Anti-Lock Brake System for Hatchback (from 07/2011)
BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ANTI-LOCK BRAKE SYSTEM (for Hatchback): C1271, C1272, C1401, C1402: Low Output Signal of Front Speed Sensor RH (Test Mode DTC)
C1402 - Front Speed Sensor LH Malfunction
DESCRIPTION
The speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU (brake actuator assembly). These signals are used for ABS control.
Speed sensor rotors have rows of alternating N and S magnetic poles, and their magnetic fields change when the rotors turn.
Each speed sensor detects that magnetic change and sends a pulse signal to the skid control ECU (brake actuator assembly).
HINT
When the connectors between the speed sensor and skid control ECU are connected, the following waveform is output.
Text in Illustration
Test Mode Diagnosis Code
HINT
* DTC C1401 and C1271 are for the front speed sensor RH.
* DTC C1402 and C1272 are for the front speed sensor LH.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. CHECK FRONT SPEED SENSOR INSTALLATION
(a) Turn the ignition switch off.
(b) Check the speed sensor installation.
OK:
There is no clearance between the sensor and the front steering knuckle.
The installation bolt is tightened properly.
Torque
8.5 N*m (87 kgf*cm, 75 in.*lbf)
Text in Illustration
NG -- INSTALL FRONT SPEED SENSOR CORRECTLY Installation (from 07/2011)
OK -- Continue to next step.
2. INSPECT FRONT SPEED SENSOR TIP
(a) Remove the front speed sensor Removal (from 07/2011).
(b) Check the speed sensor tip.
OK:
No scratches, oil, or foreign matter on the sensor tip.
NOTICE:
* If there is iron powder sticking to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign material before replacing the sensor.
* Check the speed sensor signal after cleaning or replacement Test Mode Procedure (from 07/2011).
(c) Reinstall the front speed sensor Installation (from 07/2011)
NG -- CLEAN OR REPLACE FRONT SPEED SENSOR
OK -- Continue to next step.
3. INSPECT FRONT SPEED SENSOR ROTOR
(a) Remove the front axle hub sub-assembly Removal (from 07/2011).
(b) Check the speed sensor rotor.
OK:
No scratches, oil, or foreign matter on the rotors.
NOTICE:
Check the speed sensor signal after cleaning or replacement Test Mode Procedure (from 07/2011).
HINT
If the front axle hub assembly needs to be replaced, replace it together with the front drive outboard joint shaft assembly.
(c) Reinstall the front axle hub assembly Installation (from 07/2011).
NG -- CLEAN OR REPLACE FRONT SPEED SENSOR ROTOR
OK -- Continue to next step.
4. READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)
(a) Connect the Techstream to the DLC3.
(b) Start the engine.
(c) Turn the Techstream on.
(d) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.
ABS/VSC/TRAC (Skid Control ECU)
(e) Check that there is no difference between the speed value output from the speed sensor displayed on the Techstream and the speed value displayed on the speedometer when driving the vehicle.
HINT
Factors that affect the indicated vehicle speed include tire size, tire inflation, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart On-Vehicle Inspection (from 07/2011).
OK:
The speed value output from the speed sensor displayed on the Techstream is the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).
HINT
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table (from 07/2011).
Result
B -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Anti-Lock Brake System for Hatchback (from 07/2011)
A -- Continue to next step.
5. REPLACE FRONT SPEED SENSOR
(a) Turn the ignition switch off.
(b) Replace the front speed sensor Removal (from 07/2011).
NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure (from 07/2011).
NEXT -- Continue to next step.
6. RECONFIRM DTC
(a) Clear the DTCs Anti-Lock Brake System (for Hatchback).
(b) Start the engine.
(c) Drive the vehicle at a speed of 40 km/h (25 mph) or more for at least 60 seconds.
(d) Check if the same DTC is recorded Anti-Lock Brake System (for Hatchback).
Result
NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure (from 07/2011).
HINT
* If the front axle hub assembly needs to be replaced, replace it together with the front drive outboard joint shaft assembly.
* If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table (from 07/2011).
B -- REPLACE FRONT SPEED SENSOR ROTOR Removal (from 07/2011)
A -- END