Catalyst Heater Circuit Low Bank 1
The control or supply line to the electric catalyst heater on bank 1 is shorted to ground or measures below the expected voltage when the heater is commanded on.
Affected components
- Electric catalyst heater b1
- Catalyst heater wiring b1
Common causes
- High likelihood: Control line shorted to ground
- Medium likelihood: Heater element internally shorted
- Low likelihood: Connector pins corroded - high contact resistance
Possible symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.