P1507

Vehicle Speed Sensor Intermittent Malfunction

Powertrain Transmission Control VSS intermittent signal 🟡 Moderate — Fix within a week ⚠️ Drive with Care
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What This Actually Means

In plain language — no jargon

Your vehicle's speed sensor is sending unreliable signals to the engine computer, like a radio that keeps cutting out. The ECU can't consistently read your vehicle speed, which affects transmission shifting and cruise control.

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Symptoms You May Notice

3 known symptoms for this code
Transmission shifts erratically or hesitates between gears
Cruise control malfunctions or disengages unexpectedly
Speedometer reads zero or fluctuates wildly
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECM monitors voltage pulses from the Vehicle Speed Sensor (VSS) to calculate vehicle speed and control transmission behavior. It detects intermittent signal loss when pulses drop out unexpectedly or become inconsistent, indicating a failing sensor or wiring issue.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
VSS Signal Frequency Continuous pulses proportional to wheel speed (4000+ RPM at 60 mph typical) Intermittent dropouts or signal loss detected over multiple drive cycles
Signal Voltage 0.5-5V AC/DC depending on sensor type Erratic spikes, dropouts, or below 0.3V during driving
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
VSS connector and wiring harness
Inspect for corrosion, loose pins, or damaged insulation at the sensor connector and wiring route.
2
Vehicle Speed Sensor (VSS)
Remove and replace the VSS unit, typically located on the transmission housing or rear axle.
3
Transmission output shaft seal and reluctor ring
Check for debris or damage to the reluctor ring that the sensor reads.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code P1507 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code P1507

What happens after you fix the fault

Once the fault is repaired, P1507 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.