Circuit/System Testing

NOTE:

Use the Wiring Schematics and connector end views to identify the control module's ground, B+, ignition, and serial data circuit terminals.

Ignition/Vehicle OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the harness connectors at the control module specified by the DTC descriptor. It may take up to 10 min for all vehicle systems to power down.
Test for less than 10 Ω between each ground circuit terminal and ground.
- If 10 Ω or greater
1. Ignition/Vehicle OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, repair the open/high resistance in the ground connection.
- Go to next step: If less than 10 Ω
Ignition ON/Vehicle In Service Mode.
If equipped, verify a test lamp illuminates between each B+ circuit terminal and ground.
- If the test lamp does not illuminate and the circuit fuse is good
1. Ignition/Vehicle OFF, remove the test lamp.
2. Test for less than 2 Ω in the B+ circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
1. Ignition/Vehicle OFF, remove the test lamp.
2. Test for infinite resistance between the B+ circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the control module specified by the DTC descriptor.
- Go to next step: If the test lamp illuminates
If equipped, verify a test lamp illuminates between each ignition circuit terminal and ground.
- If the test lamp does not illuminate and the circuit fuse is good
1. Ignition/Vehicle OFF, remove the test lamp.
2. Test for less than 2 Ω in the ignition circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, verify the fuse is OK and there is voltage at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
1. Ignition/Vehicle OFF, remove the test lamp.
2. Test for infinite resistance between the ignition circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the control module specified by the DTC descriptor.
- Go to next step: If the test lamp illuminates
If equipped, verify a test lamp illuminates between each ignition circuit terminal, which is controlled by a control module, and ground.
- If the test lamp does not illuminate
1. Ignition/Vehicle OFF, remove the test lamp, disconnect the harness connectors at the control module that controls the ignition circuit and all devices that share the same ignition circuit.
2. Test for infinite resistance between the ignition circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
3. Test for less than 2 Ω in the ignition circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - Go to next step: If less than 2 Ω
4. Reconnect the control module that controls the ignition circuit, ignition ON/Vehicle In Service Mode.
5. Verify a test lamp illuminates between the ignition circuit terminal and ground.
  - If the test lamp does not illuminate, replace the control module that controls the ignition circuit.
  - Go to next step: If the test lamp illuminates
6. Ignition/Vehicle OFF, reconnect the first device that shares the same ignition circuit, ignition ON/Vehicle In Service Mode.
7. Verify a test lamp illuminates between the ignition circuit terminal and ground.
  - If the test lamp does not illuminate, replace the device that was just connected.
  - If the test lamp illuminates and there are more devices to connect, connect the next device and repeat step 6.7 until there are no more devices to connect.
- Go to next step: If the test lamp illuminates
If equipped, verify a test lamp illuminates between the accessory wakeup serial data circuit terminal or the serial data communication enable circuit terminal and ground.
- If the test lamp does not illuminate
1. Ignition/Vehicle OFF, remove the test lamp, disconnect the harness connectors at the K9 Body Control Module.
2. Test for less than 2 Ω in the accessory wakeup serial data circuit or the serial data communication enable circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the K9 Body Control Module.
- Go to next step: If the test lamp illuminates
Ignition/Vehicle OFF, disconnect the harness connectors at the device setting the DTC.
Ignition ON/Vehicle In Service Mode.
Test for less than 4.5 V between each Ethernet serial data circuit terminal and ground.
- If 4.5 V or greater
  Repair the short to voltage in the serial data circuit.
- Go to next step: If less than 4.5 V
Ignition/Vehicle OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. It may take up to 10 min for all vehicle systems to power down.
Test for infinite resistance between each Ethernet serial data circuit terminal and ground.
- If less than infinite resistance
  Repair the short to ground in the serial data circuit.
- Go to next step: If infinite resistance
Test for infinite resistance between each pair of Ethernet serial data circuit terminals.
- If less than infinite resistance
  Repair the short together in the serial data circuits.
- Go to next step: If infinite resistance
Test for less than 2 Ω in each Ethernet serial data circuit end to end.
- If 2 Ω or greater
  Repair the open/high resistance in the serial data circuit.
- Go to next step: If less than 2 Ω
Replace the control module specified by the DTC descriptor.