Default Strategies

After detecting a fault, Self Leveling and Anti-Lock Brake Electronic Control Module (SLABS ECU) selects a default strategy which, if possible, retains some operational capability. Shuttle valve switch fault and throttle position signal fault are considered permanent faults. If permanent fault is detected, the related warning light(s) will illuminate and appropriate default strategies will be employed in subsequent ignition cycles until fault is repaired and cleared from memory. For non-permanent faults, illumination of related warning light(s) and default strategies will be employed in subsequent ignition cycles only if fault is still present.

Default strategies are as follows:

• Brakelight relay fault - ABS, ETC, EBD and HDC are all enabled.
• Throttle position signal failure - ABS and EBD are enabled. ETC is disabled. HDC is immediately disabled if not in active braking mode or faded out then disabled if in active braking mode.
• Open or poor ground - ABS, ETC and HDC are disabled. EBD is partly disabled.
• Return pump or relay fault - ABS, ETC and HDC are disabled. EBD is partly disabled.
• Shuttle valve switch failure - ABS operation modified so deceleration threshold is increased. Return pump is activated if sum of output valve actuation on one axle exceeds 140 milliseconds. ETC and HDC are disabled. EBD operation modified so inlet valves of rear axle close at vehicle deceleration rates of 0.3 g or more.
• SLABS ECU internal failure - ABS, ETC, EBD and HDC are all disabled.
• Supply voltage out of limits - ABS, ETC, EBD and HDC are all disabled.

After ABS sensor fault is repaired, ABS and ETC functions remain disabled and ABS warning light remains illuminated after bulb check until vehicle speed exceeds 10 MPH.