Traction Control System Poor Performance. GMC Truck Yukon XL

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2006 🢒 Yukon XL - 4WD 🢒 Brakes 🢒 Antilock Brake System 🢒 Traction Control System Poor Performance

Circuit Description

Important: Information contained in this diagnostic procedure is intended for use when servicing vehicles equipped with RPO JL4. Do not use this information to address concerns on vehicles equipped with NW7.

Proper operation of the traction control system (TCS) is highly dependent on the ability to apply brake pressure to a selected wheel, through the brake pressure modulator valve (BPMV), as commanded by the electronic brake control module (EBCM). The EBCM may not be able to detect certain mechanical failures that may cause the TCS to perform poorly. This diagnostic procedure is designed to help diagnose concerns of excessive wheel slip or dragging brakes during acceleration, which may occur without the presence of any DTCs.

Step	Action	Yes	No
1	Did you review the system Description and Operation and perform the necessary inspections?	Go to Step 2	Go to Symptoms - Antilock Brake System
2	Raise the vehicle so that all four wheels are about 15 cm (6 in) off of the floor. Refer to Lifting and Jacking the Vehicle . With help from an assistant, verify that the brake at each driven wheel is applying and releasing properly when the brake pedal is applied and released. Did you find and correct a concern?	Go to Step 8	Go to Step 3
3	Diagnose any hydraulic brake symptoms exhibited by the vehicle. Refer to Symptoms - Hydraulic Brakes . Did you find and correct a concern?	Go to Step 8	Go to Step 4
4	Install a scan tool. Perform dump and isolation valve testing on all of the dump and isolation valves. Refer to Brake Pressure Modulator Valve Hydraulic Testing . Did any of the pressure dump or wheel isolation tests fail?	Go to Step 6	Go to Step 5
5	Important: For 2 wheel drive vehicles, it is not necessary to perform a front wheel apply if the only concern is TC poor performance. Perform brake pressure application testing. Refer to Brake Pressure Modulator Valve Hydraulic Testing . Did either of the TC isolation valve tests fail?	Go to Step 6	System OK
6	Replace the brake pressure modulator valve (BPMV). Refer to Brake Pressure Modulator Valve Replacement . Did you complete the replacement?	Go to Step 7	--
7	Use the scan tool to perform all of the available BPMV hydraulic tests. Refer to Brake Pressure Modulator Valve Hydraulic Testing . Do the hydraulic tests show the system to be functioning normally?	Go to Step 8	Go to Step 2
8	Test drive the vehicle to verify that the concern has been corrected. Does the TCS operate normally?	System OK	Go to Step 2