Kinetic Dynamic Suspension System

SUSPENSION CONTROL: KINETIC DYNAMIC SUSPENSION SYSTEM: C1776/76: Speed Sensor Circuit

DTC C1776/76 - Speed Sensor Circuit

DTC C1794/94 - Front Speed Sensor RH Circuit Malfunction

DTC C1795/95 - Front Speed Sensor LH Circuit Malfunction

DESCRIPTION

The speed sensors monitor the speed of the front wheels, and send appropriate speed signals to the stabilizer control ECU through the skid control ECU.
If trouble occurs either in the right front or left front speed sensor, the DTC (C1776/76) is output.
When inspecting in test mode, the stabilizer control ECU scans changes of the signals. If there is no change, the ECU outputs the test DTC (C1794/94, C1795/95).






WIRING DIAGRAM





INSPECTION PROCEDURE
HINT:
- Proceed to troubleshooting by following the flow chart, regardless of whether or not DTC C1776/76, C1794/94 or C1795/95 is displayed.
- Start the inspection from step 1 when using the Techstream, and start from step 2 when not using the Techstream.

PROCEDURE

1. READ VALUE USING DATA LIST
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON and the Techstream on.
(c) Select the item below in the Data List, and read its value displayed on the Techstream.

KDSS:





(d) Check that there is no difference between the value output from the speed sensor displayed on the Techstream and the value displayed on the speedometer while driving the vehicle.
OK:
There is almost no difference in the displayed speed values.
HINT: There is tolerance of ±10 % in the speedometer indication.

NG -- CHECK DTC OUTPUT (VEHICLE STABILITY CONTROL SYSTEM)
OK -- REPLACE STABILIZER CONTROL ECU
2. CHECK DTC OUTPUT (VEHICLE STABILITY CONTROL SYSTEM)
(a) Check if DTC C0200/31 or C0205/32 is output Reading and Clearing Diagnostic Trouble Codes.
Result:





HINT:
- If any other codes besides C1776/76, C1794/94 and C1795/95 are output, perform troubleshooting for those DTCs first.
- DTC C0200/31 indicates a right front speed sensor circuit malfunction for the Vehicle Stability Control System.
- DTC C0205/32 indicates a left front speed sensor circuit malfunction for the Vehicle Stability Control System.

B -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (STABILIZER CONTROL ECU - SKID CONTROL ECU)





(a) Disconnect the S36 connector from the stabilizer control ECU.
(b) Disconnect the S37 connector from the skid control ECU.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STABILIZER CONTROL ECU - SKID CONTROL ECU)
OK -- Continue to next step.
4. INSPECT SKID CONTROL ECU (FLO, FRO OUTPUT)





(a) Connect the S36 connector to the stabilizer control ECU.
(b) Connect the S37 connector to the skid control ECU.
(c) Turn the ignition switch to the ON position.
(d) Check output waveform.
(1) Using an oscilloscope, connect the terminals, as shown in the chart.










(2) Drive the vehicle at approximately 12 mph (20 km/h), and check the output waveform.
OK:
The output waveform appears as shown in the illustration.





HINT: As vehicle speed increases, the waveform cycle narrows.

NG -- REPLACE SKID CONTROL ECU
OK -- REPLACE STABILIZER CONTROL ECU