What it means
Same as P2396 with the signal voltage below the plausible range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The position sensor on diesel intake air flow valve B reports the valve’s position to the control module. This code sets when the sensor signal falls below the plausible range, often because the signal wire is grounded or a connector has poor contact.
Common causes
Most likely first.
- Signal shorted to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Check-engine light on
- Possible reduced engine power or sluggish response
How to diagnose it
- Save freeze-frame data and check live valve B position feedback to confirm whether the signal is low or drops out when the fault occurs.
- Inspect the position-sensor wiring for chafing through insulation, especially near moving parts and the valve B connector.
- Check the connector seal and terminals for water, corrosion, loose fit, or a pushed-back pin.
- Wiggle the harness gently while monitoring live position data to see whether the low signal changes, taking care to avoid moving parts.
- Test the signal wire for a short to ground and check the sensor supply, ground, and signal circuit against the manufacturer’s specification.
Common fixes
- Repair chafed wiring shorted to ground in the valve B position-sensor circuit.
- Dry and repair a water-damaged connector or replace damaged terminals and seals.
- Reseat a pushed-back pin and secure the connector.
- Replace the valve B position sensor if its output remains below specification with sound wiring.
Can I keep driving?
Reduced power or sluggish response may occur if the module cannot read valve B’s position. Avoid heavy loads and high-speed driving until the low signal is repaired.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.