Vehicle Speed Sensor A Intermittent/Erratic/High

What it means

The engine computer has detected that the vehicle speed signal drops out, jumps suddenly or reads higher than is plausible. The usual cause is an unstable connection in the connector or wiring, or electrical interference on the signal.

Related codes: P0500P0501P0502P0720

Symptoms4

• Speedometer needle jumps or drops suddenly while driving.
• Sudden or unexpected transmission shifts.
• Cruise control disengages on its own.
• Check engine light that comes and goes.

Possible causes5

• Loose connector or corroded pins causing an intermittent connection.
• Cracked wires that break contact with vibration or engine movement.
• Electrical interference from ignition wires or add-on devices such as lighting or trackers.
• Damaged tone ring producing irregular pulses.
• Weak sensor that cuts out when hot.

How to diagnose5

1. Watch vehicle speed on a scan tool while driving and note when the reading jumps.
2. Gently wiggle the wiring and connector while watching the reading to find an intermittent connection.
3. Check the signal waveform on an oscilloscope for extra or missing pulses.
4. Look for add-on electrical devices near the sensor wiring.
5. Inspect the tone ring and sensor after removal.

How to fix5

1. Clean the connector and secure it properly.
2. Repair the cracked wire and route it away from heat and interference.
3. Disconnect or reinstall any add-on device that causes interference.
4. Replace the sensor or tone ring if proven faulty.
5. Clear the codes, then road test long enough to confirm the code does not return.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The fix is often a simple connector or wire repair, and the cost rises if a new sensor or tone ring is needed.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions