Electronic Stability Program: 4F-35
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC C1028: Master Cylinder Pressure Sensor Circuit Failure
S7RS0B4604031
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC Detecting Condition Trouble Area
Mechanical switch failure, failure in switch wiring is
shorted to ground.
• ESP® OFF switch
• ESP® OFF switch circuit
• ESP® control module
Step Action Yes No
1 Was “Electronic Stability Program Check” performed? Go to Step 2. Go to “Electronic
Stability Program
System Check”.
2 Check ESP® OFF switch condition
Is ESP
®
OFF switch is OFF condition?
Go to Step 3. ESP® OFF switch
turned OFF condition
and recheck.
3 Check ESP® OFF switch
1) Turn ignition switch to OFF position.
2) Remove ESP® OFF switch referring to “ESP® OFF
Switch Removal and Installation”.
3) Check for proper connection at each terminal of ESP®
OFF switch.
4) If OK, then check ESP® OFF switch referring to “ESP®
OFF Switch Inspection”.
Is it good condition?
Go to Step 4. Replace ESP® OFF
switch.
4 Check ESP® OFF switch circuit
1) Disconnect ESP® control module connector.
2) Check for proper connection to ESP® control module
connector at “E85-7” terminal.
3) If OK, then check resistance between “E85-7” terminal
and vehicle body ground.
Is resistance infinity?
Substitute a known-
good ESP® hydraulic
unit / control module
assembly and recheck.
“LT GRN/RED” wire
circuit is shorted to
ground.
DTC Detecting Condition Trouble Area
Input signal voltage from master cylinder pressure sensor
in ESP® control module is too high or low.
• Leakage or air in the hydraulic brake system
• Clearance between brake pad and disc too high
Step Action Yes No
1 Was “Electronic Stability Program Check” performed? Go to Step 2. Go to “Electronic
Stability Program
System Check”.
2 Check brake system
1) Check brake system as follows.
• Leakage or air in the hydraulic brake system
• Clearance between brake pad and disc too high
Are they in good condition?
Go to Step 3. Repair, replace or
adjust.
3 Check sensor calibration
1) Calibrate master cylinder pressure sensor referring to
“Sensor Calibration”.
2) Clear all DTC(s) and recheck DTC.
Is DTC C1028 still detected?
Substitute a known-
good ESP® hydraulic
unit / control module
assembly recheck.
Master cylinder
pressure sensor
calibration was
incompleted.