Toyota Corolla (E170) 2014–2019 Owners Manual / Instrument cluster / Gauges and meters (multi-information display) / Instrument panel light control
Toyota Corolla (E170): Instrument panel light control
When the tail lights are on, the brightness of the instrument panel lights can be adjusted. (On vehicles with an automatic light control system, the instrument panel lights can be adjusted when the surrounding area is dark and the tail lights are on.) The brightness of the clock light can be adjusted regardless of whether the tail lights are on or off.
1 Brighter
2 Darker

Other materials:
Inspection procedure
1 Check p squib circuit(airbag sensor assy center – instrument
panel passenger airbag assy)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the airbag sensor
assy center and the instrument panel ...
On–vehicle inspection
1. Inspection throttle body idle speed control valve assy
Notice:
it is impossible to check the resister value and the operation
of isc valve by itself, because the isc valve
has an ic circuit inside it, which transforms the duty
signal from the ecm to the derive signal.
After check ...
Inspection procedure
1 Check security indicator light
Remove the security indicator.
check the indicator light, as shown in the illustration and
table.
Standard:
2 Check wire harness (tvip ecu security indicator)
Disconnect the tvip ecu and security indicator connectors.
  ...


