Scan Tool Diagnostics. GMC Truck Yukon

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2000 🢒 Yukon - 2WD 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Scan Tool Diagnostics

Refer to the Scan Tool Manual for complete information about Scan Tool Diagnostics.

F0 - Diagnostic Trouble Codes (DTCs)

The Diagnostic Trouble Codes (DTCs) function has 3 modes that are described below:

•	DTC Information: In this mode, current or history DTC(s) stored by the EBCM can be displayed.

•	History Data: In this mode, DTC data is stored for the last 12 DTC events. This data includes information that was recorded when the DTC(s) was set.

•	Clear DTC Information: In this mode, a current or history DTC can be cleared from the EBCM memory. History data is not cleared from the EBCM memory.

F1 - Data Display

The Data Display function utilizes two special function keys and a data list which details the ABS and traction control parameters. Use the special function keys as follows:

•	DTCs -- This function is used to instantly read a stored DTC(s).

•	Quick Snap -- This function is used to record instant events.

Refer to Scan Tool Data List to view the available parameters for this vehicle. Refer to Scan Tool Data Definitions for ABS and Traction control parameter descriptions.

In this mode, the scan tool can be used to perform functional tests on the EBCM which help verify proper operation. Malfunction conditions can be further identified by testing and observing the test results. DTCs must be cleared before tests can be performed and the ignition must be ON in order to perform a test(s). The Scan Tool Output Controls are grouped as follows:

Scan Tool Output Control

Additional Menu Selection(s)

Description

Function Test

The Function Test commands the EBCM internal relay, valve solenoids and the pump motor on and off in order to verify proper component operation. If a malfunction is detected, the EBCM will set a DTC(s).

Automated Bleed

This function cycles each valve solenoid and the pump motor in a special sequence in order to bleed air out of the BPMV after removal or installation of brake lines or BPMV replacement. Refer to Antilock Brake System Automated Bleed Procedure for more information about this function.

ABS Motor

The ABS Motor test commands the ABS pump motor on in order to verify proper component operation. If a malfunction is detected, the EBCM will set a DTC(s).

System Identification

This function is used to identify the hardware and the software revision of the EBCM.

Tire Size Calibration

This function is used to program tire size information into the EBCM memory. This must be done when a new EBCM is installed in the vehicle or when different size tires/rims are installed on the vehicle.

Important: The VCM/PCM must also be programmed with the correct tire size calibration when wheel/tire size is changed. Refer to VCM Replacement/Programming in Engine Controls-4.3L or Powertrain Control Module Replacement in Engine Controls-4.8L, 5.3L, and 6.0L.

Lamp Tests

•

ABS Lamp

•	Brake Lamp

This function allows for activation of the ABS and BRAKE indicators. The Lamp tests aid in diagnosing indicator malfunctions. These tests allow the technician to command the indicators On and Off.

Solenoid Tests

•	Left Front Isolation Valve

•	Left Front Dump Valve

•	Right Front Isolation Valve

•	Right Front Dump Valve

•	Rear Isolation Valve

•	Rear DumpValve

Pressure Hold

The Solenoid Test for isolation valves commands the selected brake circuit isolation valve on, placing it in the pressure hold position. When in the pressure hold position, the valve will not allow master cylinder pressure to be delivered to the brakes.

Pressure Reduce

The Solenoid Test for dump valves commands the selected brake circuit dump valve on, placing it in the pressure reduce position. When in the pressure reduce position, the valve allows hydraulic fluid to escape from the brake circuit, be stored in the accumulator and then later returned to the master cylinder.

Solenoid Test Procedure

Raise the vehicle so the wheels are about 6 inches off of the floor. Refer to Lifting and Jacking the Vehicle in General Information.
Place the transmission shift lever in neutral.
Select the Special Functions menu on the scan tool.
Select the desired valve Solenoid Test.
Command the solenoid On with the scan tool.
Have an assistant apply the brake.
Attempt to move the wheel being tested by hand. It should move even though the brake is applied.

ABS Relay

The ABS Relay test commands the ABS relay on and off to verify proper component operation. If a malfunction is detected, the EBCM will set a DTC(s).

Low Trac Lamp

This function allows for activation of the LOW TRACTION indicator. The Low Trac Lamp test aids in diagnosing indicator malfunctions. The test allows the technician to command the indicator On and Off.

Traction Off Lamp

This function allows for activation of the TRACTION OFF indicator. The Traction Off Lamp test aids in diagnosing indicator malfunctions. The test allows the technician to command the indicator On and Off.

Requested Torque

This function allows the technician to request engine torque reduction in order to verify proper operation of the traction control system.

F3 - Snapshot

In this mode, the scan tool records the data displays before and after a snapshot. The following snapshot triggering options are available:

•	Manual Trigger -- The technician triggers the snapshot manually.

•	Any Code -- The snapshot triggers when a specific (technician selected) DTC sets.

•	Single Code -- The snapshot triggers when any DTC sets.

•	Auto Trigger (ABS only) -- The snapshot triggers within the following conditions:

-	Wheel speed out of range -- The snapshot will trigger when a WSS input is +/- 7 mph than the other 2 WSS inputs.

-	ABS Stop -- The snapshot will trigger when an ABS event occurs.