Lexus ES: Yaw Rate Sensor discrimination (C1240)
DESCRIPTION
The airbag ECU assembly has a built-in yaw rate and acceleration sensor and detects the vehicle condition using 2 circuits (GL1, GL2).
If the identification ID of the yaw rate and acceleration sensor (airbag ECU assembly) is different to that stored in the skid control ECU (brake booster with master cylinder assembly), DTC C1240 is stored.
| DTC No. | Detection Item | INF Code | DTC Detection Condition | Trouble Area | MIL | Note |
|---|---|---|---|---|---|---|
| C1240 | Yaw Rate Sensor discrimination | 406 | The identification ID sent from the yaw rate sensor is different to that stored in the skid control ECU (brake booster with master cylinder assembly) for 1 second or more. |
| Comes on |
|
MONITOR DESCRIPTION
When an incompatible yaw rate and acceleration sensor (airbag ECU assembly) is installed and the skid control ECU (brake booster with master cylinder assembly) receives a signal differing from the yaw rate and acceleration sensor that should be installed, the skid control ECU (brake booster with master cylinder assembly) judges that the signal is abnormal and illuminates the MIL and stores this DTC.
MONITOR STRATEGY
| Related DTCs | C1240: Yaw rate and acceleration sensor incorrect |
| Required Sensors/Components(Main) | Yaw rate and acceleration sensor (airbag ECU assembly) |
| Required Sensors/Components(Related) | Skid control ECU (brake booster with master cylinder assembly) |
| Frequency of Operation | Continuous |
| Duration | 1 second |
| MIL Operation | Immediately |
| Sequence of Operation | None |
TYPICAL ENABLING CONDITIONS
| Monitor runs whenever the following DTCs are not stored | None |
| Lost communication with yaw rate and acceleration sensor (airbag ECU assembly) | Not detected |
TYPICAL MALFUNCTION THRESHOLDS
| Yaw rate and acceleration sensor ID (CAN communication data) | Not "4" |
COMPONENT OPERATING RANGE
| Yaw rate and acceleration sensor ID (CAN communication data) | "4" |
CONFIRMATION DRIVING PATTERN
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
- Turn the power switch off.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Wait 1 second.
- Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.
-
Read the DTCs.
HINT:
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.
-
If the DTCs are not output, perform a universal trip and check for permanent DTCs.
Click here
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HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTCs are output, the system is normal.
CAUTION / NOTICE / HINT
NOTICE:
-
After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".
Click here
-
After replacing or reinstalling the yaw rate and acceleration sensor (airbag ECU assembly), perform yaw rate and acceleration sensor zero point calibration after clearing previously calibrated data.
Click here
PROCEDURE
| 1. | CHECK PART NUMBER (AIRBAG ECU ASSEMBLY) |
(a) Check that the proper yaw rate and acceleration sensor (airbag ECU assembly) is installed.
OK:
Proper yaw rate and acceleration sensor (airbag ECU assembly) is installed.
| NG | .gif) | REPLACE AIRBAG ECU ASSEMBLY |
|
| 2. | RECONFIRM DTC |
(a) Clear the DTCs.
Click here
(b) Turn the power switch off.
(c) Turn the power switch on (IG).
(d) Check if the same DTC is output.
Click here
| Result | Proceed to |
|---|---|
| DTC C1240 is output. | A |
| DTC C1240 is not output. | B |
| A | | REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY |
| B | | USE SIMULATION METHOD TO CHECK |
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