1990 Subaru XT 1.8 5FACTORY OEM SERVICE PROCEDURE

Crank Angle Sensor

For testing information, see TESTS W/CODES article.

DETONATION (KNOCK) SENSOR RESISTANCE (1)

Application Ohms
All Models 532,000-588,000
(1) Measure resistance between ground and connector terminal.
OXYGEN SENSOR VOLTAGE (1)

Application Volts
All Models 0.1-0.9
(1) With engine running at normal operating temperature, quickly snap throttle open and closed. Measure voltage between oxygen sensor connector terminal and ground. Voltage should vary within specification.
THROTTLE POSITION SENSOR (TPS) RESISTANCE (TOTAL RESISTANCE)

Application (1) (2) TPS Connector Terminals Total: Ohms
Legacy Black & Red 12,000
Loyale
1.8L PFI Black & White 6000-18,000
1.8L TBI Black & Red 3500-6500
XT & XT6 Black & White 6000-18,000
(1) Justy 1.2L carbureted & PFI engines are not equipped with TPS.
(2) Disconnect TPS connector. At component side of connector, connect ohmmeter between these terminals.
THROTTLE POSITION SENSOR (TPS) RESISTANCE (VARIABLE RESISTANCE)

Application (1) (2) TPS Connector Terminals Variable: Ohms
Legacy
Throttle Closed Black & White 1000
Throttle Open Black & White 4300
Loyale 1.8L PFI
Throttle Closed Black & Red More Than 2400
Throttle Open Black & Green Less Than 1000
XT & XT6
Throttle Closed Black & Green 5800-17,800
Throttle Open Black & Green 1500-5100
(1) Justy 1.2L carbureted & PFI engines are not equipped with TPS.
(2) Disconnect TPS connector. At component side of connector, connect ohmmeter between these terminals.
THROTTLE SWITCH (IDLE SWITCH) CONTINUITY

Application (1) (2) Terminals
Justy 1.2L PFI (3) Blue/White & Black/Red
Legacy Brown & Black
Loyale
1.8L PFI Blue/White & Black/Red
1.8L TBI Light Green & Black
XT Blue/White & Black
XT6 Green/Yellow & Black
(1) Justy 1.2L carbureted models are not equipped with throttle switch.
(2) On all models except Loyale PFI, disconnect TPS connector. On Loyale PFI, disconnect throttle switch connector. On all models, check continuity between indicated terminals of connector. There should be continuity with throttle closed and no continuity with throttle open.
(3) In addition to idle switch function, throttle switch also contains wide open throttle switch function. To test wide open throttle switch function, check continuity between Green/Red and Black/Red wire terminals of throttle switch connector. There should be continuity with throttle fully open (at least 50 degrees) and no continuity with throttle closed.
Chapter Navigation
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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.