Hummer H3. Manual — part 1096

Fig. 56: Endgate
Courtesy of GENERAL MOTORS CORP.

2006 Hummer H3

2006 GENERAL MOTORS H3

2007 ENGINE

Engine Cooling - H3

SPECIFICATIONS

FASTENER TIGHTENING SPECIFICATIONS

Fastener Tightening Specifications

DIAGNOSTIC INFORMATION AND PROCEDURES

DIAGNOSTIC STARTING POINT - ENGINE COOLING

Begin the system diagnosis with the diagnostic system check. Refer to Diagnostic System Check
- Vehicle . The Diagnostic System Check - Vehicle will provide the following information:

The identification of the control modules which command the system

The ability of the control modules to communicate through the serial data circuits

The identification of any stored DTCs and their status

The use of the Diagnostic System Check - Vehicle will identify the correct procedure for
diagnosing the system and where the procedure is located.

SCAN TOOL DATA LIST

Powertrain Control Module

Application

Specification

Metric

English

Coolant Heater

50 N.m

37 lb ft

Coolant Recovery Reservoir Bolt

10 N.m

89 lb in

Fan Blade Bolt

27 N.m

20 lb ft

Fan Clutch Nut

56 N.m

41 lb ft

Thermostat Housing Bolt

10 N.m

89 lb in

Water Outlet Housing Bolt

10 N.m

89 lb in

Water Pump Bolt

10 N.m

89 lb in

Water Pump Pulley Bolt

25 N.m

18 lb ft

Scan Tool Parameter

Data List

Units Displayed

Typical Data

Value

2007 Hummer H3

2007 ENGINE Engine Cooling - H3

2007 Hummer H3

2007 ENGINE Engine Cooling - H3

SCAN TOOL DATA DEFINITIONS

ECT Sensor

The scan tool displays -39°C to +140°C (-38°F to +284°F). The Engine Coolant
Temperature (ECT) sensor is mounted in the coolant stream. The powertrain control module
(PCM) applies 5 volts to the ECT sensor circuit. The sensor is a thermistor which changes
internal resistance as temperature changes. When the sensor is cold (internal resistance
high), the PCM monitors a high signal voltage and interprets it as a cold engine. As the
sensor warms (internal resistance decreases), the voltage signal decreases and the PCM
interprets the lower voltage as a warm engine.

SYMPTOMS - ENGINE COOLING

Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of the Cooling System.
Refer to Checking Aftermarket Accessories .

Inspect the easily accessible or visible system components for obvious damage or conditions
which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to
Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the
symptom:

Ignition Switch in RUN/Engine running/Automatic Transmission in PARK/Manual

Transmission in NEUTRAL/Air Conditioner is OFF

ECT Sensor

Engine Data 1,
Engine Data 2,

Engine Data 3

°C/°F

Varies

IMPORTANT: Review the system operation in order to familiarize yourself with

the system functions. Refer to Cooling System Description and
Operation.

2007 Hummer H3

2007 ENGINE Engine Cooling - H3

Engine Overheating

Loss of Coolant

Thermostat Diagnosis

Coolant Heater Inoperative

Engine Fails To Reach Normal Operating Temperature

ENGINE OVERHEATED INDICATOR ALWAYS ON

Engine Overheated Indicator Always On

Step

Action

Yes

No

DEFINITION: The Engine Hot indicator is always ON.

1

Did you perform the Diagnostic System
Check - Vehicle?

Go to Step 2

Go to
Diagnostic
System Check -
Vehicle

2

Start the engine.
Does the Check Gages indicator
illuminate?

Go to Step 3

Go to Testing
for Intermittent
Conditions and
Poor
Connections

3

1. Install a scan tool.

2. With the scan tool, observe the ECT

Sensor parameter in the powertrain
control module (PCM) data list.

Does the scan tool indicate that the ECT
Sensor parameter is within the temperature
range shown on the temperature gage?

Go to Engine
Overheating

Go to Step 4

4

Replace the instrument panel cluster (IPC).
Refer to Instrument Cluster
Replacement (Left Hand Drive) or
Instrument Cluster Replacement
(Right Hand Drive) .
Did you complete the replacement?

Go to Step 5

-

5

Operate the system in order to verify the
repair.
Did you correct the condition?

System OK

Go to Step 2

2007 Hummer H3

2007 ENGINE Engine Cooling - H3