900 SE Convertible L4-1985cc 2.0L DOHC Turbo EFI (1998)
Shift Up Lamp: Description and Operation
The lamp is situated in the main instrument display panel and supplied with current from the + 15 circuit. It is controlled from pin 55 of the engine
control module and tested for, 3 seconds when the ignition is switched on.
A combination of light engine load and high engine revs when the car is being driven will cause the lamp to light up. This does not apply to 5th gear.
The lamp lights up regardless of engine load when engine speed approaches 6,000 rpm.
The ECM calculates the gear position on the basis of engine speed and vehicle speed.
