Hummer H3. Manual — part 35

Battery Voltage - EBCM

Circuit/System Description

The electronic brake control module (EBCM) monitors the ignition voltage level available on the
VSES/ABS ignition 1 circuit for system operation. A low voltage condition prevents the system
from operating properly.

Conditions for Running the DTC

Vehicle speed is greater than 3 km/h (2 mph).

Conditions for Setting the DTC

The ignition voltage to EBCM is less than 6.5 volts for 7 seconds.

Action Taken When the DTC Sets

The antilock brake system (ABS), traction control system (TCS) and vehicle stability
enhancement system (VSES) are disabled for the duration of the ignition cycle.

The ABS and BRAKE indicators illuminates on the IPC.

The DIC displays the BRAKES and ABS FAULT messages.

Conditions for Clearing the DTC

The condition for the DTC is no longer present.

The EBCM automatically clears the history DTC when a current DTC is not detected in 100
consecutive drive cycles.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Circuit

Short to

Ground

Open

Short to

Voltage

Operating Conditions: Ignition ON
Parameter Normal Value: 12.6 Volts
VSES/ABS Ignition 1

0.0 Volts*

0.0 Volts*

12.6 Volts

*The scan tool will not communicate with the EBCM if there is 0 Volts on the circuit.

2008 Hummer H3

2008 ENGINE Engine Electrical - H3

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Engine running, accessories OFF, measure and record the battery voltage at the battery

terminals. The voltage should be between 12.6 and 15.0 volts.

If not within the specified range, refer to Charging System Test.

2. Observe the scan tool EBCM Battery Voltage parameter. The reading should be between

12.6 and 15.0 volts.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connectors at the EBCM.

2. With the ignition OFF and the scan tool disconnected, open and close the drivers door, and

wait 30 seconds. Test for less than 1.5 ohms between the ground circuit terminals listed
below and ground:

Terminal 4 X1

Terminal 1 X2

Terminal 32 X2

If greater than the specified range, test the ground circuit for an open/high resistance.

3. Verify that a test lamp illuminates between the B+ circuit terminals listed below and

ground:

Terminal 2 X1

2008 Hummer H3

2008 ENGINE Engine Electrical - H3

Terminal 2 X2

Terminal 31 X2

4. Verify that a test lamp illuminates between the ignition circuit terminals listed below and

ground:

Terminal 1 X1

Terminal 46 X2

If the test lamp does not illuminate, test the ignition circuit for a short to ground or an
open/high resistance.

5. If all circuits test normal, replace the EBCM.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming

DTC P0562

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0562

System Voltage Low - ECM

Diagnostic Fault Information

Circuit/System Description

The engine control module (ECM) monitors the system voltage to ensure that the voltage stays

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Performance

Ignition 1

P0562

P0562

-

-

Ground

-

P0562

-

-

2008 Hummer H3

2008 ENGINE Engine Electrical - H3

within the proper range. Damage to components, and incorrect data may occur when the voltage
is out of range.

Conditions for Running the DTC

The vehicle speed is above 8 km/h (5 mph).

The system voltage is between 9.5-18 volts.

Conditions for Setting the DTC

The ECM detects a system voltage less than 10 volts for 5 seconds.

Action Taken When the DTC Sets

DTC P0562 is a C type DTC.

Conditions for Clearing the DTC

DTC P0562 is a C type DTC.

Diagnostic Aids

A low voltage DTC in multiple modules indicates a concern with the charging system.

Reference Information

Schematic Reference

Starting and Charging Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Charging System Description and Operation

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

2008 Hummer H3

2008 ENGINE Engine Electrical - H3