2008 GMC ENVOY ignition

Your vehicle’s TPMS can alert you about a low tire
pressure condition but it does not replace normal tire
maintenance. SeeTire Inspection and Rotation on
page 5-72andTires on page 5-57.
Notice:Liquid tire sealants could damage the Tire
Pressure Monitor System (TPMS) sensors. Sensor
damage caused by using a tire sealant is not
covered by your warranty. Do not use liquid tire
sealants.
TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of the
TPMS sensors are missing or inoperable. When the
system detects a malfunction, the low tire warning light
ashes for about one minute and then stays on for the
remainder of the ignition cycle. A DIC warning message
is also displayed. The low tire warning light and DIC
warning message come on at each ignition cycle until the
problem is corrected. Some of the conditions that can
cause the malfunction light and DIC message to come
on are:
One of the road tires has been replaced with the
spare tire. The spare tire does not have a TPMS
sensor. The TPMS malfunction light and DIC
message should go off once you re-install the road
tire containing the TPMS sensor.
The TPMS sensor matching process was started but
not completed or not completed successfully after
rotating the vehicle’s tires. The DIC message and
TPMS malfunction light should go off once the TPMS
sensor matching process is performed successfully.
See “TPMS Sensor Matching Process” later in this
section.
One or more TPMS sensors are missing or
damaged. The DIC message and the TPMS
malfunction light should go off when the TPMS
sensors are installed and the sensor matching
process is performed successfully. See your
dealer/retailer for service.
Replacement tires or wheels do not match your
vehicle’s original equipment tires or wheels. Tires
and wheels other than those recommended for your
vehicle could prevent the TPMS from functioning
properly. SeeBuying New Tires on page 5-74.
Operating electronic devices or being near facilities
using radio wave frequencies similar to the TPMS
could cause the TPMS sensors to malfunction.
If the TPMS is not functioning it cannot detect or signal
a low tire condition. See your dealer/retailer for service if
the TPMS malfunction light and DIC message come on
and stay on.
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TPMS Sensor Matching Process
Each TPMS sensor has a unique identication code.
Any time you rotate your vehicle’s tires or replace one or
more of the TPMS sensors, the identication codes will
need to be matched to the new tire/wheel position. The
sensors are matched to the tire/wheel positions in the
following order: driver side front tire, passenger side front
tire, passenger side rear tire, and driver side rear tire
using a TPMS diagnostic tool. See your dealer/retailer for
service.
The TPMS sensors can also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. If increasing the tire’s air pressure, do not
exceed the maximum ination pressure indicated on the
tire’s sidewall.
To decrease air-pressure out of a tire you can use the
pointed end of the valve cap, a pencil-style air pressure
gage, or a key.
You have two minutes to match the rst tire/wheel
position, and ve minutes overall to match all four
tire/wheel positions. If it takes longer than two minutes, to
match the rst tire and wheel, or more than ve minutes
to match all four tire and wheel positions the matching
process stops and you need to start over.The TPMS sensor matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Turn the headlamp control from off to parking lamps
four times within three seconds. A double horn chirp
will sound and the TPMS low tire warning light will
begin to ash. The double horn chirp and ashing
TPMS warning light indicate that the TPMS matching
process has started. The TPMS warning light should
continue ashing throughout the matching
procedure.
4. Start with the driver side front tire.
5. Remove the valve cap from the valve cap stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for 10 seconds,
then stop and listen for a single horn chirp. The
single horn chirp should sound within 15 seconds,
conrming that the sensor identication code has
been matched to this tire and wheel position. If you
do not hear the conrming single horn chirp, you will
need to start over with step number one.
6. Proceed to the passenger side front tire, and repeat
the procedure in Step 5.
7. Proceed to the passenger side rear tire, and repeat
the procedure in Step 5.
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8. Proceed to the driver side rear tire, and repeat the
procedure in Step 5.
9. After hearing the conrming horn chirp for the
driver’s side rear tire, check to see if the TPMS
warning light is still ashing. If yes, turn the ignition
switch to LOCK/OFF to exit the sensor matching
process. If the TPMS warning light is not ashing,
the ve minute time limit has passed and you will
need to start the process over beginning with Step 1.
10. Set all four tires to the recommended air pressure
level as indicated on the Tire and Loading
Information label.
11. Put the valve caps back on the valve stems
Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle’s tires, including the spare tire, for signs of
wear or damage. SeeWhen It Is Time for New
Tires on page 5-73for more information.
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km). SeeScheduled Maintenance
on page 6-4.
The purpose of a regular tire rotation is to achieve
a uniform wear for all tires on the vehicle. This will
ensure that your vehicle continues to perform most
like it did when the tires were new.Any time you notice unusual wear, rotate your
tires as soon as possible and check wheel
alignment. Also check for damaged tires or wheels.
SeeWhen It Is Time for New Tires on page 5-73
andWheel Replacement on page 5-78.
When rotating your tires, always use the correct
rotation pattern shown here.
After the tires have been rotated, adjust the
front and rear ination pressures as shown on
the Tire and Loading Information label. See
Inflation - Tire Pressure on page 5-64and
Loading Your Vehicle on page 4-34.
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Fuses Usage
5 Driver Side High-Beam Headlamp
6 Driver Side Low-Beam Headlamp
7 Windshield Wiper
8 Active Transfer Case
9 Windshield Washer
10 Powertrain Control Module B
11 Fog Lamps
12 Stoplamp
13 Cigarette Lighter
15 Electric Adjustable Pedals
16 Truck Body Controller, Ignition 1
17 Crank
18 Airbag
19 Trailer Electric Brake
20 Cooling Fan
21 Horn
22 Ignition EFuses Usage
23 Electronic Throttle Control
24Instrument Panel Cluster, Driver
Information Center
25Automatic Shift Lock Control
System
26Transmission Control Module
Canister
27 Backup
28 Powertrain Control Module 1
29 Oxygen Sensor
30 Air Conditioning
31 Truck Body Controller 1
32 Trailer
33 Antilock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Blower
50 Passenger Side Trailer Turn
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Fuses Usage
5 Driver Side High-Beam Headlamp
6 Driver Side Low-Beam Headlamp
7 Windshield Wiper
8 Active Transfer Case
9 Windshield Washer
10 Powertrain Control Module B
11 Fog Lamps
12 Stoplamp
13 Cigarette Lighter
14 Ignition Coils
15Transmission Control Module
(TCM) Canister Vent
16 Truck Body Controller, Ignition 1
17 Crank
18 Airbag
19 Trailer Electric Brake
20 Cooling Fan
21 Horn
22 Ignition E
23 Electronic Throttle ControlFuses Usage
24Instrument Panel Cluster, Driver
Information Center
25Automatic Shift Lock Control
System
26 Engine 1
27 Backup
28 Powertrain Control Module 1
29 Powertrain Control Module
30 Air Conditioning
31 Injector Bank A
32 Trailer
33 Antilock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Ignition B
50 Passenger Side Trailer Turn
51 Driver Side Trailer Turn
52 Hazard Flashers
53 Transmission
54 Oxygen Sensor Bank B
55 Oxygen Sensor Bank A
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Fuses Usage
35 Transmission Control Module
36Heat Ventilation Air
Conditioning B
37 Front Parking Lamps
38 Driver Side Turn Signal
39Heat Ventilation Air
Conditioning 1
40 Truck Body Controller 4
41 Radio
42 Trailer ParkFuses Usage
43 Passenger Side Turn Signal
44 Heat Ventilation Air Conditioning
45 Rear Fog Lamps
46 Auxiliary Power 1
47 Ignition 0
48 Four-Wheel Drive
49 Blank
50 Truck Body Controller Ignition
51 Brakes
52 Truck Body Controller Run
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At Least Once a Year
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
brake. SeeParking Brake on page 2-33.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The vehicle
should start only in PARK (P) or NEUTRAL (N).
If the vehicle starts in any other position, contact
your dealer/retailer for service.
Automatic Transmission Shift Lock
Control System 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. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-33.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the ignition to ON/RUN,
but do not start the engine. Without applying the
regular brake, try to move the shift lever out
of PARK (P) with normal effort. If the shift lever
moves out of PARK (P), contact your dealer/retailer
for service.
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Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition to LOCK/OFF in each shift lever position.
The ignition should turn to LOCK/OFF only
when the shift lever is in PARK (P).
The ignition key should come out only in
LOCK/OFF.
Contact your dealer/retailer if service is required.
Parking Brake and Automatic
Transmission Park (P) Mechanism Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.
To check the parking brake’s holding ability: With
the engine running and the transmission in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.
To check the PARK (P) mechanism’s holding
ability: With the engine running, shift to PARK (P).
Then release the parking brake followed by the
regular brake.
Contact your dealer/retailer if service is required.
Underbody Flushing Service
At least every spring, use plain water to ush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
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