P0816
Downshift Switch Circuit
- Severity
- Low
- Driving
- No driving restriction
A fault in the downshift switch circuit - the paddle or lever switch that lets the driver request a manual shift down. The transmission will keep shifting automatically; what is lost is the driver's ability to ask for a gear.
Possible causes
- CommonFailed or worn downshift switch
- CommonWiring fault in the steering column or console
- CommonDamaged clock spring, on steering-wheel-mounted paddles
- PossibleCorroded or disturbed connector after column or console work
- RareFailed control module input
What you might notice
- Manual downshift requests ignored
- Manual mode unavailable
- Transmission stuck in automatic mode
- Check engine light on
What to check, in order
- Watch the switch state on the live data screen while operating the paddle or lever.
- Check whether the other direction still works. One direction failing points at that switch; both failing points at the shared wiring or the clock spring.
- On steering-wheel paddles, suspect the clock spring - it is the part that wears, and horn or airbag faults alongside this confirm it.
- Inspect the connector if the column or console has been worked on recently.
- If an airbag warning light is on as well, treat the restraints side as the priority and do not work in the column with the battery connected.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Transmission
P0800P0801P0802P0803P0804P0805P0806P0807P0808P0809P0810P0811P0812P0813P0814P0815P0816P0817P0818P0819P0820P0821P0822P0823P0824P0825P0826P0827P0828P0829P0830P0831P0832P0833P0834P0835P0836P0837P0838P0839P0840P0841P0842P0843P0844P0845P0846P0847P0848P0849P0850P0851P0852P0853P0854P0855P0856P0857P0858P0859P0860P0861P0862P0863P0864P0865P0866P0867P0868P0869P0870P0871P0872P0873P0874P0875P0876P0877P0878P0879P0880P0881P0882P0883P0884P0885P0886P0887P0888P0889P0890P0891P0892P0893P0894P0895P0896P0897P0898P0899