P0408: Exhaust Gas Recirculation Sensor B Circuit High
What to do
Usually driveable with no symptom beyond the warning light.
What this code means
The second EGR position sensor is reading above its plausible range — the counterpart to the sensor B low-circuit fault, and diagnosed the same way as sensor A high. An open ground on the sensor or a signal wire picking up a supply voltage account for most cases.
Likely causes
Start here
- Faulty EGR position sensor · easy
- Open sensor ground circuit · moderate
- Corroded or loose connector · easy
Less common
- Signal wire shorted to voltage · moderate
Symptoms
Components involved
Information, not instruction
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Community experience
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