Circuit Description

A toothed wheel mounted on output shaft of transmission generates an AC voltage pulse as it moves past Vehicle Speed Sensor (VSS). VSS contains a permanent magnet surrounded by a coil of wire, which produces a magnetic field. As toothed ring interrupts magnetic field, an AC pulse is generated. As vehicle speed increases, AC voltage pulse also increases.

DTC will set when following conditions are present:

• DTCs P0107, P0108, P0117, P0118, P0121, P0122, P0123, P0125, P0506 and P0507, P1120, P1220 or P1221 not set.
• Engine coolant temperature greater than 95°F (35°C).
• Engine speed greater than 1000 RPM.
• TP sensor angle greater than 5 percent.
• MAP between 40-100 kPa with A/C off.
• MAP between 45-100 kPa with A/C on.
• Conditions met for 2 seconds.
• PCM detects vehicle speed at zero MPH for 50 seconds.