ATTENTION: SUBJECT: SERVICE MANAGERS / PARTS MANAGERS INTERMITTENT SHUTDOWN OF CUMMINS ENGINE AND VARIOUS FAULT CODES ON CERTAIN WX AND WXLL TRUCKS EQUIPPED WITH CUMMINS ENGINES Service Bulletin Information: Service Bulletins are product modifications and/or product improvements that Autocar has determined will enhance the operation of the truck. This bulletin provides information on a solution that should provide a solution for the following problems experienced on trucks fitted with Cummins engines: 1. Intermittent engine shutdowns on the truck that might or might not be accompanied by the following: 2. Cummins Fault Code 434 or 3. A.B.S. Light on or 4. Communication error or 5. Shutdown with no codes at all The cause has been determined as a compromised connection at the pass-through ground terminal under the left-hand side of the cab. Repair: See the Repair Procedure on Page 2. Parts: No parts are required for this repair. 1 of 9
Repair Procedure WARNING To prevent eye injury, always wear eye protection when performing vehicle maintenance, service or inspection. WARNING Turn and lock the battery disconnect switch to disconnect the battery power to the truck to limit the risk of electrical shock and fire. DANGER Before working on a vehicle, set the parking brake, place the transmission in neutral and block the wheels. Failure to do so can result in unexpected vehicle movement and can cause serious personal injury or death. 2 of 9
1. Park the vehicle on a level surface. Turn off the engine, apply the parking brakes, and chock the rear tires to keep the vehicle from moving. 2. Tilt the cab forward. See the instructions beginning on page 6 for instructions in raising and lowering the cab. 3. With the cab tilted forward, locate the pass-through connector under the left-hand foot well on the outside of the cab as shown in Figure 1. COVER ON PASS- THROUGH CONNECTOR Figure 1 3 of 9
4. Remove the cover (Figure 2) and the ground terminals (Figure 3). Figure 2 REMOVE TERMINALS REMOVE TERMINALS Figure 3 4 of 9
5. Inspect and clean the ground terminals. Secure the ground terminals in position taking care to ensure the terminals seat properly and the nut on the terminal is securely tightened. (Figure 4). TIGHTEN SECURELY Figure 4 6. The installation is complete. Lower cab as per the instructions beginning on page 6. 7. Once the cab is lowered and locked in position start the engine to verify that the problem has been resolved. 5 of 9
Tilting Cab General NOTE: Remove or secure all loose articles and close all doors before tilting the cab. The area above and ahead of the cab must be clear. The front wheels should be pointed in the straight ahead position. Read the label affixed to the seat base for more cab tilting information. DANGER Before working on a vehicle, set the parking brake, place the transmission in neutral and block the wheels. Failure to do so can result in unexpected vehicle movement and can cause serious personal injury or death. CAUTION Before working on a vehicle, set the parking brake, place the transmission in neutral and block the wheels. Failure to do so can result in unexpected vehicle movement and can cause serious personal injury or death. 6 of 9
Raising the Cab Release the cab latch by lifting the security lock (1) on the lever and then push lever (2) up until the cab latch hook (3) is free from its retainer. The cab lock is now in its open position (B). Release the cab latch on the other side of the cab. WARNING Disengage both cab latches before tilting the cab. Raising the cab with only one latch disengaged can result in vehicle damage. Remove the pump handle from its storage location on either the driver or passenger side rear cab corner. It is held in place with two clips to the cab wall. Place the flow valve selector on the cab tilt pump pointing rearward. The text on the selector handle that reads RAISE is now facing out. Put one end of the pump handle into the pump and operate the pump in an up and down motion. As hydraulic pressure increases, the cab tilt cylinders will start to move the cab up. When the cab goes over its balance point, it will fall at a controlled speed to its full tilt position and automatically relieves the hydraulic system pressure. 7 of 9
To stop the cab in a partially tilted position while raising it, stop pumping and place the flow valve selector in the hold position. Install the lock pin in the cab tilt lock tube wherever the holes line up. DANGER Do not rely on the hydraulic pressure to hold the cab in a partially open position. Always use the lock pin in the cab tilt lock tube to prevent personal injury or death. 8 of 9
Lowering the Cab Place the flow valve selector on the cab tilt pump pointing forward. The text on the selector handle that reads LOWER is now facing out. Remove the lock pin from the cab tilt lock tube. Put one end of the pump handle into the pump and operate the pump in an up and down motion. As hydraulic pressure increases, the cab tilt cylinders will start to move the cab. When the cab goes over its balance point, it will fall at a controlled speed until it settles over the rear mounts. Remove the pump handle from the pump and return it to its storage location inside the cab. Locking the Cab in Place The hold down latch hook (3) is placed into the retainer and then locked down by pulling the latch lever (2) down. Make sure the security lock (1) snaps into place to hold the latch lever in place. Lock the cab latch on the other side of the cab. 9 of 9