C1798

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM: C1715-C1717,C1796-C1798: Front Acceleration Sensor RH Malfunction


DESCRIPTION

The acceleration sensor (up & down G sensor) detects the upward and downward acceleration of the vehicle, and outputs it as a voltage to the suspension control ECU. Up & down G sensors are installed in 3 locations: 1) the suspension control ECU, 2) the driver side instrument panel, and 3) the rear quarter. Each up & 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.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
- Before performing troubleshooting, inspect the connectors of related circuits.
- If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first C1782.
- Before replacing the suspension control ECU, perform all of the following again: 1) symptom simulation Electronic Circuit Inspection Procedure; 2) DTC inspection; and 3) the Techstream inspection (Data List or Active Test). If no malfunctions are found in other areas, replace the suspension control ECU.
- If the suspension control ECU or height control sensor is replaced, the vehicle height offset calibration must be performed Programming and Relearning.
- If DTCs C1715 and C1796 (Front Acceleration Sensor RH Malfunction) are output, replace the suspension control ECU (houses front acceleration sensor RH).

PROCEDURE

1. CHECK ACCELERATION SENSOR (DATA LIST)

(a) Turn the power switch OFF.

(b) Connect the Techstream to the DLC3.

(c) Turn the power switch ON (IG) and the Techstream ON.

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

(e) According to the display on the Techstream screen, read the DATA LIST.

Air Suspension





OK:

Acceleration value changes.

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

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

2. INSPECT ACCELERATION SENSOR (FRONT LH OR REAR)





(a) Turn the power switch OFF.

(b) Remove the front acceleration sensor LH Removal or rear acceleration sensor Removal.

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

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

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

HINT
*1: for Front LH

*2: for Rear

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

Standard voltage:

for Front LH: (C1716, C1797)





for Rear: (C1717, C1798)





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 REAR ACCELERATION SENSOR Removal

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

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

(a) Check the front acceleration sensor LH (C1716, C1797).





(1) Disconnect the R1 ECU connector.

(2) Disconnect the L17 sensor connector.

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

Standard resistance:





(b) Check the rear acceleration sensor (C1717, C1798).





(1) Disconnect the R1 ECU connector.

(2) Disconnect the R26 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