Powertrain
generic / SAE
P078F
Transmission Mode Switch C Circuit
General electrical fault on the third transmission mode select switch input C — used for additional drive modes (Sport, Snow, Tow/Haul, Eco) on transmissions that offer more than two operator-selectable shift maps. Without a valid input the TCM falls back to the default mode.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number7 / 8F
Possible causes
- Open or shorted switch wire high
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: possible
- Estimated cost: 60–350 €
- Estimated time: 0.3–1.5 h
- Component: transmission mode switch c
- Component: wiring harness
- MIL / check engine light
Sources
References
sae:J2012