Circuit/System Testing
WARNING: This page is about a different variant/trim than selected.
- Ignition/Vehicle - Off
- Verify the following conditions do not exist: Blade @ Q38 Throttle Body
- Binding or Sticking @ Open/Close - Position
- Closed @ Engine Off
- Coking/Debris / Dirty / Visible Damage
- Open/Close - Without spring pressure
- Water intrusion - Ice
WARNING:Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury.
- If a condition exists
Test or replace the component: Q38 Throttle Body
- Go to next step: If no condition exists
- Disconnect the electrical connector: Q38 Throttle Body
- Ignition - On / Vehicle - In Service Mode
- Test for 8 to 9 V between the test points:
- Control circuit terminal 1 @ & Ground
- Control circuit terminal 2 @ & Ground
- If less than 8 V
- Ignition/Vehicle - Off
- Disconnect the appropriate electrical connector: K20 Engine Control Module
- Test for infinite resistance between the test points:
- Control circuit terminal 1 @ Component harness & Ground
- Control 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
- Test for infinite resistance between the test points: Control circuit terminal 1 & Control circuit terminal 2 @ Component harness
- If less than infinite resistance - Repair the short between the circuits.
- Go to next step: If infinite resistance
- Test for less than 2 ohms between the test points:
- Control circuit terminal 1 @ Component harness & The other end of the circuit @ Control module harness
- Control 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
- If greater than 9 V
- Ignition/Vehicle - Off
- Disconnect the appropriate electrical connector: K20 Engine Control Module
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points:
- Control circuit terminal 1 @ Component harness & Ground
- Control 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 8 and 9 V
- Connect a test lamp between the test points: Control circuit terminal 1 & Control circuit terminal 2 @ Component harness
- Perform the scan tool control function: Diesel Intake Air Flow Control Valve - Increase & Decrease
- Verify the test lamp turns On and Off.
- If the test lamp does not turn On and Off
- Ignition/Vehicle - Off Remove - Test Lamp
- Disconnect the appropriate electrical connector: K20 Engine Control Module
- Test for less than 2 ohms between the test points:
- Control circuit terminal 1 @ Component harness & The other end of the circuit @ Control module harness
- Control 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 the test lamp turns On and Off
- Test or replace the component: Q38 Throttle Body
NOTE:
Disconnecting the component electrical connector causes additional DTCs to set.