Circuit/System Testing

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

Ignition/Vehicle - Off
Disconnect the electrical connector: M122 Exhaust Pressure Control Valve Actuator
Ignition - On/Vehicle - In Service Mode
Test for 8 to 10 V between the test points:
- Control circuit terminal 4 & Ground
- Control circuit terminal 5 & Ground
- If less than 8 V
1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points:
  - Control circuit terminal 4@Component harness & Ground
  - Control circuit terminal 5@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: Control circuit terminal 4 & Control circuit terminal 5@Component harness
  - If less than infinite resistance - Repair the short between the circuits.
  - Go to next step: If infinite resistance
5. Test for less than 2 ohms between the test points:
  - Control circuit terminal 4 @ Component harness & The other end of the circuit @ Control module harness
  - Control circuit terminal 5 @ 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 10 V
1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Ignition - On/Vehicle - In Service Mode
4. Test for less than 1 V between the test points:
  - Control circuit terminal 4@Component harness & Ground
  - Control circuit terminal 5@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 8 and 10 V
Connect a test lamp between the test points: Control circuit terminal 4 & Control circuit terminal 5
Perform the scan tool control function: Exhaust Pressure Regulator Valve - Command the component to the maximum position/speed
Verify the test lamp turns On.
- If the test lamp does not turn On
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for less than 2 ohms between the test points:
  - Control circuit terminal 4 @ Component harness & The other end of the circuit @ Control module harness
  - Control circuit terminal 5 @ 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 the test lamp turns On
Test or replace the component: M122 Exhaust Pressure Control Valve Actuator