P080C

What it means

P080C means the control unit has detected a low voltage condition in the control circuit of the upshift/skip shift solenoid. The module monitors the solenoid driver circuit and saw a voltage lower than expected for the commanded state, which points to a short to ground, a wiring fault or a failed solenoid or driver. Where this solenoid is fitted and what it does (for example forcing a skip shift in a manual gearbox) depends on the model and gearbox.

Symptoms

• Warning light on (engine management or gearbox warning, depending on the vehicle)
• Skip shift or upshift function not working, or working at the wrong time
• Shift indicator or shift behaviour not as normal
• Gearbox stuck in a gear, or harsh or unexpected shifts on some automatics
• Poorer fuel economy

Possible causes

• Skip shift or upshift solenoid control wire shorted to ground (chafed or damaged insulation)likely
• Faulty solenoid with an internal short or very low coil resistancelikely
• Corroded, damaged or water-contaminated connector or terminals at the solenoid or control unitpossible
• Damaged or leaking wiring harness near the gearbox, heat sources or moving partspossible
• Low or unstable supply or earth to the solenoid circuit (blown fuse, poor earth, weak battery)possible
• Faulty control unit output driver, or software needing an update where the manufacturer has issued onerare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting any other gearbox, supply voltage or battery codes, then check for manufacturer bulletins for the model.
2. Check the battery condition and charging voltage, as low voltage can set circuit faults.
3. Visually inspect the solenoid wiring and connectors for chafing, heat damage, water ingress, corrosion and bent or pushed-back pins.
4. Check the relevant fuses and relays and the earth connections using the wiring diagram for that vehicle.
5. Measure the solenoid coil resistance and compare it with the manufacturer specification, which varies by model and gearbox.
6. With the connector unplugged, test the control wire for a short to ground and for continuity back to the control unit.
7. Use a scan tool that supports actuator tests to command the solenoid and watch the circuit response, where the vehicle supports it.
8. If the wiring and solenoid test good, check the control unit supply, earths and output, and see whether a software update is specified.

How to fix

• Repair or replace the damaged wiring where a short to ground is found, using proper soldered and sealed repairs or the correct harness section.
• Replace the faulty solenoid, or the solenoid assembly where it is not sold separately, and refit seals correctly.
• Clean or replace corroded connectors and terminals, and fix any source of water ingress.
• Restore faulty fuses, supplies or earth connections and fix the cause of the failure.
• Replace or repair the control unit only once the wiring and solenoid are proven good, and apply any manufacturer-approved software update.
• Clear the code after repair and road test to confirm it does not return.

Can I keep driving?

Nearby codes

• P080BGenericUpshift/Skip Shift Solenoid Control Circuit Range/Performance
• P080DGenericUpshift/Skip Shift Solenoid Control Circuit High