Mounted on the rear of the 6-speed automatic transmission (6R80) extension housing, reading reluctor ring on output shaft
Pins
3-pin connector
0
Timebase
5ms/div at city speeds, 2ms/div at highway speeds
Voltage Scale
5V/div
Trigger
6V, rising edge
Wiring
Orange/Yellow (signal), Gray/Black (power, 12V), and Black/White (ground)
Expected Voltage Range
At Idle
0V to 0V
At Higher RPM
0.5V to 12V
Expected Pattern
Digital square wave signal switching between 0.5V (low) and 12V (high). Frequency increases proportionally with vehicle speed. At 60 mph, frequency is approximately 320-340 Hz from the output shaft reluctor ring. Signal shows 50% duty cycle with clean transitions
Known-Good Waveform
Clean digital square wave with amplitude ranging from near 0V to 12V. Pulse frequency should increase smoothly and proportionally with vehicle speed without dropouts or missing pulses. At constant highway cruising speed, the waveform should show perfectly consistent pulse spacing and uniform amplitude. The signal should be present whenever the vehicle is moving, even at very low speeds (below 5 mph).
Common Failure Patterns
No signal output while vehicle is moving, flat line at 0V or 12V
Cause: Failed VSS hall-effect sensor, broken output shaft reluctor ring, or open circuit in wiring harness
The PCM compares the transmission VSS signal with ABS wheel speed sensors for rationality. If VSS fails but wheel speed sensors are good, speedometer and cruise control will still function using calculated speed from wheel sensors. On 4WD models, verify transfer case is not slipping as this affects VSS accuracy. Check for transmission fluid leaks at VSS mounting location which can cause sensor contamination.
Related Diagnostic Trouble Codes
P0500P0501P0502P0503
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.