Protege LX L4-1489cc 1.5L DOHC MFI (1998)
Engine Control Module: Testing and Inspection
Without SSTs (NGS Tester)
VREF (Voltage Reference) Test
VREF TERMINAL TEST WITHOUT SSTs TESTER
1. Turn the ignition switch to ON.
2. Measure the voltage between the throttle position sensor connector (vehicle side) terminal A and body ground by using a voltmeter.
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When the measurement voltage is 0 V
(1) Turn the ignition switch off.
(2) Disconnect the throttle position sensor connector, EGR boost sensor connector, and fuel tank pressure sensor connector (which is applied
Vref).
(3) Verify there is no continuity between the throttle position sensor connector (vehicle side) terminal A and body ground by using an
ohmmeter.
(4) If there is continuity, repair the related harness.
(5) Inspect continuity between the PCM connector (vehicle side) terminal 31 and each sensor connector (vehicle side) terminals which is
applied Vref by using an ohmmeter.
(6) If there is continuity, repair the related harness.
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When the measurement voltage is B+
(1) Turn the ignition switch OFF.
(2) Disconnect the battery positive harness and battery negative harness.
(3) Verity there is no continuity between the throttle position sensor connector (vehicle side) terminal C and battery positive harness by using
an ohmmeter.
(4) If there is continuity, repair the related harnesses.
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When the measurement voltage is approximately 5 V
(1) Vref terminal (31) of PCM is okay.
Ground Terminal Test
GROUND TERMINAL TEST WITHOUT SSTs TESTER
