Circuit/System Testing

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

Ignition/Vehicle - Off
Disconnect the electrical connector: M122 Exhaust Pressure Regulator Valve
Connect a test lamp between the test points: Control circuit terminal 4 @ Component harness & Control circuit terminal 5
Ignition - On / Vehicle - In Service Mode
Perform the scan tool control function: Exhaust Pressure Regulator Valve
Verify the test lamp state:

Exhaust Pressure Regulator Valve - Release Control = Test lamp Off

Exhaust Pressure Regulator Valve - Increase = Test lamp On

Exhaust Pressure Regulator Valve - Decrease = Test lamp On
- If not the specified state
1. Ignition/Vehicle - Off & Remove - Test lamp
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:
  - 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.
  - Go to next step: If less than 1 V
5. Ignition/Vehicle - Off
6. 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
7. 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 specified state
Test or replace the component: M122 Exhaust Pressure Regulator Valve