Exhaust Gas Recirculation Sensor B Circuit High
The engine computer detected that the EGR (Exhaust Gas Recirculation) sensor B circuit voltage is abnormally high, typically shorted to battery voltage or the 5V reference supply. This prevents the sensor from accurately reporting exhaust gas recirculation flow, causing the system to malfunction and increasing emissions.
What You Might Notice
- Check Engine Light (MIL) illumination
- Engine surging or power fluctuations while driving
- Intermittent stalling or rough idle
- Increased exhaust emissions and combustion temperatures
- Possible rough acceleration or hesitation
Most Common Causes
- 1
EGR sensor signal circuit shorted to battery voltage
The sensor's signal wire is directly contacting positive battery voltage, causing the circuit voltage to remain high and preventing proper sensor readings.
- 2
EGR sensor shorted to 5V reference circuit
The sensor signal line is cross-connected or shorted to the 5-volt reference wire, causing abnormally high voltage readings.
- 3
Faulty EGR sensor
The sensor itself has developed an internal short or is producing erratic high-voltage signals that exceed normal operating parameters.
- 4
Damaged wiring or corroded connector
Wiring insulation damage, corrosion, or loose connectors on the EGR sensor circuit can cause unintended connections to power sources.
How to Diagnose It
- 1
Check EGR sensor signal circuit shorted to battery voltage — The sensor's signal wire is directly contacting positive battery voltage, causing the circuit voltage to remain high and preventing proper sensor readings.
- 2
Check EGR sensor shorted to 5V reference circuit — The sensor signal line is cross-connected or shorted to the 5-volt reference wire, causing abnormally high voltage readings.
- 3
Check Faulty EGR sensor — The sensor itself has developed an internal short or is producing erratic high-voltage signals that exceed normal operating parameters.
- 4
Check Damaged wiring or corroded connector — Wiring insulation damage, corrosion, or loose connectors on the EGR sensor circuit can cause unintended connections to power sources.
How to Fix It
- 1
Inspect and repair EGR sensor wiring
Visually inspect the EGR sensor harness and connectors for damage, corrosion, or loose connections. Repair or reseat connectors as needed, and replace any damaged wiring.
- 2
Replace the EGR sensor
If wiring inspection reveals no faults, the EGR sensor is likely faulty and producing high voltage signals. Remove and replace the sensor with a new OEM or quality aftermarket unit.
- 3
Check and repair ground connections
Verify that the EGR sensor ground connection is secure and not corroded. Clean or replace the ground wire if necessary to ensure proper circuit return path.
- 4
Clear code and perform diagnostic drive cycle
After repairs, clear the trouble code using a diagnostic scanner and perform a drive cycle to verify the fix. Monitor for code return to confirm the repair was successful.
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