Lexus ES: Front Acceleration Sensor RH Malfunction (C1715-C1717,C1796-C1798)

Lexus ES (XZ10) Service Manual / Suspension / Suspension Control / Adaptive Variable Suspension System / Front Acceleration Sensor RH Malfunction (C1715-C1717,C1796-C1798)

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 absorber control ECU.

The 3 up and down G sensors are installed in the driver side instrument panel, the passenger side instrument panel and the absorber control ECU.

Each up and down G sensor independently detects the upward and downward acceleration of the vehicle.

During a test mode inspection, the absorber control ECU reads the fluctuations in each sensor signal.

When a sensor signal does not fluctuate, test mode DTCs C1796, C1797 and C1798 remain stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory
C1715	Front Acceleration Sensor RH Malfunction	One of the following conditions is met: With the engine switch on (IG), a voltage of 5.5 V or more, or 4.3 V or less is detected at the power source of the acceleration sensor assembly RH for 0.5 seconds. With the engine switch on (IG), a voltage of 4.7 V or more, or 0.3 V or less is detected at the acceleration sensor assembly RH for 1 second. Sensor output value is -0.0639 to 0.0639 m/s2 continuously for 300 seconds.	Acceleration sensor assembly RH Wire harness or connector Absorber control ECU	Does not come on	Yes
C1716	Front Acceleration Sensor LH Malfunction	One of the following conditions is met: With the engine switch on (IG), a voltage of 5.5 V or more, or 4.3 V or less is detected at the power source of the acceleration sensor assembly LH for 0.5 seconds. With the engine switch on (IG), a voltage of 4.7 V or more, or 0.3 V or less is detected at the acceleration sensor assembly LH for 1 second. Sensor output value is -0.0639 to 0.0639 m/s2 continuously for 300 seconds.	Acceleration sensor assembly LH Wire harness or connector Absorber control ECU	Does not come on	Yes
C1717	Rear Acceleration Sensor Malfunction	One of the following conditions is met: With the engine switch on (IG), a voltage of 5.5 V or more, or 4.3 V or less is detected at the power source of the rear acceleration sensor (absorber control ECU) for 0.5 seconds. With the engine switch on (IG), a voltage of 4.7 V or more, or 0.3 V or less is detected at the rear acceleration sensor (absorber control ECU) for 1 second. Sensor output value is -0.0639 to 0.0639 m/s2 continuously for 300 seconds.	Absorber control ECU	Does not come on	Yes
C1796	(Up&Down)G Sensor FR	With the vehicle stationary on a level surface, an acceleration sensor value that is within -1.96 to 1.96 m/s2 is not received from the acceleration sensor assembly RH for 1 second or more.	Acceleration sensor assembly RH Wire harness or connector Absorber control ECU	Test mode	(Test mode)
C1797	(Up&Down)G Sensor FL	With the vehicle stationary on a level surface, an acceleration sensor value that is within -1.96 to 1.96 m/s2 is not received from the acceleration sensor assembly LH for 1 second or more.	Acceleration sensor assembly LH Wire harness or connector Absorber control ECU	Test mode	(Test mode)
C1798	(Up&Down)G Sensor Rear	With the vehicle stationary on a level surface, an acceleration sensor value that is within -1.96 to 1.96 m/s2 is not received from the rear acceleration sensor (absorber control ECU) for 1 second or more.	Absorber control ECU	Test mode	(Test mode)

DTC Detection Conditions: C1715

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3	Pattern 4	Pattern 5
Diagnosis Condition	Engine switch is on (IG)	○	○	○	○	○
Malfunction Status	Sensor power source voltage is 4.3 V or less	○	-	-	-	-
	Sensor power source voltage is 5.5 V or more	-	○	-	-	-
	Output voltage is 0.3 V or less	-	-	○	-	-
	Output voltage is 4.7 V or more	-	-	-	○	-
	Sensor output value is -0.0639 to 0.0639 m/s2	-	-	-	-	○
Detection Time		0.5 seconds or more	0.5 seconds or more	1 second or more	1 second or more	300 seconds or more
Number of Trips		1 trip	1 trip	1 trip	1 trip	1 trip

HINT:

DTC will be stored when the conditions of any pattern in the table above are met.

DTC Detection Conditions: C1716

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3	Pattern 4	Pattern 5
Diagnosis Condition	Engine switch is on (IG)	○	○	○	○	○
Malfunction Status	Sensor power source voltage is 4.3 V or less	○	-	-	-	-
	Sensor power source voltage is 5.5 V or more	-	○	-	-	-
	Output voltage is 0.3 V or less	-	-	○	-	-
	Output voltage is 4.7 V or more	-	-	-	○	-
	Sensor output value is -0.0639 to 0.0639 m/s2	-	-	-	-	○
Detection Time		0.5 seconds or more	0.5 seconds or more	1 second or more	1 second or more	300 seconds or more
Number of Trips		1 trip	1 trip	1 trip	1 trip	1 trip

HINT:

DTC will be stored when the conditions of any pattern in the table above are met.

DTC Detection Conditions: C1717

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3	Pattern 4	Pattern 5
Diagnosis Condition	Engine switch is on (IG)	○	○	○	○	○
Malfunction Status	Sensor power source voltage is 4.3 V or less	○	-	-	-	-
	Sensor power source voltage is 5.5 V or more	-	○	-	-	-
	Output voltage is 0.3 V or less	-	-	○	-	-
	Output voltage is 4.7 V or more	-	-	-	○	-
	Sensor output value is -0.0639 to 0.0639 m/s2	-	-	-	-	○
Detection Time		0.5 seconds or more	0.5 seconds or more	1 second or more	1 second or more	300 seconds or more
Number of Trips		1 trip	1 trip	1 trip	1 trip	1 trip

HINT:

DTC will be stored when the conditions of any pattern in the table above are met.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Before performing troubleshooting, inspect the connectors of related circuits.
Before replacing the absorber control ECU, perform all of the following:
- Symptom simulation.
  Click here
- DTC inspection.
  Click here
- Techstream inspection.
  Click here
  - If no malfunctions are found in other areas, replace the absorber control ECU.
After replacing the absorber control ECU with a new one, perform registration of vehicle identification information.
Click here

PROCEDURE

1.	READ VALUE USING TECHSTREAM ((UP & DOWN) G SENSOR)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

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

Chassis > Air suspension > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
(Up&Down)G Sensor FR	Front acceleration sensor RH (up and down)	Min.: -1045.29 m/s2 Max.: 1045.26 m/s2	-0.98 to 0.98 m/s2 when stationary	The value changes when the vehicle (front RH) is bounced.
(Up&Down)G Sensor FL	Front acceleration sensor LH (up and down)	Min.: -1045.29 m/s2 Max.: 1045.26 m/s2	-0.98 to 0.98 m/s2 when stationary	The value changes when the vehicle (front LH) is bounced.
(Up&Down)G Sensor Rear	Rear acceleration sensor (up and down)	Min.: -1045.29 m/s2 Max.: 1045.26 m/s2	-0.98 to 0.98 m/s2 when stationary	The value changes when the vehicle (rear) is bounced.

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

(Up&Down)G Sensor FR

Front acceleration sensor RH (up and down)

Min.: -1045.29 m/s2

Max.: 1045.26 m/s2

-0.98 to 0.98 m/s2

when stationary

The value changes when the vehicle (front RH) is bounced.

(Up&Down)G Sensor FL

Front acceleration sensor LH (up and down)

Min.: -1045.29 m/s2

Max.: 1045.26 m/s2

-0.98 to 0.98 m/s2

when stationary

The value changes when the vehicle (front LH) is bounced.

(Up&Down)G Sensor Rear

Rear acceleration sensor (up and down)

Min.: -1045.29 m/s2

Max.: 1045.26 m/s2

-0.98 to 0.98 m/s2

when stationary

The value changes when the vehicle (rear) is bounced.

Chassis > Air suspension > Data List

Tester Display
(Up&Down)G Sensor FR
(Up&Down)G Sensor FL
(Up&Down)G Sensor Rear

OK:

The values are as specified in the normal condition column.

Result	Proceed to
OK	A
NG (front RH or front LH)	B
NG (rear)	C

GO TO STEP 3

REPLACE ABSORBER CONTROL ECU

2.	CHECK FOR DTCS

(a) Clear the DTCs.

Click here

Chassis > Air suspension > Clear DTCs

(b) Turn the engine switch off.

Click here

Chassis > Air suspension > Trouble Codes

Result	Proceed to
DTCs are output (front RH or front LH)	A
DTCs are output (rear)	B
DTCs are not output	C

REPLACE ABSORBER CONTROL ECU

USE SIMULATION METHOD TO CHECK

3.	INSPECT ACCELERATION SENSOR ASSEMBLY

(a) Turn the engine switch off.

(b) Remove the acceleration sensor assembly RH or acceleration sensor assembly LH.

Click here

Result	Proceed to
OK	A
NG (Acceleration sensor assembly RH malfunction)	B
NG (Acceleration sensor assembly LH malfunction)	C

REPLACE ACCELERATION SENSOR ASSEMBLY RH

REPLACE ACCELERATION SENSOR ASSEMBLY LH

4.	CHECK HARNESS AND CONNECTOR (ACCELERATION SENSOR ASSEMBLY - ABSORBER CONTROL ECU)

(a) Check the acceleration sensor assembly RH harness and connector (when DTC C1715 is output).

(1) Disconnect the N91 acceleration sensor assembly RH connector.

(2) Disconnect the N32 absorber control ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N91-1 (SGFR) - N32-23 (SGS1)	Always	Below 1 Ω
N91-2 (SGG) - N32-22 (SGG1)	Always	Below 1 Ω
N91-3 (SGB) - N32-14 (SGB1)	Always	Below 1 Ω
N91-1 (SGFR) or N32-23 (SGS1) - Body ground	Always	10 kΩ or higher
N91-2 (SGG) or N32-22 (SGG1) - Body ground	Always	10 kΩ or higher
N91-3 (SGB) or N32-14 (SGB1) - Body ground	Always	10 kΩ or higher

(b) Check the acceleration sensor assembly LH harness and connector (when DTC C1716 is output).

(1) Disconnect the A66 acceleration sensor assembly LH connector.

(2) Disconnect the N32 absorber control ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A66-1 (SGFL) - N32-25 (SGS2)	Always	Below 1 Ω
A66-2 (SGG) - N32-24 (SGG2)	Always	Below 1 Ω
A66-3 (SGB) - N32-15 (SGB2)	Always	Below 1 Ω
A66-1 (SGFL) or N32-25 (SGS2) - Body ground	Always	10 kΩ or higher
A66-2 (SGG) or N32-24 (SGG2) - Body ground	Always	10 kΩ or higher
A66-3 (SGB) or N32-15 (SGB2) - Body ground	Always	10 kΩ or higher

REPLACE ABSORBER CONTROL ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

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Lexus ES: Front Acceleration Sensor RH Malfunction (C1715-C1717,C1796-C1798)

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