C1796

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM (w/ AVS): C1715-C1717,C1796-C1798: Front Acceleration Sensor RH Malfunction
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 each sensor's signal. If a sensor's signal does not fluctuate, test mode DTCs C1796, C1797 and C1798 are output.

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

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (G SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON, and turn the Techstream main switch on.

(c) Enter the following menus: Chassis / Air suspension / Data List.

Air Suspension

OK:

Acceleration value changes.

NG -- INSPECT ACCELERATION SENSOR (FRONT LH OR RH)

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

2. INSPECT ACCELERATION SENSOR (FRONT LH OR RH)

(a) Turn the ignition switch off.

(b) Check the acceleration sensor RH: (C1715, C1796).

(1) Remove the acceleration sensor RH Removal.

(2) Connect 3 dry cell batteries of 1.5 V in series.

(3) Connect the positive (+) end of the batteries to terminal 3 (SHB) of the acceleration sensor and the negative (-) end of the batteries to terminal 2 (SHG). Then measure the voltage between terminal 1 (SGFL) and terminal 2 (SHG).

(4) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

(1) Remove the acceleration sensor LH Removal.

(2) Connect 3 dry cell batteries of 1.5 V in series.

(3) Connect the positive (+) end of the batteries to terminal 3 (SGV) of the acceleration sensor and the negative (-) end of the batteries to terminal 2 (SGND). Then measure the voltage between terminal 1 (SGRR) and terminal 2 (SGND).

(4) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

NOTICE:
Do not apply a voltage of more than 6 V.

HINT
When the acceleration sensor is tilted, it may output a different value.

Result

C -- REPLACE FRONT ACCELERATION SENSOR LH Removal

B -- REPLACE FRONT ACCELERATION SENSOR RH Removal
A -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (FRONT ACCELERATION SENSOR - ECU AND BODY GROUND)

(a) Check the acceleration sensor RH: (C1715, C1796).

(1) Disconnect the O17 and O18 ECU connector.

(2) Disconnect the H74 sensor connector.

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

Standard Resistance:

(b) Check the acceleration sensor LH: (C1716, C1797).

(1) Disconnect the O17 and O18 ECU connector.

(2) Disconnect the H75 sensor connector.

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

Standard Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE SUSPENSION CONTROL ECU Removal