Page 183 of 430

Air Pressure Gage
If your vehicle has air
brakes, the air pressure
gage is located above
the switchbank in
the center of the
instrument panel.
This gage shows the air pressure for both your
front and rear brake systems.
If the needle on the gage indicates that the air
pressure is below 60 to 75 psi (415 to 517 kPa),
the low air warning light will come on. An alarm will
also sound if this happens.The top pointer shows the pressure available for the
front system, while the bottom pointer shows
pressure for the rear. There should be no more than
4 psi (28 kPa) difference showing between the
systems.
Don’t drive until both pointers are showing at least
120 psi (827 kPa), so you’ll have enough air if
you need to apply your brakes.
Hourmeter Gage
To access the engine hourmeter gage, press the
trip odometer button three times.
The instrument panel cluster displays the
accumulated engine run time hours using the
reconfigurable odometer display. The engine run
time hours displays only when the ignition is in the
LOCK or ACCESSORY position and the trip
reset button is pressed for about four seconds.
The value of the accumulated hours does
not change when the battery is disconnected.
The hourmeter resets to 0.0 when 10,000 hours
are accumulated. The instrument panel cluster
begins to reaccumulate the engine run time hours
from 0.0 hours.
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Page 393 of 430

Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough
room around the vehicle.
2. Firmly apply both the parking brake and the
regular brakes.
Do not use the accelerator pedal, and be ready
to turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to
start the engine in each gear. The starter
should work only in PARK (P), if equipped,
or NEUTRAL (N). If the starter works in
any other position, your vehicle needs service.
On manual transmission vehicles, the starter
should work only when the clutch pedal is
all the way down.
Automatic Transmission Shift
Indicator Check
Check that the indicator points to the gear chosen.
Steering Check
Be alert for any changes in steering action,
abnormal front tire wear or steering wheel position.
An inspection or service is needed when the
steering wheel is harder to turn or has too much
free play, or if there are strange sounds when
turning or parking.
Brake System Check
Be alert to illumination of the low air warning lamp
or for the tone alarm, or changes in braking
action, such as repeated pulling to one side,
unusual sounds when braking or increased
brake pedal travel. Make sure air brake system
reservoirs are drained daily with full system
air pressure, and check system for leaks.
Any of these conditions could indicate the need
for brake system inspection and/or service.
393
Page 420 of 430

Customer Assistance Information
Customer Assistance for Text Telephone
(TTY) Users.......................................... 406
Customer Assistance Offices.................... 406
Customer Satisfaction Procedure.............. 404
GM Mobility Reimbursement Program...... 407
Reporting Safety Defects to
General Motors..................................... 415
Reporting Safety Defects to the
Canadian Government.......................... 414
Reporting Safety Defects to the
United States Government.................... 414
Roadside Assistance Program.................. 408
Service Publications Ordering
Information........................................... 415
D
Daytime Running Lamps............................. 151
Daytime Running Lamps Indicator Light....... 179
Defensive Driving........................................ 206
Diesel Engine
Engine Alarm and Automatic Shutdown.... 104
Exhaust Brake......................................... 112
Exhaust Restrictor.................................... 108Diesel Engine (cont.)
Fuel......................................................... 253
High Idle System..................................... 106
Starting.................................................... 100
Differential Lock Control, Rear Axle............. 215
Differential Lock Indicator Light.................... 178
Doing Your Own Service Work.................... 249
Dome Lamps............................................... 153
Door
Locks......................................................... 91
Power Door Locks..................................... 92
Driver
Position, Safety Belt................................... 26
Driving
At Night................................................... 223
City.......................................................... 227
Defensive................................................. 206
Drunken................................................... 207
Freeway................................................... 228
Hill and Mountain Roads.......................... 230
In Rain and on Wet Roads...................... 224
Rocking Your Vehicle to Get it Out.......... 236
Tow Hooks............................................... 237
Winter...................................................... 231
Dual Tire Operation..................................... 323
420
Page 421 of 430

E
Electrical System
Add-On Equipment................................... 340
Fuses and Circuit Breakers...................... 341
Fusible Links............................................ 341
Headlamp Wiring..................................... 341
Instrument Panel Fuse Block................... 342
Power Windows and Other Power
Options................................................. 341
Underhood Fuse Block............................. 344
Windshield Wiper Fuses........................... 341
Engine
Air Cleaner/Filter...................................... 280
Alarm and Automatic Shutdown................ 104
Battery..................................................... 304
Change Engine Oil Light.......................... 176
Check and Service Engine Soon Light..... 174
Checks Before Operating......................... 109
Coolant...........................................284, 287
Coolant Heater......................................... 111
Coolant Temperature Gage...................... 173
Diesel Engine Exhaust Brake................... 112
Drive Belt Routing.................................... 355
Exhaust................................................... 131
Exhaust Restrictor.................................... 108
Fan Breakage.......................................... 250Engine (cont.)
Fan Noise................................................ 294
High Idle System..................................... 106
Oil ...................................................268, 272
Oil Life System.......................276, 278, 279
Overheating............................................. 288
Overspeed Warning Light......................... 177
Reduced Power Light............................... 179
Shutdown Warning Light.......................... 177
Speed Limiter.......................................... 164
Starter Over-Crank Protection.................... 97
Starting Your Diesel................................. 100
Starting Your Gasoline............................... 97
Entry Lighting.............................................. 154
Event Data Recorders (EDR)...................... 409
Exhaust Brake Indicator Light...................... 178
Exhaust Restrictor....................................... 108
Extender, Safety Belt..................................... 41
Exterior Lamps............................................ 150
F
Filter
Engine Air Cleaner................................... 280
Filter Minder Gage...................................... 182
Finish Damage............................................ 338
Fixed Mast Antenna.................................... 204
421