P0816: Downshift Switch Circuit OBD-II Trouble Code

Vehicles that have been manually shiftable automatic transmission automated manual transmission, use something called a downshift switch telling the ECU when you have used the gear lever paddle shifters to request a downshift. If there is a problem with the downshift switch, a P0816 DTC will be saved.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

How Serious is the Code?

Transmission problems resulting from a P0816 diagnostic trouble code are not likely to leave you stranded, but it might get stuck in limp mode, which would leave you restricted to a single forward gear.

Symptoms

Symptoms of a P0816 include:

  • Manual shifting function disabled
  • Limp Mode
  • Warning lights

Causes

  • Damaged wiring/connectors
  • Failed transmission gear selection switch
  • Failed downshift solenoid
  • Failed Normal/Performance switch

How to Diagnose the Code?

Often times, the cause of a P0816 OBDII trouble code is an electrical short. So a mechanic should start by inspecting the wiring and connectors, and then test the downshift switch itself.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

What Repairs Will Fix P0816?

  • Repair damaged wiring/connectors
  • Replace transmission gear selection switch
  • Replace downshift solenoid
  • Replace Normal/Performance switch

Related Codes

N/A