Hummer H2. Manual — part 2422

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Inspect for ABS DTCs. A faulty ABS condition may contribute to setting DTC P0719.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

3: This step isolates the brake switch as a source for setting the DTC.

DTC P0719

Step

Action

Value

(s)

Yes

No

1

Did you perform the Diagnostic System Check -
Engine Controls?

-

Go to Step 2

Go to Diagnostic

System Check -

Engine Controls

in Engine Controls

- 6.0L (LQ4)

2

1. Install a scan tool.

2. Turn ON the ignition, with the engine OFF.

3. Record the DTC Failure Records.

4. Clear the DTC.

5. Select TCC Brake Switch on the scan tool.

6. Disconnect the brake switch connector from

the brake switch.

7. Connect a test lamp from terminal C of the

brake switch connector to ground.

Does the test lamp illuminate?

IMPORTANT:

Before clearing the DTC, use the scan tool
in order to record the Failure Records.
Using the Clear Info function erases the
Failure Records from the PCM.

CAUTION:

Refer to SIR Caution in Cautions and
Notices.

-

Go to Step 3

Go to Step 4

3

Connect a fused jumper wire between terminal C
and terminal D of the brake switch connector.
Did the TCC Brake Switch status on the scan tool
change from Open to Closed?

-

Go to Step 7

Go to Step 9

Inspect the brake fuse for an open.

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

4

Refer to Circuit Protection - Fuses in Wiring
Systems.
Is the fuse open?

-

Go to Step 5

Go to Step 8

5

Test the ignition 3 voltage circuit of the brake
switch for a short to ground.
Refer to Testing for Short to Ground and extxref
document="029_body-21" filetype="sgml"
extrefid="i162420">Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 11

Go to Step 6

6

Test the signal circuit of the brake switch for a short
to ground.Refer to Testing for Short to Ground
and extxref document="029_body-21"
filetype="sgml" extrefid="i162420">Wiring Repairs
in Wiring Systems.Did you find and correct the
condition?

IMPORTANT:

The condition that affects this circuit may exist in
other connecting branches of the circuit. Refer to
Power Distribution Schematics in Wiring Systems
for complete circuit distribution.

-

Go to Step 11

Go to Step 10

7

Replace the brake switch.
Refer to Stop Lamp Switch Replacement in
Lighting Systems.
Did you complete the replacement?

-

Go to Step 11

-

8

Test the ignition 3 voltage circuit of the brake
switch for an open.
Refer to Testing for Continuity and extxref
document="029_body-21" filetype="sgml"
extrefid="i162420">Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 11

-

9

Test the signal circuit of the brake switch for an
open.Refer to Testing for Continuity and extxref
document="029_body-21" filetype="sgml"
extrefid="i162420">Wiring Repairs in Wiring
Systems.Did you find and correct the condition?

IMPORTANT:

The condition that affects this circuit may exist in
other connecting branches of the circuit. Refer to
Power Distribution Schematics in Wiring Systems
for complete circuit distribution.

-

Go to Step 11

Go to Step 10

10

Replace the PCM.
Refer to Powertrain Control Module (PCM)

-

-

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

DTC P0724

Replacement in Engine Controls - 6.0L (LQ4).
Did you complete the replacement?

Go to Step 11

11

Perform the following procedure in order to verify
the repair:

1. Select DTC.

2. Select Clear Info.

3. Turn ON the ignition, with the engine OFF.

4. Apply and release the brake pedal.

5. Verify that the scan tool TCC Brake Switch

status indicates Closed, 12 volts, for 2
seconds.

6. Select Specific DTC.

7. Enter DTC P0719.

Has the test run and passed?

-

Go to Step 12

Go to Step 2

12

With the scan tool, observe the stored information,
capture info, and DTC Info.
Does the scan tool display any DTCs that you have
not diagnosed?

-

Go to Diagnostic

Trouble Code

(DTC) List in

Engine Controls -

6.0L (LQ4)

System OK

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

Fig. 9: Brake Switch Diagram
Courtesy of GENERAL MOTORS CORP.

Circuit Description

The brake switch indicates brake pedal status to the powertrain control module (PCM). The brake switch is a

2004 Hummer H2

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2