Page 1314 of 1500

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS
TRACTION CONTROL SYSTEM (TCL)13C-35
STEP 2. Using diagnostic tool MB991958, check TCL
actuator test item09: Engine TCL Drive.
To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958.
(1) Connect diagnostic tool MB991958 to the data link
connector. (Refer to P.13C-3).
(2) Turn the ignition switch to the "ON" position.
The engine speed increases after the actuator test
because the actuator test continues for only three sec-
onds. Therefore, release the accelerator pedal immedi-
ately.
(3) Use diagnostic tool MB991958 to check the actuator test.
(Refer to P.13C-3).
Item 09: Engine TCL Drive.
When the accelerator pedal is depressed at the
same time that the button for actuator test item 09
displayed on diagnostic tool MB991958 is pressed,
the system prevents the engine speed from rising for
three seconds.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect diagnostic tool MB991958.
Q: Are the check results for actuator test item 09
satisfactory?
YES : Go to Step 3.
NO : Replace the hydraulic unit (integrated with
ABS/TCL-ECU). (Refer to GROUP 35B
Hydraulic
Unit P.35B-93). Then go to Step 4.
STEP 3. Retest the system
Q: Does the TCL work normally?
YES : It can be assumed that this malfunction is intermittent.
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunction P.00-14).
NO : Replace the hydraulic unit (integrated with
ABS/TCL-ECU). (Refer to GROUP 35B
Hydraulic
Unit P.35B-93). Then go to Step 4.
STEP 4. Retest the system
Q: Does the TCL work normally?
YES : The procedure is complete.
NO : Return to Step 1.
Page 1315 of 1500

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS
TRACTION CONTROL SYSTEM (TCL)13C-36
DATA LIST REFERENCE TABLEM1136003500071
NOTE: If the ABS-8 ECU or the active wheel
speed sensor are disconnected, or if the wiring is
an open/ short circuit, the ABS 8 ECU will shut
off power supply to the respective wheel speed
sensor. All other wheel speed sensors will oper-
ate normally. To restore the power supply, the
ignition switch must be turned to the "OFF" posi-
tion then to the "ON" position again.The following items can be read by the diagnostic
tool from the ABS/TCL-ECU input data. (Refer to
P.13C-3).
NOTE: Since the TCL is controlled with the same ABS/TCL-ECU used to control the ABS, the stoplight switch
check item (No.6) used only for the ABS also appear.MUT-III
DIAGNOSTI
C TOOL
DISPLAYITEM
NO.CHECK ITEM CHECKING REQUIREMENTS NORMAL
VA L U E
FL wheel
speed sensor01 Front left wheel speed sensor Drive the vehicle Vehicle speeds
displayed on the
speedometer
and diagnostic
tool are identical. FR wheel
speed sensor02 Front right wheel speed sensor
RL wheel
speed sensor03 Rear left wheel speed sensor
RR wheel
speed sensor04 Rear right left wheel speed
sensor
Power supply
voltage05 ABS/TCL-ECU power supply
voltageIgnition switch power supply
voltageBattery positive
voltage
Stoplamp
switch
(input)*06 Stoplamp switch Depress the brake pedal. ON
Release the brake pedal. OFF
Stoplamp
switch*13 Stoplamp switch Depress the brake pedal. ON
Release the brake pedal. OFF
Pump motor 21 Pump motor When the ABS outputs the
operation permission signal
during drivingON
When the ABS outputs the
operation permission signal
during drivingOFF
Valve relay 30 Valve relayWhen the ABS outputs the
operation permission signal
during drivingON
When the ABS outputs the
operation permission signal
during drivingOFF
TCL mode 35 TCL operation When the TCL outputs the
operation permission signal
during drivingON
When the TCL outputs the
operation inhibition signal
during drivingOFF
Page 1316 of 1500

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS
TRACTION CONTROL SYSTEM (TCL)13C-37
ACTUATOR TEST REFERENCE TABLEM1136003600067
NOTE: If the ABS-8 ECU or the active wheel
speed sensor are disconnected, or if the wiring is
an open/ short circuit, the ABS 8 ECU will shut
off power supply to the respective wheel speed
sensor. All other wheel speed sensors will oper-
ate normally. To restore the power supply, the
ignition switch must be turned to the "OFF" posi-
tion then to the "ON" position again.The diagnostic tool activates the following actuators
for testing. (Refer to P.13C-3).
NOTE: Since the TCL is controlled with the same ABS/TCL-ECU used to control the ABS, the FL, FR, RL or
RR Wheel ABS Drive testing items (No.01 to 04) used only for the ABS also appear. MUT-III
DIAGNOSTIC TOOL
DISPLAYITEM NO. CHECK ITEM PARTS TO BE ACTIVATED
FL wheel ABS Drive* 01 Solenoid valve for front left wheel Solenoid valves and pump
motors in the hydraulic unit
(simple inspection mode) FR wheel ABS Drive* 02 Solenoid valve for front right wheel
RL wheel ABS Drive* 03 Solenoid valve for rear left wheel
RR wheel ABS
Drive*04 Solenoid valve for rear right wheel
Engine TCL Drive 09 TCL operation check Outputs the engine torque
control signal (engine torque =
0) to PCM for three seconds.
Page 1317 of 1500

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS
TRACTION CONTROL SYSTEM (TCL)13C-38
CHECK AT ABS/TCL-ECU CONNECTOR: A-02
RESISTANCE AND TERMINAL VOLTAGE
M1136003800072
RESISTANCE AND TERMINAL VOLTAGE CHECK
CHART
.
Required Special Tools:
MB991219: Inspection Test Harness
MB991223: Harness Set
1. Disconnect the ABS/TCL-ECU connector A-02.
2. Measure the resistance and terminal voltage at the
ABS/TCL-ECU wiring harness-side connector A-02 using
the Inspection test harness MB991219 (by inserting probe)
between terminals shown in the table below and body
ground.
NOTE: The special tool (Inspection test harness) MB991219
for connector pin contact pressure should be used. The test
probe should never be forcibly inserted, as it may cause a
defective contact.
3. The terminal layouts are shown in the illustrations below.
CONNECTOR
TERMINAL NOSIGNAL CHECKING REQUIREMENT NORMAL
CONDITION
21 TCL switch Ignition
switch: "ON" When the TCL switch is not
pressed.More than 2 ohms
(open circuit)
When the TCL switch is
pressed.Less than 2 ohms
18 ABS/TCL-ECU power
supplyIgnition switch: "ON" Battery positive
voltage
Ignition switch: "START" 1 V or less
Page 1318 of 1500
TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS
TRACTION CONTROL SYSTEM (TCL)13C-39
RESISTANCE AND CONTINUITY BETWEEN
ABS-ECU AND WHEEL SPEED SENSOR
HARNESS-SIDE CONNECTOR TERMINALS
.
Required Special Tools:
MB991219: Inspection Test Harness
MB991223: Harness Set
1. Disconnect the ABS/TCL-ECU connector A-02 and the
related wheel speed sensor connector, then turn the ignition
switch to the "LOCK" (OFF) position.
2. Measure the resistance and continuity between the
ABS/TCL-ECU wiring harness-side connector A-02 and the
Wheel Speed Sensor connectors using the Inspection test
harness MB991219 (by inserting probe) and an ohmmeter
between terminals shown in the table below.
NOTE: The special tool (Inspection test harness) MB991219
for connector pin contact pressure should be used. The test
probe should never be forcibly inserted, as it may cause a
defective contact.
3. The terminal layout is shown in the table below.
Page 1320 of 1500

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS
TRACTION CONTROL SYSTEM (TCL)13C-41
VOLTAGE AND SIGNAL CHECK AT ABS-ECU
(A-02) USING OSCILLOSCOPE
NOTE: If the ABS-8 ECU or the active wheel speed
sensor are disconnected, or if the wiring is an open/
short circuit, the ABS 8 ECU will shut off power sup-
ply to the respective wheel speed sensor. All other
wheel speed sensors will operate normally. To
restore the power supply, the ignition switch must be
turned to the "OFF" position then to the "ON" position
again..
WHEEL SPEED SENSOR AIR GAP:
Sensor air gap: (0.2mm - 0.85mm).
.
Measure supply voltage for wheel speed sensor using an
oscilloscope.
(1) ABS-ECU must remain connected.
(2) Wheel speed sensors must emain connected
(3) Remove ABS connector protection cap to access terminal
location from the rear of connector for back-probing.
(4) Using probe (MB991222) , backprobe the wheel speed
sensor voltage supply circuit terminals (16, 9, 6 and 8) at
the ABS-ECU connector (A-02) individually.
(5) Connect oscilloscope (as per figure 1) shows, to the
appropriate terminal positions and check supply voltage
individually with scope.
Page 1321 of 1500
TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS
TRACTION CONTROL SYSTEM (TCL)13C-42
Connect oscilloscope to FL sensor signal terminal (16)
at ABS-ECU (A-02)
Connect oscilloscope to FR sensor signal terminal (9) at
ABS-ECU (A-02)
Connect oscilloscope to RL sensor signal terminal (6) at
ABS-ECU (A-02)
Connect oscilloscope to RR sensor signal terminal (8) at
ABS-ECU (A-02)
(6) Turn the ignition switch to the "ON" position.
Page 1323 of 1500
TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS
TRACTION CONTROL SYSTEM (TCL)13C-44
Connect oscilloscope to FL sensor signal terminal (5) at
ABS-ECU (A-02)
Connect oscilloscope to FR sensor signal terminal (10)
at ABS-ECU (A-02)
Connect oscilloscope to RL sensor signal terminal (17)
at ABS-ECU (A-02)
Connect oscilloscope to RR sensor signal terminal (19)
at ABS-ECU (A-02)
(7) Recommended Oscilloscope setting:
Y-axis: 2Volts
X-axis: 100ms
(8) Turn the ignition switch to the "ON" position.
(9) Turn wheel by hand at approximately 1 revolution per
second (r/sec) or drive on brake dynamometer at 5km/h.
The measurement reading of the active wheel speed sen-
sors on the oscilloscope should correspond to figure 3
below.
NOTE: If the oscilloscope signal shape is correct and wheel
sensor air gap is within specification, but the voltage values are
either higher or lower as shown in the table below, the wheel
speed sensor must be changed.