- 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.
| Last Modified: 11-27-2007 | 1.6 C | |
| Service Category: Suspension | Section: Suspension Control System | |
| Model Year: 2008 | Model: LX570 | Doc ID: RM000002PE6007X |
| Title: SUSPENSION CONTROL: ACTIVE HEIGHT CONTROL SUSPENSION: DESCRIPTION (2008 LX570) | ||
|
DTC |
C1715 |
Front Acceleration Sensor RH Malfunction |
|
DTC |
C1716 |
Front Acceleration Sensor LH Malfunction |
|
DTC |
C1717 |
Rear Acceleration Sensor Malfunction |
|
DTC |
C1796 |
Front Acceleration Sensor RH Malfunction (Test Mode DTC) |
|
DTC |
C1797 |
Front Acceleration Sensor LH Malfunction (Test Mode DTC) |
|
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/s2 for 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: |
|
|
C1716 C1797 |
When either of the following conditions is met:
|
|
|
C1717 C1798 |
When either of the following conditions is met:
|
Suspension control ECU (Houses rear acceleration sensor) |
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
- 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
.
- 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 TECHSTREAM (ACCELERATION SENSOR) |
(a) Turn the engine switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the engine switch on (IG) and the Techstream on.
(d) Enter the following menus: Chassis / AHC / Data List.
(e) According to the display on the Techstream, 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/s2 at 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/s2 at 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/s2 at still condition |
The reading changes when the vehicle (rear) is bounced. |
OK:
Reading changes when vehicle is bounced.
|
|
2. |
RECONFIRM DTC OUTPUT |
(a) Clear the DTCs
.
(b) Perform a road test.
(c) Check for DTCs.
Result
|
Result |
Proceed to |
|---|---|
|
DTC is output |
A |
|
DTC is not output |
B |
|
|
3. |
CHECK HARNESS AND CONNECTOR (ACCELERATION SENSOR - SUSPENSION CONTROL ECU) |
NOTICE:
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.
(a) Check the front acceleration sensor RH side: (C1715)
(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 |
(b) Check the front acceleration sensor LH side: (C1716)
(1) Disconnect the K30 and K31 ECU connectors.
(2) Disconnect the K33 sensor connector.
(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 |
|
|
4. |
INSPECT ACCELERATION SENSOR |
(a) Turn the engine switch off.
(b) Remove the front acceleration sensor
.
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) 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).
HINT:
*1: for RH
*2: for LH
NOTICE:
Do not apply a voltage of more than 6 V.
HINT:
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 |
|
|
|