Powertrain
generic / SAE
P077C
Output Shaft Speed Sensor Circuit Low
Output shaft speed sensor signal voltage below the lower limit — short to ground or open supply. TCM disables vehicle-speed dependent shift logic and may force limp-home.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number7 / 7C
Possible causes
- Signal wire shorted to ground high
- Connector pins corroded - high contact resistance low
- Harness chafing through insulation low
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 150–600 €
- Estimated time: 0.5–2 h
- Component: output shaft speed sensor
- Component: sensor wiring
- MIL / check engine light
Sources
References
sae:J2012