Page 3132 of 3870
The system closes the inlet and outlet solenoids to hold the fluid pressure to the
wheel cylinders. The brake fluid, which is pumped through the hydraulic unit
reservoir, may exceed a predetermined pressure. In that case, the excessive fluid is
returned through the relief valve to the hydraulic unit reservoir.
Fig. 28: Status Of Operation Valve Specification
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
WHEN THE ACTIVE SKID CONTROL IS DECREASING THE FLUID PRESSURE WHILE THE BRAKE PEDAL
IS DEPRESSED NOTE: *: When the ASC is operating while the brake pedal is
depressed, the suction valve turns on and off according to
the brake fluid amount supplied to the buffer chamber.
2004 Mitsubishi Endeavor LS
2004 BRAKES Traction Control, Active Skid Control System - Endeavor
Page 3133 of 3870
Fig. 29: Active Skid Control Is Decreasing Diagram
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
The system closes the inlet solenoid and opens the outlet solenoid. This causes the
brake fluid in the wheel cylinders to return to the buffer chamber, and decreases the
fluid pressure in the wheel cylinders. If the returned brake fluid pressure exceeds a
predetermined pressure, excessive brake fluid is returned to the master cylinder.
2004 Mitsubishi Endeavor LS
2004 BRAKES Traction Control, Active Skid Control System - Endeavor
Page 3134 of 3870

Fig. 30: Status Of Operation Valve Specificatio
n
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
TRACTION CONTROL SYSTEM OPERATION The TCL/ASC-ECU receives information from the PCM, the G and yaw-rate
sensor, and the wheel speed sensor. If the ECU determines that a road wheel is
spinning, it will control the fluid pressure to the spinning wheel to apply torque to
the other road wheels. The operations of the ABS solenoid valves and the active
skid control system valves are the same as for the active skid control system.
Furthermore, the system also controls the engine if the accelerator pedal is
depressed excessively. TCL/ASC DIAGNOSIS INTRODUCTION TO TRACTION CONTROL/ACTIVE SKID CONTROL SYSTEM DIAGNOSIS The traction control/active skid control system (TCL/ASC) is a system that has
added the cut valve and suction valve to the conventional ABS system. These
valves are used to control each of the road wheels independently. These differences
include sounds, sensations, and vehicle performance that owners and service
technicians who are not familiar with TCL/ASC may not be used to.
Some operational characteristics may seem to be malfunctions, but they are simply
signs of normal TCL/ASC operation. When diagnosing the TCL/ASC system, keep
these operational characteristics in mind. Inform the owner of the kind of
performance characteristics to expect from an TCL/ASC-equipped vehicle. TCL/ASC Diagnostic Trouble Code Detection Conditions TCL/ASC diagnostic trouble codes (TCL/ASC DTCs) are set under different
conditions, depending on the malfunction detected. Most TCL/ASC DTCs will only
be set during vehicle operation. Some TCL/ASC DTCs will also be set during the
TCL/ASC self-check immediatel
y after the en
gine is started.
NOTE: *: When the ASC is operating while the brake pedal is
depressed, the suction valve turns on and off according to
the brake fluid amount supplied to the buffer chamber.
2004 Mitsubishi Endeavor LS
2004 BRAKES Traction Control, Active Skid Control System - Endeavor
Page 3242 of 3870

Fig. 96: Solenoid Valve And Motor Power Supply Circuit Diagram & Connector Identification
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
CIRCUIT OPERATION
The TCL/ASC-ECU contains the power supply circuit (terminal 11) for the
solenoid valve. The solenoid valve is energized by the valve relay, which i
incorporated in the TCL/ASC-ECU. The valve relay, which is incorporated in the TCL/ASC-ECU, is always
energizing the solenoid valve unless the initial check is in progress when the
ignition switch is turned on. The TCL/ASC-ECU activates the solenoid valve by turning on its driving
transistor.
TCL/ASC DTC SET CONDITIONS These diagnostic trouble codes will be set under the cases below.
The solenoid valve is not energized even after the TCL/ASC-ECU has turned
on the driving transistor (Open circuit is present in the power supply circuit to
the TCL/ASC-ECU solenoid valve, or the valve relay has failed). The solenoid valve is not energized even after the TCL/ASC-ECU has turned
on the driving transistor (Open circuit is present in the solenoid valve circuit
inside the TCL/ASC-ECU, or the valve relay has failed). After the TCL/ASC-ECU has turned off the driving transistor, the solenoid
valve still remains energized (short in the solenoid valve circuit). When a solenoid valve failure is detected
TROUBLESHOOTING HINTS (The most likely causes for these DTCs are to set are:)
Current trouble
Dama
ged wirin
g harness or connector CAUTION: If there is any problem in the CAN bus lines, an
incorrect diagnostic trouble code may be set. Prior to
this diagnosis, diagnose the CAN bus lines.
2004 Mitsubishi Endeavor LS
2004 BRAKES Traction Control, Active Skid Control System - Endeavor
Page 3243 of 3870
Malfunction of the hydraulic unit (integrated with TCL/ASC-ECU)
Past trouble
Carry out diagnosis with particular emphasis on connector(s) or wiring harness
in the power supply circuit (terminal 11) to the TCL/ASC-ECU solenoid valve
or ground circuit (terminal 12). For diagnosis procedures, refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS
).
DIAGNOSIS Required Special Tools:
MB991958: Scan Tool (MUT-III Sub Assembly)
MB991824: Vehicle Communication Interface (V.C.I.) MB991827: MUT-III USB Cable MB991910: MUT-III Main Harness A
MB991970: ABS Check Harness
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
1. Connect scan tool MB991958 to the data link connec
tor. CAUTION: To prevent damage to scan tool MB991958,
always turn the ignition switch to the
"LOCK" (OFF) position before connecting or
disconnecting scan tool MB991958.
2004 Mitsubishi Endeavor LS
2004 BRAKES Traction Control, Active Skid Control System - Endeavor
Page 3251 of 3870
Q: Is TCL/ASC-ECU connector A-32 damaged?
YES: Repair or replace the damaged component(s). Then go to Step 5.
NO: An open or short circuit may be present in the solenoid valve power
supply circuit. Repair the wiring harness between TCL/ASC-ECU
connector A-32 terminal 11 and fusible link No. 3. Then go to Step 4.
STEP 5. Measure the resistance at TCL/ASC-ECU connector A-32.
1. Disconnect the connector A-32, and connect special tool ABS Check
Harness (MB991952) to the wiring harness-side connector.
2. Measure the resistance between terminal 12 and ground. It should be 2
ohms or less. NOTE: Do not connect special tool ABS Check Harness
(MB991952) to the TCL/ASC-ECU.
2004 Mitsubishi Endeavor LS
2004 BRAKES Traction Control, Active Skid Control System - Endeavor
Page 3259 of 3870
6. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is C1226, C1231, C1236, C1241, C1246, C1251, C1256, C1261, C1300,
C1305, C1310 or C1315 set?
YES: Go to Step 1.
NO: The procedure is complete.
DTC C1266: MOTOR STUCK, DTC C1273: MOTOR DRIVE CIRCUIT STUCK OFF, DTC C1274: MOTOR DRIVE
CIRCUIT STUCK ON Fig. 105: Solenoid Valve And Motor Power Su
pp
ly Circuit Dia
gram &
2004 Mitsubishi Endeavor LS
2004 BRAKES Traction Control, Active Skid Control System - Endeavor
Page 3260 of 3870

Connector Identificatio
n
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
CIRCUIT OPERATION
The TCL/ASC-ECU contains the power supply circuit (terminal 33) for the
pump motor. The pump motor is energized by the motor relay, which is
incorporated in the TCL/ASC-ECU. The motor relay, which is incorporated in the TCL/ASC-ECU, is always off
unless the motor solenoid valve check is activated when the vehicle is started. The TCL/ASC-ECU activates the pump motor by turning on the ECU built-in
motor relay when the ABS is working.
TCL/ASC DTC SET CONDITIONS These diagnostic trouble codes will be set under the cases below. DTC C1266: MOTOR SYSTEM (SEIZURE)
If the TCL/ASC-ECU determines that the pump motor is not running smoothly
(i.e. motor seizure) after the motor relay is turned off, this DTC will be set.
DTC C1273: MOTOR RELAY PROBLEM (STUCK OFF)
If the TCL/ASC-ECU determines that the motor is not running after the motor
relay is turned on, the ECU determines that the motor relay is stuck off, and
sets this DTC.
DTC C1274: MOTOR RELAY PROBLEM (STUCK ON)
If the TCL/ASC-ECU determines that the motor is running after the motor
relay is turned off, the ECU determines that the motor relay is stuck on, and
sets this DTC.
TROUBLESHOOTING HINTS (The most likely causes for these DTCs are to set are:)
CAUTION: If there is any problem in the CAN bus lines, an
incorrect diagnostic trouble code may be set. Prior to
this diagnosis, diagnose the CAN bus lines.
2004 Mitsubishi Endeavor LS
2004 BRAKES Traction Control, Active Skid Control System - Endeavor