MPI – Troubleshooting
13-14
Code No. 25 Barometric pressure sensor system Probable cause
Range of Check
D Ignition switch: ON
D Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.
Set conditions
D Sensor output voltage is 4.5 V or more (corresponding to a barometric pressure
of 114 kPa or more) for 4 seconds.
or
D Sensor output voltage is 0.2 V or less (corresponding to a barometric pressure
of 5.33 kPa or less) for 4 seconds.
D Malfunction of the barometric pressure sensor
D Improper connector contact, open or short-circuited
harness wire of the barometric pressure sensor circuit
D Malfunction of the engine-ECU
Measure at the air flow sensor con-
nector A-25.
D Connect the connector. (Use
the test harness: MB991709)
D Voltage between 2 and earth
(Ignition switch: ON)
OK: 3.7–4.3 V (Altitude: 0 m)
3.2–3.8V (Altitude:
1,200 m)
NG
Measure at the air flow sensor con-
nector A-25.
D Disconnect the connector, and
measure at the harness side.
D Voltage between 1 and earth
(Ignition switch: ON)
OK: 4.8–5.2 V
D Continuity between 5 and earth
OK: Continuity
NG
Check the following connector:
B-62
NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between
the engine-ECU and the baromet-
ric pressure sensor connector.
NG
Repair
OK
Replace the engine-ECU.
OK
Check the following connector:
A-25
NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between
the engine-ECU and the baromet-
ric pressure sensor connector.
NG
Repair
OK
Replace the air flow sensor.
OK
Measure at the engine-ECU con-
nector B-62.
D Connect the connector.
D Voltage between 85 and earth
(Ignition switch: ON)
OK: 3.7–4.3 V (Altitude: 0 m)
3.2–3.8V (Altitude:
1,200 m)
NG
Check the harness wire between
the engine-ECU and the baromet-
ric pressure sensor connector, and
repair if necessary.
Check the following connector:
A-25, B-62
OK
Check trouble symptom.
NG
Replace the engine-ECU.
NG
Repair
OK
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