DEF Dosing Quantity Collection Test Standard
Perform the DEF dosing quantity collection test only after pressure is confirmed and crystallization is cleaned. Replace the valve only if the measured volume is out of specification.
Fault Overview
System process standard for performing a quantitative DEF dosing collection test to measure actual injected volume against commanded volume. Used to confirm under- or over-dosing when pressure and circuit checks are normal.
Engine & Platform Coverage
Symptoms
- •DEF quantity collection test
- •Doser volume test
- •DEF injection quantity measurement
- •Dosing performance test
Possible Causes
- 1.N/A — process. Used to confirm under- or over-dosing when pressure and circuit checks are normal.
Wiring & Circuit Notes
Confirm dosing valve and pump circuits are electrically sound before relying on collection results.
DVOM Specs & Sensor Tests
Follow OEM procedure exactly (temperature, pressure, command duration). Collect DEF in a graduated container from the dosing valve outlet or test port. Compare collected volume to commanded quantity. Tolerance is platform-specific.
Diagnostic Flow — FSM Sequence
AI Diesel Tech enforces this evidence-gate sequence. Each gate must pass before advancing.
6 steps locked behind Technician Mode- 1Step 1 — Verify DEF Pressure and Pump Performance: Verify DEF pressure and pump performance are within specification. Collection results are only valid when upstream pressure is correct.
- 2Step 2 — Clean Dosing Valve and Nozzle of All Crystals: Clean dosing valve and nozzle of all crystals. Restriction from crystals will produce a false low-quantity result.
- 3Step 3 — Set Up Collection Equipment Per OEM Instructions: Set up collection equipment per OEM instructions. Follow OEM procedure exactly (temperature, pressure, command duration).
- 4Step 4 — Run the Service Dosing Routine or Commanded Pulse Sequence: Run the service dosing routine or commanded pulse sequence per OEM procedure.
- 5Step 5 — Measure Collected Volume and Compare to Specification: Measure collected volume and compare to specification. Tolerance is platform-specific.
- 6Step 6 — If Low, Recheck for Restriction or Replace Valve: If low, recheck for restriction or replace valve. If high, check for leakage or stuck-open condition.
- 7Step 7 — Retest After Repair: Retest after repair to confirm quantity is within specification.
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 or replace dosing valve/nozzle based on quantitative result; correct upstream pressure if needed. Cost varies by finding.
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Summary
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