P2684 code meaning
Actuator Supply Voltage C Circuit/Open
Powertrain system Generic code P26xx codes Check engine light
What P2684 means
Some transmission controllers power groups of solenoids through several internal high-side outputs; supply C is the third of these rails, after A (P0657) and B (P2669). P2684 reports an open load on it. GM's 2023 and 2024 TCM tables tie the code to high-side output 7 and test it while the module powers down: with the output off and a low-side driver on, the load should drag the line low, so a level above 40 % of battery voltage is remembered as an open load and reported after the next start, Type A. Ford's 2024 summary assigns P2684 to high side driver 7 of the TR9070 dual-clutch gearbox, and Ford's 2014 Boss 302S code list carries it as well. Whatever hangs on that rail stops working, so a default gear or limp mode is likely.
P2684 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2684
- Transmission in default gear or limp mode
- MIL on after restart
- Several solenoid circuit codes stored together
Common causes of P2684
- Most likelyBroken wire or loose terminal between the module output and the supplied solenoids
- PossibleCorroded or unseated transmission connector or internal lead frame
- Less likelyHigh-side output inside the controller defective
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Actuator supply cControl moduleWiring harness
What each part of P2684 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 6 | Area: computer (engine control module) and output circuits. |
| 84 | The exact fault in that area. |
What to do next
- Note P2684 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2684
What does P2684 mean?
P2684 means "Actuator Supply Voltage C Circuit/Open". Some transmission controllers power groups of solenoids through several internal high-side outputs; supply C is the third of these rails, after A (P0657) and B (P2669). It is a generic code, so it means the same on every make.
Is it safe to drive with P2684?
Drive gently and only to a workshop. With P2684 the car can go into limp mode (reduced power) to protect itself.
Will P2684 fail an emissions test?
Yes, it can. P2684 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2684 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P2684 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.