Circuit/System Testing

Class 2 Communication Initial Test 

1. Test for less than 1 ohm between the DLC ground circuit terminal 5 and ground.
   • If greater than the specified range, test the ground circuit for open/high resistance.
2. Ignition OFF, disconnect the harness connector of JX305 and attempt to communicate with the BCM. Communication should not be available.
   • If communication is available, refer to JX305 Test below.
3. Ignition OFF, disconnect the harness connector of JX205.
4. Ignition ON, test for less than 1 volt between the serial data circuit terminal H of JX205 and ground.
   • If greater than the specified range, test the serial data circuit for a short to voltage.
5. Test for infinite resistance between the serial data circuit terminal H of JX205 and ground.
   • If less than the specified value, test the serial data circuit for a short to ground.
6. Ignition ON, test for less than 1 volt between the serial data circuit terminal A of JX205 and ground.
   • If greater than the specified range, test the serial data circuit for a short to voltage.
7. Test for infinite resistance between the serial data circuit terminal A of JX205 and ground.
   • If less than the specified value, test the serial data circuit for a short to ground.
8. Test for less than 1 ohm on the serial data circuit between terminal A of JX205 and terminal 2 of the DLC.
   • If greater than the specified range, test the serial data circuit for open/high resistance.
9. Ignition OFF, disconnect the harness connectors X1 and X3 of the BCM
10. Verify a test lamp illuminates between each ground circuit terminal of the BCM listed below and B+.
    • X3 - A11
    • X3 - B11
    • If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
11. Ignition ON, verify a test lamp illuminates between each voltage circuit terminal of the BCM listed below and ground.
    • X1 - A3
    • X1 - A19
    • X3 - A1
    • X3 - A2
    • X3 - A20
    • X3 - B4
    • X3 - B13
    • X3 - B15
    • X3 - B17
    • X3 - B18
    • If the test lamp does not illuminate, test the voltage circuit for an open/high resistance or short to ground.
12. Ignition OFF, connect the harness connectors of the BCM.
13. Ignition OFF, connect a 3-amp fused jumper wire between terminal A and terminal M of JX205. Attempt to communicate with the BCM. Communication should be available.
    • If communication is not available, test the serial data circuit for a short to voltage, or short to ground between the BCM and JX205. If the circuits test normal, replace the BCM.
IMPORTANT: After each connection, wait for 5 seconds to determine that communication remains available.
14. Connect another 3-amp fused jumper wire to terminal A of JX205. Individually connect the other end of the jumper wire to each other terminal of JX205 and verify that communication remains available to the BCM.
    • If communication is interrupted, test the serial data circuit between JX205 and the last module connected for a short to ground or a short to voltage. If the circuit tests normal, replace the module that caused no communication.