Paccar Kenworth T800 2012, Manual, Page: 18 / 276

2-6
Section 2
Safety & Compliance
08/12
• See owner’s manual for appropriate winter front usage
Electrical System
The following are highlights of some of the more common or critical aspects of this system.
• Electrical harnesses providing battery power and electronic control signals to engine and emissions control/
vehicle OBD components including datalinks may not be spliced. These emissions control/vehicle OBD
components include the following:
• throttle pedal
• vehicle speed sensor
• after-treatment wiring
• If the alternator or battery is substituted, it must meet the requirements of the engine manufacture’s guide-
lines. This includes alternator ground voltage drop and alternator ground cable effectiveness. See the engine
manufacture’s guidelines for recommended test procedure. Additionally the maximum voltage differential and
the peak-peak voltage differential between the engine ECM block ground stud and battery negative terminal
may not exceed 500 mV under any combination of loads or operating conditions.
• Installation of aftermarket transfer-cases must address the vehicle speed sensor position. The standard posi-
tion of the speed sensor is at the transmission tail shaft. When a transfer-case is added it is best to relocate
the sensor to the axle side output shaft of the transfer-case. This is typically accomplished by adding a tone
wheel into the driveline yoke assembly.
• Wiring extensions for the after-treatment wiring are available for relocating the DEF tank from your dealer via
Paccar Parts. For relocation of DEF tank, refer to the after-treatment section of this manual.
• The emission system requires an accurate Outside Air Temperature (OAT) reading in order to properly run
its control algorithms. The OAT sensor is located in the driver’s side mirror assembly on Kenworth trucks and
is shown in the figures below. If the body builder needs to modify the mirror assembly in any way, it is im -
portant the OAT sensor stay positioned on the mirror assembly. Running the vehicle without the OAT sensor
connected will cause the MIL lamp to illuminate. If needed, a replacement sensor can be ordered from your
Kenworth dealer.
FIGURE 2-3:
West Coast Mirror OAT sensor, located in overmold on mirror harness.