Data Display

The scan tool displays the module data. This information assists in determining whether the module is operating properly, and whether the module is sending or receiving the proper data to and from a particular system. The module uses data received from other systems in order to carry out some functions. If the module receives the incorrect data from another system, the module may function improperly. Use the scan tool in order to review the data from the systems that interact with the module.

Displayed Input/Output Status

The scan tool also displays the module input/output status. Select the module input/output status display in order to display the data and determine if the switched inputs/outputs may be properly interpreted. The display also indicates if the input/output has changed states. For example, when a door is closed, the scan tool displays the input status of the door ajar switch as INACTIVE. When the door is open, the scan tool reads ACTIVE. Use this type of information when diagnosing a malfunction associated with a particular module input or an input that is shared with another system.

Control Outputs

Use a scan tool in order to control the module output functions. When the module output control is selected, the scan tool can command the module to turn an output on or off. This feature may be used in order to determine if the module is able to control an output regardless of the inputs or any specific program instructions. Once a test is selected, the scan tool will command the module to energize the selected output. The scan tool then displays the status of the selected output. The displayed information represents only what was module commanded, not what action was actually taken. Verify that the module is performing each of the selected output functions.

Scan Tool Menus

Refer to the Scan Tool Manual for complete information on scan tool diagnostics. The following selections appear under DRP/ABS/TCS/TIM/VSES. The TCS and VSES systems are optional and will only appear if equipped.

Diagnostic Trouble Codes (DTC)

The diagnostic trouble codes (DTC) function has the following 3 modes:

DTC Information: Current or history DTCs stored by the EBCM may be displayed.

DTC History: Displays the conditions under which a history DTC was set and the number of occurrences of the DTC.

Clear DTC Information: Current or history DTCs stored by the EBCM may be cleared.

Data Display

For the Data Display parameters, refer to Scan Tool Data List and Scan Tool Data Definitions .

Snapshot

In this test mode, the scan tool captures the data listed in the data displays before and after a snapshot-triggering condition which may or may not set a DTC.

Special Functions

In this test mode, the scan tool may be used in order to perform functional tests on the system which help verify proper operation. Malfunction conditions may be further identified by testing and observing the test results. You must first clear any DTCs before any tests in Special Functions may be performed. Only the test that are equipped on the vehicle will be displayed. The Special Functions are grouped in the following manner:

The Special Functions are detailed below.

Solenoid Test-Pressure Hold

This test activates the selected wheel circuit inlet valve, placing the valve in the pressure hold position. When the valve is in the pressure hold position, the valve will not allow master cylinder pressure to be delivered to the hydraulic wheel circuit. This is done under actual operating conditions when the EBCM determines that the wheel is moving too slowly. The EBCM holds additional master cylinder pressure from the hydraulic wheel circuit in an attempt to allow the circuit to rotate at an appropriate speed. The scan tool commands the valve to close. This should allow the technician to spin the wheel even though an assistant is applying pressure to the brake pedal. Perform the following test:

1. Turn OFF the ignition.
2. Install a scan tool.
3. Turn ON the ignition, with the engine OFF.
4. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Ensure that all of the wheels are about 15 cm (6 in) off of the floor.
5. Place the gear selector in the NEUTRAL position.
6. Select the Special Functions from the DRP/ABS/TCS/TIM/VSES menu.
7. Select the Solenoid Test. Have an assistant command Inlet Valve Solenoid of the appropriate wheel using the scan tool.
8. Have the assistant press and hold the brake pedal.
9. Attempt to move the wheel being tested by hand. The wheel should move even though the assistant is applying pressure to the brake pedal. The front wheels may be difficult to turn by hand, but may be moved if the system is working properly.

Solenoid Test-Pressure Release

This test activates the selected hydraulic wheel circuit outlet valves, placing them in the pressure reduce position. When in the pressure reduce position, the valve will allow wheel caliper pressure to be returned to the master cylinder circuit. This is done under actual operating conditions because the EBCM has determined that the wheel is moving too slowly, and holding additional master cylinder pressure from it has not allowed it to rotate at an appropriate speed. The scan tool commands the valves to these positions which should allow the technician to spin the wheel even though an assistant is applying pressure to the brake pedal. Perform the following test:

1. Turn OFF the ignition.
2. Install a scan tool.
3. Turn ON the ignition, with the engine OFF.
4. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Ensure that all of the wheels are about 15 cm (6 in) off of the floor.
5. Place the gear selector in the NEUTRAL position.
6. Select the Special Functions from the DRP/ABS/TCS/TIM/VSES menu.
7. Select the Solenoid Test. Have an assistant command the Outlet Valve Solenoid of the appropriate wheel using the scan tool.
8. Have the assistant press and hold the brake pedal.
9. Attempt to move the wheel being tested by hand. The wheel should move even though the assistant is applying pressure to the brake pedal. The front wheels may be difficult to turn by hand, but may be moved if the system is working properly.

Automated Test

This test cycles each valve solenoid and the pump motor (as well as the necessary relays) in order to verify component operation. This test is identical to the Initialization Sequence. If a malfunction is detected, the EBCM will set DTCs. The DTCs will be displayed upon completion of the test. Perform the following test:

1. Turn OFF the ignition.
2. Install a scan tool.
3. Turn ON the ignition, with the engine OFF.
4. Select the Special Functions from the DRP/ABS/TCS/TIM/VSES menu.
5. Select the Automated Test.
6. Run the Automated Test.
7. Record any DTCs that were set.

TCS Test

This test runs the pump motor in order to apply fluid pressure to the front wheel circuits.

Perform the following test. This test does NOT require an assistant:

1. Turn OFF the ignition.
2. Install a scan tool.
3. Turn ON the ignition, with the engine OFF.
4. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Ensure that all of the wheels are about 15 cm (6 in) off of the floor.
5. Select the Special Functions from the DRP/ABS/TCS/TIM/VSES menu.
6. Select the TCS Test.
7. Command the TCS Test ON with the scan tool. The pump motor will turn on for approximately 25 seconds.
8. Attempt to move each front wheel by hand. The wheels should not move due to the pump motor running and applying pressure to the front wheels.

Normal Mode Eavesdrop

This test is used to monitor the class 2 serial data messages that relate to the DRP/ABS/TCS/TIM/VSES (if equipped). Only the parameters of the options that the vehicle is equipped will be displayed. The normal mode eavesdrop function has the following 2 modes:

Phase 1-4: The term phase refers to the ignition switch changing states. The data parameters shown will display a value only when there is a change in the ignition state. Otherwise, the scan tool displays all asterisks next to each parameter.

No Phase: The data parameters shown are not affected by the changing of ignition states. The scan tool will display a value only when there is a class 2 serial data message that relates to the individual parameter. Otherwise, the scan tool displays all asterisks next to each parameter.

Phase 1-4

The following is a list of parameters for Phase 1-4 listed in alphabetical order.

ABS Failed Lamp Command: Displays Off or On. Indicates if the EBCM is commanding the ABS indicator ON.

ABS Reference Speed: Displays 0 to 255 km/h (0 to 159 mph). The vehicle speed from the average of all four wheel speeds.

Engine RPM: Displays from 0 to 9999 rpm. The crankshaft rotation speed.

Engine Type: Displays the type of the engine in the vehicle.

Estimated Trans. Gear: Displays Park, Reverse, Neutral, First, Second, Third, or Fourth. The estimated state of the transmission gear.

Extended Travel Brake Switch: Displays Applied or Released. The state of the extended travel brake switch.

Intake Air Temperature: Displays -40°C to 151°C (-40°F to 304°F). The temperature of the intake manifold air.

Lateral Acceleration: Displays -1.2 to 1.2 g. The lateral acceleration from the lateral accelerometer signal.

Low Tire Pressure: Displays Yes or No. Indicates if the EBCM has determined that a tire has low pressure.

Powertrain TCS Failure: Displays Yes or No. Indicates if the PCM has suspended TCS due to a malfunction related to TCS.

Red Brake Warning Indicator: Displays Off or On. Indicates if the EBCM is commanding the red BRAKE warning indicator ON.

Rough Road Parameter: Displays 0 to 1 g. The EBCM calculation of the road surface, this information is sent to the PCM over the class 2 serial data line. The PCM uses this information for misfire detection.

Service Stability System: Displays Off or On. Indicates if the EBCM is commanding the SERVICE STABILITY SYSTEM message to be displayed on the DIC.

State of Health Present: Displays Yes or No. Indicates if the EBCM is sending the proper state of health messages.

Stop Lamp Switch: Displays Applied or Released. The state of the brake switch.

System Power Mode: Displays Run, Crank, Accessory, Unlock, Off Awake, RAP Unlock, or RAP. The state of the ignition as reported by the dash integration module (DIM).

TCC/Brake Switch Active: Displays Yes or No. Indicates whether the TCC/brake switch is applied

TCS Equiped: Displays Yes or No. Indicates if the vehicle is equipped with TCS.

TCS Failed Lamp Command: Displays Off or On. Indicates if the EBCM is commanding the TRACTION OFF indicator ON.

Temporary Inhibit of TCS: Displays Yes or No. Indicates if the EBCM has suspended TCS due to a malfunction or the driver using the traction control switch.

TPS - Pedal Position: Displays 0 to 100%. The throttle angle. The display should read 0% at idle and 100% at wide open throttle.

Transmission Type: Displays the type of the transmission in the vehicle.

VIN Packet #2: Displays the VIN packet #2.

VSES Active: Displays Yes or No. Indicates if the VSES is currently active.

VSES Equiped: Displays Yes or No. Indicates if the vehicle is equipped with VSES.

No Phase

The following is a list of parameters for No Phase listed in alphabetical order.

ABS Active Indicator: Displays Off or On. Indicates if the ABS active indicator is currently ON.

Low Tire Pressure Reset Switch: Displays Was Pressed. Indicates if the tire pressure reset switch was pressed.

Stability System Active: Displays Off or On. Indicates if the EBCM is commanding the STABILITY SYSTEM ACTIVE message to be displayed by the DIC.

TCS Active Message Command: Displays Off or On. Indicates if the EBCM is commanding the TRACTION CONTROL SYSTEM ACTIVE message to be displayed by the DIC.

TCS Off Lamp Command: Displays Off or On. Indicates if the EBCM is commanding the TRACTION OFF indicator ON due to the traction control switch.

TCS On/Off Switch: Displays Was Pressed. Indicates if the traction control switch was pressed.

Traction Ready Message Comm.: Displays Off or On. Indicates if the EBCM is commanding the TRACTION OFF indicator OFF due to the traction control switch.

Traction Suspended Message Comm.: Displays Off or On. Indicates if the EBCM is commanding the TRACTION OFF indicator ON due to the Brake Thermal Model fault.

Pump Motor Test

This test is used to command the pump motor ON and OFF.

Tire Pressure Reset

The tire inflation monitor (TIM) can be reset using the scan tool. Be sure that all tires are set to the proper pressures.

TCS On/Off Test

This test is used to command the TCS ON and OFF. This test performs the same function as the traction control switch.

Steering Position Sensor Test

This test monitors the dual analog steering angle position. Perform the following test only after the steering wheel position sensor (SWPS) has been centered:

1. Turn OFF the ignition.
2. Install a scan tool.
3. Start the engine.
4. Place the gear selector in the PARK position.
5. Turn the steering wheel to the left lock position.
6. Select the Special Functions from the DRP/ABS/TCS/TIM/VSES menu.
7. Select the Steering Position Sensor Test.
8. When the scan tool displays Turn Steering Wheel, turn the steering wheel once to the right lock position.
9. The scan tool will display whether or not the steering wheel position sensor passes the test.

Automated Bleed

The Automated Bleed mode of the scan tool is used during bleeding of the ABS System. Refer to Antilock Brake System Automated Bleed Procedure .