Code 27 - Left Front Wheel Speed Sensor Continuity Fault
Toothed wheel generates a voltage pulse as it moves past sensor. EBTCM/EBCM uses these pulses to determine wheel speed. EBTCM/EBCM uses wheel speed sensor signal to calculate vehicle reference speeds and speed, acceleration and slip values for each wheel. These values are used to determine when anti-lock control is needed. Code 27 is set if there is a short to voltage or an open in circuits No. 830 or 873, or faulty speed sensor. Testing for this fault occurs with ignition on and vehicle not moving.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- Checks for correct resistance in sensor.
- Checks for a short to battery in either speed sensor circuit wire.
- Checks for an open in both speed sensor circuit wires.
- Manipulates wiring and connectors, trying to induce an intermittent fault not currently present.
- Checks if code resets at key on.
- Checks if Code 25 sets during road test.
- Code 27 sets when vehicle is at rest. Code 25 sets with a problem in speed sensor circuitry with vehicle in motion.
- Wheel speed sensor may be causing an intermittent fault.