Engine General Information and Diagnosis: 1A-133
3 A/C refrigerant pressure sensor power supply circuit
check
1) Disconnect connectors from MAP sensor with ignition
switch turned OFF.
2) Turn ON ignition switch, measure voltage between
engine ground and “GRY/RED” wire terminal of A/C
refrigerant pressure sensor connector.
Is voltage 4 – 6 V?
Faulty MAP sensor. “GRY/RED” wire is open
or shorted to power
circuit.
4 A/C refrigerant pressure sensor signal circuit check
1) Turn ON ignition switch, measure voltage between
engine ground and “RED” wire terminal of A/C
refrigerant pressure sensor connector.
Is voltage 4 – 6 V?
Go to Step 6. Go to Step 5.
5 A/C refrigerant pressure sensor signal circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “RED” wire terminal of A/C
refrigerant pressure sensor connector and “E23-55”
terminal of ECM connector.
Is resistance below 2
Ω
?
“RED” wire is shorted to
power supply circuit.
“RED” wire is open or
high resistance circuit.
6 A/C refrigerant pressure sensor ground circuit check
1) Turn OFF ignition switch, measure resistance between
engine ground and “ORN” wire terminal of A/C
refrigerant pressure sensor connector.
Is resistance below 5
Ω
?
Go to Step 8. Go to Step 7.
7 ECM ground circuit check
1) Remove ECM from its bracket with ECM connectors
connected.
2) Measure resistance between engine ground and “E23-
54” terminal of ECM connector.
Is resistance below 5
Ω
?
“ORN” wire is open or
high resistance circuit.
ECM grounds “E23-31”,
“C37-58”, “C37-15” and/
or “C37-30” is open or
high resistance circuit.
8 A/C refrigerant pressure sensor check
1) Check A/C refrigerant pressure sensor referring to “A/C
Refrigerant Pressure Sensor and Its Circuit Inspection in
Section 7B” or “A/C Refrigerant Pressure Sensor and Its
Circuit Inspection in Section 7B”.
Is it good condition?
Substitute a known-
good ECM and recheck.
Faulty A/C refrigerant
pressure sensor.
Step Action Yes No