Vehicle Speed Sensor
1972 Dodge Challenger · 400ci V8
Sensor Type
inductive
Waveform Type
ac-sine
Location
Not factory equipped - uses mechanical speedometer cable driven from transmission output shaft
Pins
Unknown
Timebase
N/A
Voltage Scale
N/A
Trigger
N/A
Wiring
N/A - mechanical cable system only
Expected Voltage Range
At Idle
0V to 0V
At Higher RPM
0V to 0V
Expected Pattern
Not applicable - mechanical speedometer system
Known-Good Waveform
The 1972 Dodge Challenger uses a mechanical speedometer cable that runs from the transmission tailshaft to the instrument cluster. A gear in the transmission output housing drives the flexible cable which mechanically rotates the speedometer needle. No electronic vehicle speed sensor exists on this vehicle.
Common Failure Patterns
Speedometer needle bouncing or erratic
Cause: Worn speedometer cable, dry cable requiring lubrication, or worn transmission speedometer gear
Speedometer inoperative
Cause: Broken speedometer cable or stripped transmission drive gear
Diagnostic Tips
Diagnose by disconnecting cable at transmission - it should spin smoothly when vehicle moves. Check for kinked cable housing or broken inner cable. Listen for squealing indicating dry cable needing graphite lubricant.
Related Diagnostic Trouble Codes
P0500P0501P0502P0503
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
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