Trailer Brake Control System: Other Chevrolet Silverado 3500 HD

Reference Information

Schematic Reference

Trailer Brake Control Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Trailer Brake Controls Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-317172-S12100958872009060900000)
2. «Connector Repairs»(ref-317172-S41839496312009060900000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-317172-S08096213032009060900000)
4. «Wiring Repairs»(ref-317172-S40815672902009060900000)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, press the brake pedal. The brake lights should illuminate and the TBCM Brake Switch Status parameter should indicate ON.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Trailer Brake Control Relay Replacement (1500)»(ref-317193-S36647972412009060900000) or «Trailer Brake Control Relay Replacement (2500, 3500)»(ref-317193-S35915619162009060900000)
2. «Control Module References»(ref-317173-S10180079792009060900000) for TBCM replacement, setup, and programming

Schematic Reference

Trailer Brake Control Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Trailer Brake Controls Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-317172-S12100958872009060900000)
2. «Connector Repairs»(ref-317172-S41839496312009060900000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-317172-S08096213032009060900000)
4. «Wiring Repairs»(ref-317172-S40815672902009060900000)

Scan Tool Reference

Control Module References for scan tool information

1. Verify that DTC U0100, U0121, U0140, or U2099 are not set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-317170-S26882385112009060900000) .
2. Verify that DTC C0035, C0040, C0045, C0050, OR C0131 are not set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-317170-S26882385112009060900000) .
3. Replace the TBCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TBCM replacement, setup, and programming

C056D 33, C056D 34, C056D 35, C056D 36 or C056D 39

The TBCM detected a failure in its microprocessor.

C056E 41

The TBCM is not programmed.

Schematic Reference

Trailer Brake Control Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Trailer Brake Controls Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-317172-S12100958872009060900000)
2. «Connector Repairs»(ref-317172-S41839496312009060900000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-317172-S08096213032009060900000)
4. «Wiring Repairs»(ref-317172-S40815672902009060900000)

Scan Tool Reference

Control Module References for scan tool information

1. Verify that DTC C056E is not set. If the DTC is set, program the TBCM.
2. Verify that DTC C056D is not set. If the DTC is set, replace the TBCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TBCM replacement, setup, and programming

Engine running, observe the scan tool TBCM Battery Voltage Signal parameter. The reading should be between 12.6 and 15.0 volts.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TBCM replacement, setup, and programming

Schematic Reference

Trailer Brake Control Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Trailer Brake Controls Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-317172-S12100958872009060900000)
2. «Connector Repairs»(ref-317172-S41839496312009060900000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-317172-S08096213032009060900000)
4. «Wiring Repairs»(ref-317172-S40815672902009060900000)

Scan Tool Reference

Control Module References for scan tool information

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TBCM replacement, setup, and programming

Ignition ON, observe the scan tool trailer brake controls user gain parameter. The reading should be between 0-100 percent, and change with operating the gain switch up or gain switch down.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Trailer Brake Control Relay Replacement (1500)»(ref-317193-S36647972412009060900000) or «Trailer Brake Control Relay Replacement (2500, 3500)»(ref-317193-S35915619162009060900000)
2. «Trailer Brake Control Module Replacement (1500)»(ref-317193-S24432398432009060900000) or «Trailer Brake Control Module Replacement (2500, 3500)»(ref-317193-S02951843562009060900000)
3. «Control Module References»(ref-317173-S10180079792009060900000) for TBCM replacement, setup, and programming

Ignition ON, observe the scan tool trailer brake controls user gain parameter. The reading should be between 0-100 percent, and change with operating the gain switch up or gain switch down.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Trailer Brake Control Switch Replacement»(ref-317193-S23770958962009060900000)
2. «Control Module References»(ref-317173-S10180079792009060900000) for TBCM replacement, setup, and programming

Symptoms - Trailer Brake Controls

Intermittent

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

Built Prior to 2010

This vehicle may be equipped with a Trailer Brake Control Module system for electric trailer brakes. The power output to the trailer brakes is based on the amount of brake pressure being applied in the vehicle's brake system. The available power output to the trailer brakes can be adjusted to a wide range of trailering situations.

Note. Connecting a trailer that is not compatible with the trailer brake system may result in reduced or complete loss of trailer braking. There may be an increase in stopping distance or trailer instability which could result in personal injury or damage to your vehicle, trailer, or other property. An aftermarket controller may be available for use with trailers with surge, air or electric-over-hydraulic trailer brake systems. To determine the type of brakes on your trailer and the availability of controllers, check with your trailer manufacturer or dealer. Do not power-up an aftermarket controller with the factory brake controller at the same time.

The vehicle is equipped with the following trailer braking components

1. Manual Trailer Brake Apply
2. Trailer Gain Adjustment
3. Trailer Brake Control Panel
4. Trailer Brake Driver Information Center Display

Built 2010 and After

Some trucks less than 3900 Kg (8600 lb) GVW with a gasoline engine may be equipped with a Trailer Brake Control Module (TBCM) or a combination Fuel Pump/Trailer Brake Control Module (FTCM) system for electric trailer brakes. Some trucks greater than or equal to 3900 Kg (8600 lb) GVW may be equipped with a integrated Trailer Brake Control Module (TBCM) system for electric trailer brakes. The power output to the trailer brakes is based on the amount of brake pressure being applied in the vehicle's brake system. The available power output to the trailer brakes can be adjusted to a wide range of trailering situations.

Note. Connecting a trailer that is not compatible with the trailer brake system may result in reduced or complete loss of trailer braking. There may be an increase in stopping distance or trailer instability which could result in personal injury or damage to your vehicle, trailer, or other property. An aftermarket controller may be available for use with trailers with surge, air or electric-over-hydraulic trailer brake systems. To determine the type of brakes on your trailer and the availability of controllers, check with your trailer manufacturer or dealer. Do not power-up an aftermarket controller with the factory brake controller at the same time.

The vehicle is equipped with the following trailer braking components

1. Manual Trailer Brake Apply
2. Trailer Gain Adjustment
3. Trailer Brake Control Panel
4. Trailer Brake Driver Information Center Display

Manual Trailer Brake Apply

The Manual Trailer Brake Apply Lever is located on the Trailer Brake Control Panel, and is used to apply the trailer's electric brakes independent of your vehicle's brakes. This lever is used in the Trailer Gain Adjustment Procedure to properly adjust the power output to the trailer brakes. Sliding the lever to the left will apply only the trailer brakes. The power output to the trailer is indicated in the Trailer Brake Display Page in the Driver Information Center. If your vehicle's service brakes are applied while using the Manual Trailer Brake Apply Lever, the trailer output power will be the greater of the two.

The trailer and the vehicle's brake lamps will come on when either vehicle braking or manual trailer brakes are applied.

Trailer Brake Control Panel

The trailer brake system has a control panel with the trailer gain and manual apply switches, and is located on the instrument panel to the left of the steering column. See appropriate Instrument Panel article for an Overview for more information on location. The control panel and switches allows you to adjust the amount of output, referred to as trailer gain, available to the electric trailer brakes and allows you to manually apply the trailer brakes. The Trailer Brake Control Panel, and switches is used along with the Trailer Brake Display Page on the Driver Information Center to adjust and display power output to the trailer brakes.

Driver Information Indicators and Messages

The following indicators are used to inform the driver of several different factors.

TRAILER CONNECTED

This message will be briefly displayed when a trailer with electric brakes is first connected to the vehicle. This message will automatically turn off in about ten seconds. The driver can also acknowledge this message before it automatically turns off.

SERVICE TRAILER BRAKE SYSTEM

This message will be displayed when there is a problem with the trailer brake control system. If this message persists over multiple ignition cycles there is a concern with the trailer brake system. Take your vehicle to an authorized GM dealer to have the trailer brake system diagnosed and repaired.

TRAILER GAIN and OUTPUT Display

This display menu can be accessed by scrolling through the Driver Information Center menu, or any time the trailer gain +/- button is depressed, or the manual trailer brake apply lever is actuated. The trailer gain display is 0 to 10 in 0.5 step increments, and indicates the current user setting of the trailer output gain. The trailer output is 0 to 10 bars in 1 bar increments, and indicates the output power provided to the trailer brakes, relative to the gain setting.