin for
connector of fuel injector to the main relay is
under good condition
Main relay
To Next Page
