WARNING: This page is about a different car, the 1991 Acura Legend and 1991 Acura Integra. However, it is still accessible from the selected car via links, so may be relevant.

Ensure 20-amp fuse No. 22 in underdash fuse box is okay. Disconnect 3-pin connector from speed sensor. Speed sensor is located next to oil filter.
Using an ohmmeter, check for continuity between Green/White wire and ground. See Fig 1 . If continuity exists, go to next step. If continuity does not exist, repair open between speed sensor and ECU ground. ECU ground is located next to throttle body.

Fig 1: Testing Vehicle Speed Sensor (Legend)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
With ignition on, measure voltage between Black/Yellow wire and ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Black/Yellow wire between speed sensor and underdash fuse box.
Measure voltage between Yellow/Red wire and ground. If voltage reading is about 5 volts, go to next step. If voltage is not 5 volts, repair Yellow/Red wire for short to ground.
Reconnect speed sensor connector. Raise and support vehicle. Connect voltmeter between Yellow/Red wire of sensor connector and ground. With ignition on and transaxle in neutral, block one front wheel and slowly rotate other front wheel. Voltage should pulsate between zero and 5 volts. If voltage is not between zero and 5 volts, replace speed sensor.

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.

Safety Warning

Vehicle Speed Sensor: Legend

Use the Manual With the Right Hardware

When to See a Mechanic