Throttle Position Sensor Test - Mercury 150 EFI Service Manual

Throttle Position Sensor Test

a -
Purpose: Determines whether Throttle Position Sensor is functioning properly through the use of the Digital
Diagnostic Terminal (DDT). The Throttle Position Sensor is not adjustable.
1. Place outboard in water, connect Digital Diagnostic Terminal (DDT) to engine.
NOTE: If throttle position sensor is not functioning, #4 LED indicator light on DDT will be
illuminated.
2. Start engine, allow to warm up. Using DATA MONITOR portion of DDT, access TPI
VOLTS.
Results: As throttle is advanced, numerical value on DDT display should increase. As throttle is retarded,
numerical value should decrease.
HEAT TEST
With engine at idle, heat the TPS (with a hot air gun) below the electrical connection until
warm to the touch. Watch for any one or a combination of the following symptoms:
RPM change
Check engine light illumination
Momentary warning horn signal
TPS voltage value change (1/2 volt) on DDT
NOTE: Excessive heat will damage TPS.
90-883728 JULY 2001
a
Throttle Position Sensor
FUEL INJECTION
58871
Page 3B-33