Reading and Clearing Diagnostic Trouble Codes

To enter diagnostic mode, vehicle speed must be below 10 mph. If vehicle speed is above 10 mph, a "No Response" message will be displayed on the DRB II. The following are characteristics of diagnostic mode.

1. The amber anti-lock warning lamp and brake warning lamp will flash.
2. If a hard fault, such as an inlet or outlet valve fault or main relay/power circuit failure fault, is present, these lamps will illuminate without blinking and no diagnostic operations will be available until the fault condition is cleared.
3. Anti-lock and traction control operation are disabled.
4. You will be unable to actuate the valves in the valve body when the vehicle speed is above 5 mph.
5. If valve actuation is attempted above 5 mph, a "vehicle in motion" message will be displayed through the DRB II.
6. Refer to test 1A and 1B, under Diagnostic Charts for checking the system for faults, then proceed as indicated to the remaining diagnostic charts. After performing appropriate procedure, perform verification test to verify system operation.