Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.

Ignition - On / Vehicle - In Service Mode
Verify the scan tool parameter : MAF Sensor = 5 to 40 g/s
- If not between 5 and 40 g/s
  Verify the following conditions do not exist :
1. Intake Manifold - Leaking
2. Intake Air Duct - Loose Clamps/Cracked/Visible Damage
3. Mass Airflow Sensor - Contamination of the measuring element/Water intrusion
  - If a condition exists
    Repair or replace as necessary
  - If no condition exists
    Refer to : Diesel Particulate Filter (DPF) Service Regeneration
- Go to next step : If between 5 and 40 g/s
Ignition/Vehicle - Off
Verify a condition does not exist with the component :
- Exhaust System - Leaking/Missing components/Restricted - Refer to : Symptoms - Engine Exhaust
- Fuel - Contaminated/Poor Quality - Refer to : Contaminants-in-Fuel Diagnosis , & Fuel System Specifications
- Q17 Fuel Injector - Leaking/Restricted - Refer to : Fuel Injector Balance Test - Circuit/System Testing
- If a condition exists
  Repair or replace as necessary
- Go to next step : If no condition exists
Perform a conventional engine compression test. Refer to : Engine Compression Test
- If one or more cylinders indicate low compression
  Refer to : Symptoms - Engine Mechanical
- Go to next step : If all cylinders indicate normal compression
Replace the component : B195A Nitrogen Oxides Sensor 1