Circuit/System Testing

NOTE:

Use the Wiring Schematics to identify the items listed below:
- Control modules the vehicle is equipped with
- The control module's B+, ignition, and ground circuits
- The control module's circuit terminals and connectors
Some control module ground circuits may require up to 20 min after the ignition is turned Off before achieving a resistance reading of less than 5 ohms. In most cases the readings will drop below 20 ohms within 1 min indicating the control modules are going to sleep.

Ignition/Vehicle & All vehicle systems - Off
Disconnect the electrical connector:K9 Body Control Module
Test for less than 10 ohms between the test points:Each ground circuit terminal & Ground
- If 10 ohms or greater
1. Disconnect the ground connection:Ground terminal
2. Test for less than 2 ohms between the test points:Ground circuit terminal @ Control module harness & The other end of the circuit
  - 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
Verify a test lamp turns On between the test points:Each B+ circuit terminal & Ground
- If the test lamp does not turn On and the circuit fuse is OK
1. Remove - Test Lamp
2. Test for less than 2 ohms between the test points:B+ circuit terminal @ Control module harness & Output terminal @ Fuse
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
- If the test lamp does not turn On and the circuit fuse is open
1. Remove - Test Lamp
2. Test for infinite resistance between the test points:B+ circuit terminal @ Control module harness & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - If infinite resistance - Replace the component:K9 Body Control Module
- Go to next step: If the test lamp turns On
Ignition - On / Vehicle - In Service Mode
Verify a test lamp turns On between the test points:Each ignition circuit terminal & Ground
- If the test lamp does not turn On and the circuit fuse is OK
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Test for less than 2 ohms between the test points:Ignition circuit terminal @ Control module harness & Output terminal @ Fuse
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
- If the test lamp does not turn On and the circuit fuse is open
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Test for infinite resistance between the test points:Ignition circuit terminal @ Control module harness & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - If infinite resistance - Replace the component:K9 Body Control Module
- Go to next step: If the test lamp turns On
Verify the DMM displays the following:Each B+ circuit terminal & Ground = Within 1 V of the battery voltage
- If not the specified value
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Test for less than 2 ohms between the test points:Each B+ circuit terminal @ Control module harness & Output terminal @ Fuse
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
- Go to next step: If the specified value
Verify the DMM displays the following:Each ignition circuit terminal & Ground = Within 1 V of the battery voltage
- If not the specified value
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Test for less than 2 ohms between the test points:Ignition circuit terminal @ Control module harness & Output terminal @ Fuse
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
- Go to next step: If the specified value
Replace the component:K9 Body Control Module