P0813: Reverse Output Circuit OBD-II Trouble Code

A P0813 OBD-II code indicates an issue with the vehicle’s reverse output circuit, which may cause the reverse lights to work intermittently or not at all.
The purpose of the reverse input sensor is to tell the PCM that the transmission is in reverse, and when it’s detected that the signal is lost or if there is a  voltage irregularity, it will trigger a P0813 code.

How Serious is a P0813 Code?

A P0813 code isn’t a huge issue by any means, but it indicates an electrical problem on the reverse output circuit. This circuit controls function of your reverse lights, and may cause them to not light up as they’re supposed to.

P0813 Symptoms

Common symptoms of a P0813 may often include:

  • Reverse lights not working
  • Reverse lights constantly on

What Causes a P0813 Code?

  • Damaged wiring and / or plug connectors
  • Failed reverse input switch
  • Failed reverse position sensor
  • Bad neutral safety switch
  • PCM or programming error(s)

How to Diagnose a P0813 Code?

When first attempting to properly diagnosing a P0813 code, the first step is to assess the current condition of the existing wiring and and connectors on the circuit.  The key thing to look for with a P0813 is to see if there’s any signs of the wiring causing a short, wires are frayed wires, or otherwise damaged.

In addition, the connectors in the system should be looked at as well.  Common signs of connector failure include corrosion or broken pins.

Once the wiring and connectors are looked into and are found to be in good shape, the next assessment needs to be of the reverse input switch as well as fuses and bulbs in the circuit.

How to Repair or Fix P0813?

  • Repair or replace any damaged wiring or connectors – Replace connectors if corroded or broken
  • Replace reverse input switch