VSS Circuit Low Input
The POWERSTROKE-P0502 (Power Stroke) diesel fault code means: VSS Circuit Low Input. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- beginner
- Estimated cost
- $40-$200
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Common Symptoms
- Speedometer drops out
- Harsh shifts
- CEL
Probable Causes (Ranked by Likelihood)
- Failed VSS sensor on trans tailshaft Likely
- Damaged VSS wiring Likely
Step-by-Step Diagnostic Procedure
Scan VSS PID during driving.
Replace sensor.
Frequently Asked Questions
What is P0502 on a 7.3L Power Stroke?
P0502 on a 7.3L Power Stroke (1994-2003) indicates: VSS Circuit Low Input. This is a known diagnostic trouble code on this engine family and typically points to the causes listed above.
Can I drive with P0502 on my Power Stroke?
Yes, you can generally drive with this code, but diagnose it soon to prevent further damage.
How much does it cost to fix P0502?
Repair cost is typically $40-$200 depending on the underlying cause and whether you DIY or use a shop. Diagnostic time alone runs $100-$180 at most independent diesel shops.
P0502 on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown: