Pierce Custom Chassis — 04V567000
Summary
ON CERTAIN FIRE TRUCKS EQUIPPED WITH THE ALL WHEEL STEER OPTION, THE POSITION OF THE FRONT AXLE IS SENSED BY AN OPTICAL ENCODER MOUNTED TO THE BOTTOM OF THE FRONT AXLE KINGPIN, WHICH IS PROTECTED FROM THE ELEMENTS BY AN OUTER CASE. THIS CASE SHARES A COMMON GREASE CAVITY WITH THE KINGPIN. OIL THAT LEACHES FROM THE GREASE CAN MIGRATE THROUGH THE ENCODER SEAL, CAUSING CONTAMINATION OF THE OPTICAL ENCODER DISC.
Consequence
OIL ON THE DISC CAN CAUSE THE ENCODER TO SEND INCORRECT WHEEL POSITION INFORMATION AND CAN CAUSE THE REAR WHEELS TO STEER UNEXPECTEDLY CAUSING THE VEHICLE TO CRASH WITHOUT PRIOR WARNING.
Remedy
DEALERS WILL REPLACE THE ENCODERS WITH NEW ENCODERS WITH MORE ROBUST SEALS. THE CONTROL SOFTWARE WILL BE UPDATED TO PRODUCE AN ERROR CODE AND DISABLE THE REAR STEERING FUNCTION IF UNUSUAL ENCODER INPUTS ARE DETECTED. THE RECALL BEGAN JANUARY 25, 2005. OWNERS SHOULD CONTACT PIERCE AT 1-888-974-3723.