Manufacturer Code Charts: 30
Adaptive Cruise Control (ACC) DTC Troubleshooting: 30
DTC 30:
Brake Light Relay Circuit Malfunction
1. Check the brake lights without pressing the brake pedal.
Are the brake lights off?
YES -
Go to step 11.
NO -
Go to step 2.
2. Check the brake pedal height, and adjust it if needed Adjustments.
3. Check the brake lights without pressing the brake pedal.
Are the brake lights off?
YES -
Intermittent failure, the system is OK at this time. Check for loose or poor connections.�
NO -
Go to step 4.
4. Test the brake pedal position switch Testing and Inspection.
Is the brake pedal position switch OK?
YES -
Go to step 5.
NO -
Adjust or replace the brake pedal position switch, and recheck Adjustments.�
5. Test the brake light relay Testing and Inspection.
Is the relay OK?
YES -
Go to step 6.
NO -
Replace the relay, and recheck.�
6. Disconnect the brake pedal position switch 4P connector.
7. Measure the voltage between brake pedal position switch 4P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Repair a short to power in the wire between the brake pedal position switch and the brake light relay.�
NO -
Go to step 8.
8. Disconnect the ACC unit 20P connector.
9. Disconnect each taillight 4P connector and the high mount brake light 2P connector.
10. Measure the voltage between ACC unit 20P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
Repair a short to power in the wire between the ACC unit and the brake light relay, or between the ACC unit and the brake lights circuits.�
NO -
Check for loose or poor connections. If OK, update the ACC unit Programming and Relearning, then recheck. If the ACC unit was already updated, replace the ACC unit Service and Repair.�
11. Clear the DTCs with the HDS.
12. Press the MAIN switch ON.
13. Check the brake lights with the brake pedal pressed.
Do the brake lights come on?
YES -
Go to step 14.
NO -
Go to step 38.
14. Check for DTCs with the HDS.
Is DTC 30 indicated?
YES -
Go to step 15.
NO -
Go to step 22.
15. Press the engine start/stop button to select the OFF mode.
16. Remove the brake light relay.
17. Disconnect the VSA modulator-control unit 46P connector Service and Repair.
18. Disconnect the ACC unit 20P connector.
19. Disconnect each taillight 4P connector and the high mount brake light 2P connector.
20. Measure the resistance between ACC unit 20P connector terminal No. 1 and body ground. There should be an open circuit or at least 1 MOhms.
Is the resistance as specified?
YES -
Go to step 21.
NO -
Repair a short to ground in the wire between the ACC unit and the brake light relay, or between the ACC unit and the brake lights circuits.�
21. Measure the resistance between ACC unit 20P connector terminal No. 1 and brake light relay 5P connector terminal No. 1. There should be less than 1.0 Ohms.
Is the resistance as specified?
YES -
Check for loose or poor connections. If OK, update the ACC unit Programming and Relearning, then recheck. If the ACC unit was already updated, replace the ACC unit Service and Repair.�
NO -
Repair an open in the wire between the ACC unit and the brake light relay.�
22. Test the brake light relay Testing and Inspection.
Is the relay OK?
YES -
Go to step 23.
NO -
Replace the relay, and recheck.�
23. Remove the brake light relay.
24. Measure the voltage between brake light relay 5P connector terminal No. 2 and body ground. There should be battery voltage.
Is there battery voltage?
YES -
Go to step 25.
NO -
Repair an open in the wire between the No. 10 (15 A) fuse in the under-hood fuse/relay box and the brake light relay.�
25. Press the engine start/stop button to select the ON mode.
26. Measure the voltage between brake light relay 5P connector terminal No. 5 and body ground. There should be battery voltage.
Is there battery voltage?
YES -
Go to step 27.
NO -
Repair an open in the wire between the No. 2 (7.5 A) fuse in the driver's under-dash fuse/relay box and the brake light relay.�
27. Press the engine start/stop button to select the OFF mode.
28. Disconnect the ACC unit 20P connector.
29. Measure the resistance between ACC unit 20P connector terminal No. 16 and body ground. There should be an open circuit or at least 1 MOhms.
Is the resistance as specified?
YES -
Go to step 30.
NO -
Repair a short to ground in the wire between the ACC unit and the brake light relay.�
30. Measure the resistance between ACC unit 20P connector terminal No. 16 and brake light relay 5P connector terminal No. 3. There should be less than 1.0 Ohms.
Is the resistance as specified?
YES -
Go to step 31.
NO -
Repair an open in the wire between the ACC unit and the brake light relay.�
31. Install the brake light relay.
32. Reconnect the ACC unit 20P connector.
33. Clear the DTCs with the HDS.
34. Press the engine start/stop button to select the ON mode, then wait for 10 seconds, and press the MAIN switch ON.
35. Select ADAPTIVE CRUISE CONTROL (ACC) from the DRIVING SUPPORT menu, then enter ACC RELAY from the FUNCTION TEST menu.
36. Do the brake light relay function test with the HDS.
37. Check for DTCs with the HDS.
Is DTC 30 indicated?
YES -
Check for loose or poor connections. If OK, update the ACC unit Programming and Relearning, then recheck. If the ACC unit was already updated, replace the ACC unit Service and Repair.�
NO -
Troubleshoot the indicated DTC(s). If there are no DTCs, the system is OK at this time.�
38. Check for DTCs with the HDS.
Is DTC 30 indicated?
YES -
Go to step 39.
NO -
Go to step 45.
39. Test the brake light relay Testing and Inspection.
Is the relay OK?
YES -
Go to step 40.
NO -
Replace the relay, and recheck.�
40. Remove the brake light relay.
41. Disconnect the ACC unit 20P connector.
42. Disconnect each taillight 4P connector and the high mount brake light 2P connector.
43. Measure the resistance between ACC unit 20P connector terminal No. 1 and body ground. There should be an open circuit or at least 1 MOhms.
Is the resistance as specified?
YES -
Go to step 44.
NO -
Repair a short to ground in the wire between the ACC unit and the brake light relay, or between the ACC unit and the brake lights circuits.�
44. Measure the resistance between ACC unit 20P connector terminal No. 1 and brake light relay 5P connector terminal No. 1. There should be less than 1.0 Ohms.
Is the resistance as specified?
YES -
Check for loose or poor connections. If OK, update the ACC unit Programming and Relearning, then recheck. If the ACC unit was already updated, replace the ACC unit Service and Repair.�
NO -
Repair an open in the wire between the ACC unit and the brake light relay.�
45. Check the brake pedal height, and adjust it if needed Adjustments.
46. Test the brake pedal position switch Testing and Inspection.
47. Check the brake lights with the brake pedal pressed.
Do the brake lights come on?
YES -
Intermittent failure, the system is OK at this time. Check for loose or poor connections.�
NO -
Repair an open in the wire or poor ground (G604, G652).�