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If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
2. If you are in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving — DRIVE (D).
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can
drive normally.
If the warning continues and you have not stopped, pull
over, stop, and park your vehicle right away.
If there is still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you are parked. If you still have the warning,turn off the
engine and get everyone out of the vehicleuntil it
cools down. Also, see “Overheated Engine Protection
Operating Mode” later in this section.
You may decide not to lift the hood but to get service
help right away.Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil and
reset the oil life system. SeeEngine Oil on
page 5-13.
5-28
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Fuses Usage
DRIVER UNLOCKPower Door Lock
Relay (Driver’s Door
Unlock Function)
IGN 0Brake Transmission Shift
Interlock, Powertrain Control
Module, Transmission
TBC IGN 0 Truck Body Controller
VEH CHMSLVehicle and Trailer High
Mounted Stoplamp
LT TRLR ST/TRN Left Turn Signal/Stop Trailer
LT TRNLeft Turn Signals and
Sidemarkers
VEH STOPVehicle Stoplamps, Brake
Module, Electronic Throttle
Control Module
RT TRLR ST/TRN Right Turn Signal/Stop Trailer
RT TRNRight Turn Signals and
SidemarkersFuses Usage
BODY Harness Connector
DDM Driver Door Module
LOCKSRear Doors and Liftgate
Power Lock Relay Feed
ECC Liftgate
TBC 2C Truck Body Controller
FLASH Flasher Module
CB LT DOORSLeft Rear Power Window
Circuit Breaker and Driver
Door Module
TBC 2B Truck Body Controller
TBC 2A Truck Body Controller
Circuit Breaker Usage
AUX PWR 2 Midgate Controller (SUT Only)
5-105
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Center Instrument Panel Fuse Block
The center instrument panel utility block is located
underneath the instrument panel, to the left of the
steering column.
Device Usage
SEOSpecial Equipment
Option/Off-road Lamps
Harness Connector
TRAILER Trailer Brake Wiring
UPFIT Up tter (Not Used)
SL RIDE Ride Control (Not Used)
HDLR 2 Headliner Wiring Connector 2
BODY Body Wiring Connector
DEFOG Rear Defogger Relay
HDLNR 1 Headliner Wiring Connector 1
SPARE RELAY Not Used
CB SEATDriver and Passenger Seat
Module Circuit Breaker
CB RT DOORRear Right Power Window,
Passenger Door Module
SPARE Not Used
INFO Not Used
5-106
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Fuses Usage
GLOW PLUG Not Used
CUST FEED Gasoline Accessory Power
HYBRID Hybrid
STUD #1Accessory Power/Trailer
Wiring
MBEC 1Mid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBEC 2Left Bussed Electrical
Center, Door Modules, Door
Locks, Auxiliary Power
Outlet—Rear Cargo Area
and Instrument Panel
STUD #2Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-Lock Brakes
VSES/ECASElectronically Controlled Air
Suspension
IGN A Ignition Switch
IGN B Ignition SwitchFuses Usage
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STRTR Starter Relay
INTPARK Roof Marker Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller
Battery Feed
S/ROOF Sunroof
SEO B2 Off-Road Lamps
4WS Vent Solenoid Canister
RR HVAC Not Used
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Fuses Usage
AUX PWRInstrument Panel Outlets,
Rear Cargo Area Power
Outlets, Console
IGN 1 PCM Ignition
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
INJ 1Ignition Coil, Fuel
Injectors-Bank 1
INJ 2Ignition Coil, Fuel
Injectors-Bank 2
IGN EInstrument Panel Cluster, Air
Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay, Electronic Brake
Controller TC2 Mode Switch
RTDElectronic Brake Controller
Battery Feed
TRL B/U Backup Lamps Trailer Wiring
PCM BPowertrain Control Module,
Fuel Pump
F/PMP Fuel Pump (Relay)Fuses Usage
02A Oxygen Sensors
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control System
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
O2B Oxygen Sensors
AIRBAGSupplemental In atable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running
Lamps (Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
DRL Daytime Running Lamps
RVC Regulated Voltage Control
5-110
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