Reverse Output Circuit
The P0813 code means the vehicle's onboard diagnostic system has detected: Reverse Output Circuit. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $30 - $400 (parts and labor)
Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.
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Common Symptoms
- Check Engine Light illuminated
- Reverse lights do not turn on
- Backup camera and parking sensors inactive in reverse
- Other reverse-dependent systems may not function
Probable Causes (Ranked by Likelihood)
- Blown reverse light fuse Very High
- Faulty reverse light relay or output driver High
- Open or short in reverse output wiring Moderate
- TCM or body control module output failure Low
Step-by-Step Diagnostic Procedure
-
Check the reverse light fuse and replace if blown
-
Test for voltage at the reverse light connector when in reverse
-
Inspect wiring from TCM or BCM to reverse light circuit
-
Use a scan tool to command the reverse output and verify operation
Frequently Asked Questions
What is the difference between P0812 and P0813?
P0812 relates to the input circuit that tells the TCM reverse is selected. P0813 relates to the output circuit that the TCM uses to activate reverse lights and related systems.
Is it safe to drive without reverse lights?
Driving without reverse lights is illegal in most areas and is a safety hazard. Other drivers cannot see when you are backing up, especially at night.
Could a simple blown fuse cause P0813?
Yes, a blown fuse is the most common and least expensive cause. Always check the fuse box first before pursuing more complex diagnostics.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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