Hummer H2. Manual — part 1186

Ignition Terminal Identification Switch

Connector Part Information

z

15355066

z

2-Way F Metri-Pack 150 Series Sealed (TN)

Pin

Wire Color

Circuit No.

Function

A

-

-

Plugged

B

BN

25

Charge Indicator Control Signal

C

GY

23

Generator Field Duty Cycle Signal

D

-

-

Plugged

Connector Part Information

z

10400853490

z

7-Way F Kostal N Series (BK)

Pin

Wire Color

Circuit No.

Function

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

DIAGNOSTIC INFORMATION AND PROCEDURES

DIAGNOSTIC STARTING POINT - ENGINE ELECTRICAL

Begin the system diagnosis with the Diagnostic System Check - Engine Electrical . The Diagnostic System
Check will provide the following information:

z

The identification of the control module(s) which command the system.

z

The ability of the control module(s) to communicate through the serial data circuit.

z

The identification of any stored diagnostic trouble codes (DTCs) and their status.

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

DIAGNOSTIC SYSTEM CHECK - ENGINE ELECTRICAL

Diagnostic System Check - Engine Electrical

A

BN

4

Accessory Voltage

B

RD/WH

342

Battery Positive Voltage

C

PK

3

Ignition 1 Voltage

D

YE

5

Crank Voltage

E

WH

1390

Acc/Run/Crank Voltage

F

RD

142

Battery Positive Voltage

G

OG

300

Ignition 3 Voltage

Step

Action

Yes

No

1

Did you perform the Battery Inspection/Test?

Go to Step 2

Go to Battery

Inspection/Test (Non-HP2)

2

Install a scan tool.
Does the scan tool power up?

Go to Step 4

Go to Scan Tool Does Not

Power Up

3

1. Access the Class 2 Power Mode in the

Diagnostic Circuit Check on the scan tool.

2. Rotate the ignition switch through all

positions while observing the ignition
switch power mode parameter.

Does the ignition switch parameter reading
match the ignition switch position for all switch
positions?

IMPORTANT:

The engine may start during the following
step. Turn OFF the engine as soon as you
have observed the Crank power mode.

Go to Step 4

Go to Power Mode

Mismatch in Body Control

System

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

SCAN TOOL DATA LIST

Powertrain Control Module (PCM)

SCAN TOOL DATA DEFINITIONS

4

1. Turn ON the ignition, with the engine

OFF.

2. Attempt to communicate with each

module on the class 2 serial data circuit.

If using a Tech 2, obtain this information
using the Class 2 Message Monitor
feature.

Does the scan tool communicate with any
module on the class 2 serial data circuit?

Go to Step 5

Go to Scan Tool Does Not

Communicate with Class 2

Device

5

1. Select the Display DTCs function for each

module.

If using a Tech 2, use the Class 2 DTC
Check feature in order to determine which
modules have DTCs set.

2. Record all of the displayed DTCs the

DTC status and the module which set the
DTC.

Does the scan tool display any DTCs?

Go to Step 6

Go to Symptoms - Engine

Electrical

6

Does the scan tool display any DTC beginning
with "U"?

Go to Diagnostic

Trouble Code

(DTC) List

Go to Step 7

7

Does the scan tool display any DTC beginning
with "P"?

Go to Powertrain

DTC list in Engine

Controls

Go to Step 8

8

Does the scan tool display any DTC beginning
with "B"?

Go to Diagnostic

Trouble Code

(DTC) List

Go to Diagnostic Trouble

Code (DTC) List

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Ignition 1 Signal

Engine 1,2 Data

Volts

9-14v

GEN L-Terminal Signal Command

Engine 2 Data

OK/No Output

OK

GEN F-Terminal Signal

Engine 2 Data

%

10-90%

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

Ignition 1 Signal

The scan tool displays the current voltage at the battery.

GEN L-Terminal Signal Command

The scan tool displays OK/No Output. The scan tool displays OK until malfunction is detected on the
generator L terminal circuit, then it reads No Output.

GEN F-Terminal Signal

The scan tool displays 0%-100%. The scan tool displays 0%-5% until the engine is running, then the
percentage value varies depending on electrical loads.

DIAGNOSTIC TROUBLE CODE (DTC) LIST

Diagnostic Trouble Code (DTC) List

DTC B1327

Circuit Description

All vehicle modules monitor system voltage. The system voltage message is sent to other modules via Class 2
message. When the system voltage drops below the specified range DTC B1327 shall set within the affected
module.

Conditions for Running the DTC

This DTC shall run only if the module has power, ground and the ignition is not in START mode. This DTC
shall execute regardless of the battery voltage, except when the DTC B1390 is set current.

Conditions for Setting the DTC

z

This DTC shall be set as current when the voltage falls below 9.0 volts for 1.2 seconds.

z

When the vehicle exits START the module shall delay checking the voltage for 2 seconds.

Action Taken When the DTC Sets

DTC

Diagnostic Procedure

Modules

B1327

DTC B1327

BCM

B1328

DTC B1328

BCM

P0562

DTC P0562

PCM

P0563

DTC P0563

PCM

P1637

DTC P1637

PCM

P0622

DTC P0622

PCM

P0615

DTC P0615

PCM

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2