1. Connect the connector to the panel light control switch.
2. Connect the negative battery cable.
3. Measure the voltage at the panel light control switch using voltmeter.
4. If the value are not as specified in the Terminal Voltage List (Reference), inspect the parts under Action and related wiring harnesses.
5. If the system does not work properly even though the parts or related wiring harnesses do not have any malfunction, replace the panel light control switch.
Terminal Voltage Table (Reference)


Terminal C inspection
1. Measure the wave pattern of the terminal C on the panel light control switch using an oscilloscope.

2. Set the headlight switch to either the TNS or headlight position.
3. Set the panel light control switch to the brightest position.
4. Verify that the pattern on the screen is as shown in the figure.

5. Verify that the pattern on the screen matches the pattern shown in the figure as the panel light control switch is gradually turned to the darkest position.

Panel light control switch removal/installation
Wiper and washerMazda 6 Service Manual: Mechanical system test
Mechanical System Test Preparation
1. Engage the parking brake and use wheel chocks at the front and rear of the
wheels.
2. Inspect the engine coolant. (See ENGINE COOLANT LEVEL INSPECTION.)
3. Inspect the engine oil. (See ENGINE OIL INSPECTION.)
4. Inspect the ATF levels. (See AUTOMATIC TRANS ...
Mazda 6 Service Manual: Engine Coolant Temperature Gauge
Displays the engine coolant temperature. The blue gauge indicates that the engine
coolant temperature is low, and the red gauge indicates that the engine coolant
temperature is high and overheating.
CAUTION
If the high engine coolant temperature warning light (red) turns on, there
is a pos ...