P226D — DPF Differential Pressure Sensor Circuit
P226D is a circuit fault on the DPF differential pressure sensor. Hose inspection first prevents unnecessary sensor replacement — clogged DP hoses are more common than failed sensors. Always clean or replace hoses when servicing the sensor.
Fault Overview
Failed sensor, clogged hoses or ports, wiring open or short, and connector issues are the primary causes. Route hoses correctly to avoid condensation traps. Clogged DP hoses are more common than failed sensors.
Engine & Platform Coverage
Symptoms
- •P226D
- •DPF pressure sensor circuit
- •DP sensor code
- •differential pressure sensor fault
Possible Causes
- 1.Failed sensor
- 2.Clogged hoses or ports
- 3.Wiring open or short
- 4.Connector issues
Wiring & Circuit Notes
DP sensor connector and signal circuits.
DVOM Specs & Sensor Tests
Sensor voltage at key-on (should be low, near 0.5 V). Response when hoses are manipulated. Hose condition and flow.
Diagnostic Flow — FSM Sequence
AI Diesel Tech enforces this evidence-gate sequence. Each gate must pass before advancing.
3 steps locked behind Technician Mode- 1Step 1 — Inspect and Clean DP Hoses and Ports: Inspect and clean the DP sensor hoses and sampling ports. Clogged hoses are the most common cause.
- 2Step 2 — Measure Sensor Voltage and Response: Measure sensor voltage at key-on and verify it responds when hoses are manipulated.
- 3Step 3 — Check Wiring: Check wiring for opens or shorts.
- 4Step 4 — Replace Sensor if Circuit and Hoses Are Good: Replace the DP sensor only if the circuit and hoses are proven good.
Unlock the full evidence-gated diagnostic sequence, DVOM test steps, and repair procedures in Technician Mode.
Full Diagnostic Access
Verification steps, preventative measures, severity guidance, and legacy comparison are available in Technician Mode.
Typical Repair Costs
Clean hoses and ports $30–100; replace sensor $80–300.
Start Diagnosing This Fault Now
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Summary
Use the AI Diesel Tech diagnostic engine to run this code through a structured, evidence-gated sequence and get a confirmed root cause before any parts are replaced.