Protege LX L4-1489cc 1.5L DOHC MFI (1998)
Vehicle Speed Sensor: Testing and Inspection
SENSOR SIGNAL INSPECTION PROCEDURES
1. Find an unusual signal (Refer to procedures below).
2. Locate its source (Refer to procedures below).
3. Repair or replace the defective part.
4. Confirm that the unusual signal has been erased.
While referring to the diagnostic trouble code inspection section of the on-board diagnostic system, use the PID monitor to check the input signal
system relating to the problem.
1. Turn the ignition ON and idle the vehicle. You can assume that any signals that are out of specifications by a wide margin are unusual.
2. When recreating the problem, any sudden change in monitor input signals that is not consciously created by the driver can be judged as
unusual.
CAUTION:
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Compare the NGS monitor voltage with the measurement voltage using the NGS "DIGITAL MEASUREMENT SYSTEM" function. If you use
another tester, misreading may occur.
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When measuring voltage, attach the tester ground to the GND of the PCM that is being tested, or to the engine itself. If this is not done, the
measured voltage and actual voltage may differ.
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After connecting the pin to a waterproof coupler, confirming continuity and measuring the voltage, check the waterproof connector for cracks. If
there are any, use sealant to fix them. Failure to do this may result in deterioration of the harness or terminal from water damage, leading to
problems with the vehicle.
VEHICLE SPEED SENSOR SIGNAL INSPECTION
1. Measure the #1 PCM terminal voltage and confirm that it is at 0 V or 5 V when the ignition switch is ON and the engine at idle.
(1) If it is at 0 V or 5 V, proceed to "Intermittent Diagnostic Test".
(2) If not, check the following points concerning the PCM connector. If there is no problems, proceed to next step.
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Female terminal opening loose
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Coupler (pin holder) damage
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Pin discoloration (blackness)
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Harness/pin clamp is loose or disconnected
2. Measure the #2 sensor terminal voltage and confirm that it is at 0 V or 5 V when the ignition switch is ON and the engine at idle.
(1) If it is at 0 V or 5 V, proceed to "Intermittent Diagnostic Test".
(2) If not, check the following points concerning the sensor connector: If there are no problems, proceed to next step.
-
Female terminal opening loose
-
Coupler (pin holder) damage
-
Pin discoloration (blackness)
-
Harness/pin clamp is loose or disconnected
3. Confirm that the #3 terminal switch voltage is at 0 V.
(1) If it is at 0 V, inspect the sensor. If necessary, replace the sensor.
(2) If not at 0 V, check the following points:
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Open circuit in harness
-
Female terminal opening loose
-
Coupler (pin holder) damage
-
Pin discoloration (blackness)
-
Harness/pin clamp is loose or disconnected.
