Circuit/System Testing

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

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: M122 Exhaust Pressure Regulator Valve
Test for less than 10 ohms between the test points: Low Reference circuit terminal 1 & Ground
- If 10 ohms or greater
1. Disconnect the electrical connector: X2@K20 Engine Control Module
2. Test for less than 2 ohms between the test points: Low Reference circuit terminal 1@Component harness & The other end of the circuit@Control module harness
  - 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 10 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 & Low Reference circuit terminal 1
- If less than 4.8 V
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: X1@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@Control module harness
  - 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: X1@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 3@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
Test for 4.7 to 5.3 V between the test points: Serial Data circuit terminal 2 & Ground
- If less than 4.7 V
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: X1@K20 Engine Control Module
3. Test for infinite resistance between the test points: Serial Data circuit terminal 2@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 infinite resistance between the test points: Serial Data circuit terminal 2@Component harness & Low Reference circuit terminal 1@Component harness
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
5. Test for less than 2 ohms between the test points: Serial Data circuit terminal 2@Component harness & The other end of the circuit@Control module harness
  - 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 greater than 5.3 V
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector: X1@K20 Engine Control Module
3. Ignition - On/Vehicle - In Service Mode
4. Test for less than 1 V between the test points: Serial Data circuit terminal 2@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 4.7 and 5.3 V
Test or replace the component: M122 Exhaust Pressure Regulator Valve