ACTIVE HEIGHT CONTROL SUSPENSION, Diagnostic DTC:C1715, C1716, C1717, C1796, C1797, C1798

DTC Code DTC Name
C1715 Front Acceleration Sensor RH Malfunction
C1716 Front Acceleration Sensor LH Malfunction
C1717 Rear Acceleration Sensor Malfunction
C1796 Front Acceleration Sensor RH Malfunction (Test Mode DTC)
C1797 Front Acceleration Sensor LH Malfunction (Test Mode DTC)
C1798 Rear Acceleration Sensor Malfunction (Test Mode DTC)

DESCRIPTION

The acceleration sensor (up and down G sensor) detects the upward and downward acceleration of the vehicle, and outputs it as a voltage to the suspension control ECU. Up and down G sensors are installed in 3 locations: 1) the suspension control ECU, 2) the driver side instrument panel, and 3) the passenger side instrument panel. Each up and down G sensor independently detects the upward and downward acceleration. During a test mode inspection, the suspension control ECU reads the fluctuations in the signal of each sensor. When the sensor cannot detect +/-1.96 m/s2for 1 second or more during test mode, DTCs C1796, C1797 and C1798 are stored.

DTC Code Detection Condition Trouble Area

C1715

C1796

When either of the following conditions is met:


  • With the engine switch on (IG), a voltage of 4.7 V or higher, or 0.3 V or less at the front acceleration sensor RH is detected for 1 second.

  • When there is a front acceleration sensor RH power supply voltage malfunction.

  • Harness or connector

  • Front acceleration sensor RH

  • Suspension control ECU

C1716

C1797

When either of the following conditions is met:


  • With the engine switch on (IG), a voltage of 4.7 V or higher, or 0.3 V or less at the front acceleration sensor LH is detected for 1 second.

  • When there is a front acceleration sensor LH power supply voltage malfunction.

  • Harness or connector

  • Front acceleration sensor LH

  • Suspension control ECU

C1717

C1798

When either of the following conditions is met:


  • With the engine switch on (IG), a voltage of 4.7 V or higher, or 0.3 V or less at the rear acceleration sensor is detected for 1 second.

  • When there is a rear acceleration sensor power supply voltage malfunction.

 Suspension control ECU (Houses rear acceleration sensor)

WIRING DIAGRAM

A01EQG3E02

INSPECTION PROCEDURE

Note


  • Before performing troubleshooting, inspect the connectors of related circuits.

  • If the suspension control ECU or height control sensor is replaced, the vehicle height offset calibration must be performed Click here.

  • If DTCs C1717 and C1798 (Rear Acceleration Sensor Malfunction) are stored, replace the suspension control ECU (houses rear acceleration sensor).

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (ACCELERATION SENSOR)


    1. Turn the engine switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the engine switch on (IG) and the intelligent tester on.

    4. Enter the following menus: Chassis / AHC / Data List.

    5. According to the display on the intelligent tester, read the Data List.

      AHC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      (Up&Down)G Sensor FR

      G (up and down) front acceleration sensor RH reading/

      min.: -1045.29 m/s2

      max.: 1045.26 m/s2

      0 +/-0.98 m/s2at still condition

      		 The reading changes when the vehicle (FR) is bounced.
      (Up&Down)G Sensor FL

      G (up and down) front acceleration sensor LH reading/

      min.: -1045.29 m/s2

      max.: 1045.26 m/s2

      0 +/-0.98 m/s2at still condition

      		 The reading changes when the vehicle (FL) is bounced.
      (Up&Down)G Sensor Rear

      G (up and down) rear acceleration sensor reading/

      min.: -1045.29 m/s2

      max.: 1045.26 m/s2

      0 +/-0.98 m/s2at still condition

      		 The reading changes when the vehicle (rear) is bounced.
      OK
      Reading changes when vehicle is bounced.

    NG

    CHECK HARNESS AND CONNECTOR (ACCELERATION SENSOR - SUSPENSION CONTROL ECU) Click here

    OK

  2. RECONFIRM DTC OUTPUT


    1. Clear the DTCs Click here.

    2. Perform a road test.

    3. Check for DTCs.

      Result
      Result Proceed to
      DTC is output A
      DTC is not output B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  3. CHECK HARNESS AND CONNECTOR (ACCELERATION SENSOR - SUSPENSION CONTROL ECU)

    Note

    When inspecting the wire harnesses between the suspension control ECU and acceleration sensors, it is difficult to determine the malfunctioning area if there is a sensor power supply malfunction. Therefore, disconnect the connectors for the acceleration sensors (front RH, front LH), the fluid temperature sensor, and fluid pressure sensor on the ECU side.


    1. Check the front acceleration sensor RH side: (C1715)

      A01EN5EE04

      1. Disconnect the K30 and K31 ECU connectors.

      2. Disconnect the L43 sensor connector.

      3. Measure the resistance according to the value(s) in the table below.

        Standard Resistance
        Tester Connection Condition Specified Condition
        L43-1 (SGFR) - K30-24 (SGFR) Always Below 1 Ω
        L43-2 (SGG) - K30-14 (SGG1) Always Below 1 Ω
        L43-3 (SGB) - K30-15 (SGB1) Always Below 1 Ω
        K30-24 (SGFR) - Body ground Always 10 kΩ or higher
        K30-14 (SGG1) - Body ground Always 10 kΩ or higher
        K30-15 (SGB1) - Body ground Always 10 kΩ or higher

    2. Check the front acceleration sensor LH side: (C1716)


      1. Disconnect the K30 and K31 ECU connectors.

      2. Disconnect the K33 sensor connector.

        A01EN5EE05

      3. Measure the resistance according to the value(s) in the table below.

        Standard Resistance
        Tester Connection Condition Specified Condition
        K33-1 (SGFL) - K30-22 (SGFL) Always Below 1 Ω
        K33-2 (SGG) - K30-13 (SGG2) Always Below 1 Ω
        K33-3 (SGB) - K30-23 (SGB2) Always Below 1 Ω
        K30-22 (SGFL) - Body ground Always 10 kΩ or higher
        K30-13 (SGG2) - Body ground Always 10 kΩ or higher
        K30-23 (SGB2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT ACCELERATION SENSOR

    A01ENE2E01

    1. Turn the engine switch off.

    2. Remove the front acceleration sensor Click here.

      Note

      Do not drop the acceleration sensor. If it is dropped, replace it with a new one.

    3. Connect 3 1.5 V dry cell batteries in series.

    4. Connect the positive (+) end of the batteries to terminal 3 (SGB) of the acceleration sensor and the negative (-) end of the batteries to terminal 2 (SGG). Then measure the voltage between terminal 1 (SGFR*1, SGFL*2) and terminal 2 (SGG).

      Tech Tips

      *1: for RH

      *2: for LH

      Note

      Do not apply a voltage of more than 6 V.

      Tech Tips

      The voltage may differ according to the amount that the sensor is tilted.

      Standard Voltage
      for RH
      Tester Connection Condition Specified Condition
      1 (SGFR) - 2 (SGG) Sensor stationary Approx. 2.0 to 2.5 V
      Sensor is tilted Change between approx. 0.9 to 2.3 V
      for LH
      Tester Connection Condition Specified Condition
      1 (SGFL) - 2 (SGG) Sensor stationary Approx. 2.0 to 2.5 V
      Sensor is tilted Change between approx. 0.9 to 2.3 V

    NG

    REPLACE ACCELERATION SENSOR Click here

    OK

    REPLACE SUSPENSION CONTROL ECU Click here