Circuit/System Testing

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

Verify no other DTCs are set.
- If any of the DTCs are set
  Refer to: Diagnostic Trouble Code (DTC) List - Vehicle
- Go to next step: If none of the DTCs are set
Verify the conditions listed in the table do not exist:
- B74 Manifold Absolute Pressure Sensor - Leaking @O-Ring - Missing / Visible Damage
- B75C Multifunction Intake Air Sensor - Contamination of the measuring element /Cracked/Loose Clamps / Visible Damage/Water intrusion
- B111B Turbocharger Boost/Intake Air Temperature Sensor
  - Leaking @ O-Ring - Missing / Visible Damage
  - Restricted - Moisture/Ice
  - Skewed
- Q38 Throttle Body
  - Coking/Loose Clamps /Visible Damage
  - Restricted - Moisture/Ice
- Air Cleaner Element - Dirty / Restricted
- Catalytic Converter - Blocked / Restricted/Visible Damage
- Charge Air Cooler
  - Leaking / Incorrect connection
  - Restricted - Moisture/Ice
- Engine - Mechanical Condition - Refer to: Symptoms - Engine Mechanical
- Exhaust System - Leaking /Restricted/ Visible Damage - Refer to: Symptoms - Engine Exhaust
- Intake Air Duct - Cracked / Loose Clamps / Restricted / Visible Damage
- Intake Manifold - Cracked / Loose Clamps / Restricted / Vacuum leak/Visible Damage
- Linkage@Turbocharger Wastegate Actuator - Binding or Sticking/Loose/Visible Damage
- Positive Crankcase Ventilation System
  - Leaking @ O-Ring - Missing / Visible Damage
  - Restricted - Moisture/Ice
  - Incorrect connection /Leaking / Restricted
- Vacuum Hoses - Kinked / Leaking / Incorrect connection / Restricted
- Vacuum leak @ Engine - Oil Level Indicator and Tube /Oil Filler Cap
- If a condition exists
  Repair as necessary
- Go to next step: If no conditions exist

NOTE:

It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

Ignition/Vehicle & All vehicle systems - Off
Disconnect the electrical connector: B111B Turbocharger Boost/Intake Air Temperature Sensor. It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.
Test for less than 5 ohms between the test points: Low Reference circuit terminal 1 & Ground
- If 5 ohms or greater
1. Disconnect the electrical connector: X3@K20 Engine Control Module
2. Test for less than 2 ohms between the test points: Low Reference circuit terminal 2@Component harness & The other end of the circuit
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: K20 Engine Control Module
- Go to next step: If less than 5 ohms
Ignition - On / Vehicle - In Service Mode
Test for 4. 8 to 5. 2 V between the test points: 5 V Reference circuit terminal 3 & Ground
- If less than 4. 8 V
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: X3@K20 Engine Control Module
3. Test for infinite resistance between the test points: 5 V Reference circuit terminal 3@Component harness & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
4. Test for less than 2 ohms between the test points: 5 V Reference circuit terminal 3@Component harness & The other end of the circuit
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: K20 Engine Control Module
- If greater than 5. 2 V
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: K20 Engine Control Module
3. Ignition - On / Vehicle - In Service Mode
4. Test for less than 1 V between the test points: 5 V Reference circuit terminal 1@Component harness & Ground
  - If 1 V or greater - Repair the short to voltage on the circuit.
  - If less than 1 V - Replace the component: K20 Engine Control Module
- Go to next step: If between 4. 8 and 5. 2 V
Verify the scan tool parameter: Boost Pressure Sensor = Greater than 4. 7 V
- If 4. 7 V or less
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: Signal circuit terminal 4@Component harness & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - If infinite resistance - Replace the component: K20 Engine Control Module
- Go to next step: If greater than 4. 7 V
Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 4 & Low Reference circuit terminal 1
Verify the scan tool parameter: Boost Pressure Sensor = Less than 0. 2 V
- If 0. 2 V or greater
1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
2. Disconnect the electrical connector: K20 Engine Control Module
3. Ignition - On / Vehicle - In Service Mode
4. Test for less than 1 V between the test points: Signal circuit terminal 4@Component harness & Ground
  - If 1 V or greater - Repair the short to voltage on the circuit.
  - Go to next step: If less than 1 V
5. Ignition/Vehicle - Off
6. Test for less than 2 ohms between the test points: Signal circuit terminal 4@Component harness & The other end of the circuit
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: K20 Engine Control Module
- Go to next step: If less than 0. 2 V
Test or replace the component: B111B Turbocharger Boost/Intake Air Temperature Sensor