Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Check Ambient Temperature Meter System Communication Circuit
- CHECK AMBIENT SENSOR POWER SUPPLY
.
- Disconnect the ambient sensor connector.
- Turn the ignition switch to ON.
- Measure the voltage between the ambient sensor connector and chassis ground.
Connector and terminal
(B480) No. 2 (+) - Chassis ground (-):
Is the voltage 4 V or more?
Yes
Go to 2 .
No
Check the harness for open or short between the fuse and ambient sensor.
- CHECK HARNESS BETWEEN AMBIENT SENSOR AND COMBINATION METER ASSEMBLY
.
- Disconnect the connector of combination meter assembly.
- Check harness between ambient sensor and combination meter assembly.
Connector and terminal
(B480) No. 1 - (i10) No. 24:
(B480) No. 2 - (i10) No. 23:
Is harness normal?
Yes
Go to 3 .
No
Repair or replace the harness.
- CHECK AMBIENT SENSOR
.
Check the ambient sensor.
Is the ambient sensor operating properly? Ref. to AIR CONDITIONER>AMBIENT SENSOR>INSPECTION .
Yes
Go to 4 .
No
Replace the ambient sensor.
- CHECK AMBIENT TEMPERATURE DISPLAY
.
- Connect the combination meter assembly connector.
- Install the 3 kΩ resistance between connector terminals of the ambient sensor.
Connector and terminal
(B480) No. 1 - No. 2:
- Turn the ignition switch to ON.
Does the ambient temperature display 25°C (77°F)?
Yes
Repair the poor contact between the ambient sensor and harness connector.
No
Go to 5 .
- CHECK CURRENT DATA
.
Display the [Ambient Air Temperature] data using Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS)>DATA MONITOR .
Is the ambient temperature of 25°C (77°F) output?
Yes
Go to 6 .
No
Replace the combination meter assembly. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .
- CHECK MFD
.
- Remove the MFD.
- Attach the ambient temperature display to another vehicle on which the ambient temperature display operates normally to check its operation.
Does the ambient temperature display 25°C (77°F)?
Yes
Replace MFD.
No
Replace the combination meter assembly. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.