Circuit/System Testing
Test 1
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: S126 Drive Mode Select Switch
- Test for less than 10 ohms between the test points: Ground circuit terminal 5 & Ground
- If 10 ohms or greater
- Test for less than 2 ohms between the test points: Ground circuit terminal @ Component harness & Ground terminal
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Repair the open/high resistance in the ground connection.
- 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 9 & Ground
- If less than 4.8 V
- Ignition/Vehicle - Off
- Disconnect the electrical connector: K20 Engine Control Module
- Test for infinite resistance between the test points: 5 V Reference circuit terminal @ 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 less than 2 ohms between the test points: 5 V Reference circuit terminal @ 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
- Ignition/Vehicle - Off
- Disconnect the electrical connector: K20 Engine Control Module
- Ignition - On/Vehicle - In Service Mode
- Test for less than 1 V between the test points: 5 V Reference circuit terminal @ 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 less than 1 V between the test points: Signal circuit terminal 7 & Ground
- If 1 V or greater
- Ignition/Vehicle - Off
- Disconnect the electrical connector: K20 Engine Control Module
- Ignition - On/Vehicle - In Service Mode
- Test for less than 1 V between the test points: Signal circuit terminal @ 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 less than 1 V
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: K20 Engine Control Module
- Test for infinite resistance between the test points: Signal circuit terminal 7 @ Component harness & Ground
- If less than infinite resistance
Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- If less than infinite resistance
- Test for less than 2 ohms between the test points: Signal circuit terminal 7 @ Component harness & The other end of the circuit @ Control module harness
- If less than infinite resistance
Repair the open/high resistance in the circuit.
- Go to next step: If infinite resistance
- If less than infinite resistance
- Test or replace the component: S126 Drive Mode Select Switch
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set.
- If the DTC sets
Replace the component: K20 Engine Control Module
- Go to next step: If the DTC is not set
- If the DTC sets
- All OK.
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.
Test 2
- Ignition - On/Vehicle - In Service Mode
- Headlamp Switch = On
- Verify a test lamp turns On between the test points: Control circuit terminal 8 & Ground
- If the test lamp does not turn On
Refer to: Interior Backlighting Malfunction
- Go to next step: If the test lamp turns On
- If the test lamp does not turn On
- Ignition/Vehicle - Off & Remove - Test lamp
- Connect the electrical connector: S126 Drive Mode Select Switch
- Disconnect the electrical connector: X2 & X5 @ K9 Body Control Module
- Ignition - On/Vehicle - In Service Mode
- Test for less than 1 V between the test points:
- Signal circuit terminal 10 X5 & Ground
- Signal circuit terminal 21 X5 & Ground
- {With V92} Signal circuit terminal 23 X5 & Ground
- {With F48} Signal circuit terminal 6 X2 & Ground
- If 1 V or greater
- Disconnect the electrical connector: S126 Drive Mode Select Switch
- Test for less than 1 V between the test points:
- Signal circuit terminal 10 X5 & Ground
- Signal circuit terminal 21 X5 & Ground
- {With V92} Signal circuit terminal 23 X5 & Ground
- {With F48} Signal circuit terminal 6 X2 & Ground
- If 1 V or greater - Repair the short to voltage on the circuit.
- If less than 1 V - Replace the component: S126 Drive Mode Select Switch
- Go to next step: If less than 1 V
- Ignition/Vehicle - Off
- Test for infinite resistance between the test points:
- Signal circuit terminal 10 X5 & Ground
- Signal circuit terminal 21 X5 & Ground
- {With V92} Signal circuit terminal 23 X5 & Ground
- {With F48} Signal circuit terminal 6 X2 & Ground
- If less than infinite resistance
- Disconnect the electrical connector: S126 Drive Mode Select Switch
- Test for infinite resistance between the test points:
- Signal circuit terminal 10 X5 & Ground
- Signal circuit terminal 21 X5 & Ground
- {With V92} Signal circuit terminal 23 X5 & Ground
- {With F48} Signal circuit terminal 6 X2 & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- If infinite resistance - Replace the component: S126 Drive Mode Select Switch
- Go to next step: If infinite resistance
- Connect a 3 A fused jumper wire between each of the following circuit pairs, one at a time:
- Signal circuit terminal 10 X5 & Ground
- Signal circuit terminal 21 X5 & Ground
- {With V92} Signal circuit terminal 23 X5 & Ground
- {With F48} Signal circuit terminal 6 X2 & Ground
- Verify the component works as specified: Drive Mode - LED (Light Emitting Diode) @ S126 Drive Mode Select Switch = On
- If the component does not work as specified
- Disconnect the electrical connector: S48E Multifunction Switch - Center Console
- Ignition/Vehicle - Off
- Test for less than 2 ohms between the test points:
- Signal circuit terminal 10 X5 & Ground
- Signal circuit terminal 21 X5 & Ground
- {With V92} Signal circuit terminal 23 X5 & Ground
- {With F48} Signal circuit terminal 6 X2 & Ground
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Replace the component: S48E Multifunction Switch - Center Console
- Go to next step: If the component works as specified
- Replace the component: K9 Body Control Module