Hummer H2. Manual — part 2478

7

connector and the AT inline 20-way
connector.

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 an open
condition?

-

Go to Step 12

Go to Step 11

8

Replace the automatic transmission wiring
harness.
Refer to Valve Body and Pressure Switch
Replacement .
Did you complete the replacement?

-

Go to Step 12

-

9

Replace the TFT sensor.
Refer to Valve Body and Pressure Switch
Replacement .
Did you complete the replacement?

-

Go to Step 12

-

10

1. Replace the automatic transmission

wiring harness.

2. Replace the TFT sensor.

Refer to Valve Body and Pressure Switch
Replacement .Did you complete the
replacements?

-

Go to Step 12

-

11

Replace the PCM.
Refer to Powertrain Control Module (PCM)
Replacement in Engine Controls - 6.0L (LQ4).
Did you complete the replacement?

-

Go to Step 12

-

12

Perform the following procedure in order to
verify the repair:

1. Select DTC.

2. Select Clear Info.

3. Operate the vehicle under the following

conditions:

z

Turn ON the ignition, with the
engine OFF.

z

The Trans. Fluid Temp. must be
greater than -40°C (-40°F) for 6
seconds.

4. Select Specific DTC.

5. Enter DTC P0713.

-

2004 Hummer H2

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

DTC P0719

Has the test run and passed?

Go to Step 13

Go to Step 2

13

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. 8: 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

normally-closed switch that supplies battery voltage on the TCC brake switch signal circuit to the PCM.
Applying the brake pedal opens the switch, interrupting voltage to the PCM. When the brake pedal is released,
the PCM receives a constant voltage signal. If the PCM receives a zero voltage signal at the brake switch input,
and the torque converter clutch (TCC) is engaged, the PCM de-energizes the TCC solenoid valve. The PCM
disregards the brake switch input for TCC scheduling if there is a brake switch circuit fault.

When the PCM detects an open brake switch circuit, 0 volts, low input, during accelerations, then DTC P0719
sets. DTC P0719 is a type C DTC.

Conditions for Running the DTC

z

No VSS assembly DTCs P0502 or P0503.

z

The ignition is ON.

z

DTC P0719 has not passed.

Conditions for Setting the DTC

The PCM detects an open brake switch or circuit, 0 volts, for 15 minutes without changing for 2 seconds, and
the following events occur eight times:

z

The vehicle speed is less than 8 km/h (5 mph);

z

then the vehicle speed is 8-32 km/h (5-20 mph) for 4 seconds;

z

then the vehicle speed is greater than 32 km/h (20 mph) for 6 seconds.

Action Taken When the DTC Sets

z

The PCM does not illuminate the malfunction indicator lamp (MIL).

z

The PCM disregards the brake switch input for TCC scheduling.

z

The PCM uses throttle position and vehicle speed to determine application and release of the TCC.

z

The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM
stores this information as Failure Records.

z

The PCM stores DTC P0719 in PCM history.

Conditions for Clearing the DTC

z

A scan tool can clear the DTC.

z

The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-
emission-related diagnostic fault occurring.

z

The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is
OFF long enough in order to power down the PCM.

Diagnostic Aids

z

Inspect the brake switch for proper mounting and operation.

2004 Hummer H2

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