Lexus ES: Left Front Wheel Speed Sensor Internal Electronic Failure (C050049)
DESCRIPTION
When the system is starting up and the skid control ECU (brake actuator assembly) detects a speed sensor circuit malfunction via the speed sensor circuit self-diagnosis function, this DTC is stored.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| C050049 | Left Front Wheel Speed Sensor Internal Electronic Failure | A circuit malfunction in the speed sensor is detected during the self test. |
|
*: w/ AVS
WIRING DIAGRAM
Refer to DTC C050012.
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CAUTION / NOTICE / HINT
NOTICE:
-
After replacing the skid control ECU (brake actuator assembly), perform acceleration sensor zero point calibration and store system information memorization.
Click here
-
After replacing or removing and installing a speed sensor, perform Dealer Mode (Signal Check) inspection to confirm that the speed sensors are operating correctly.
Click here
PROCEDURE
| 1. | CHECK VEHICLE |
(a) Check if the vehicle is equipped with AVS.
| Result | Proceed to |
|---|---|
| w/o AVS | A |
| w/ AVS | B |
| B |  | GO TO STEP 10 |
|
| 2. | CHECK HARNESS AND CONNECTOR (SENSOR CIRCUIT) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A48 front speed sensor LH connector.
(c) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(d) Turn the engine switch on (IG).
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A48-1 (FL+) - A48-2 (FL-) | Engine switch on (IG) | 11 to 14 V |
| NG | | GO TO STEP 6 |
|
| 3. | CHECK HARNESS AND CONNECTOR (SENSOR POWER SOURCE CIRCUIT) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A48 front speed sensor LH connector.
(c) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A48-1 (FL+) - Body ground | Engine switch off | Below 1.5 V |
| NG | | GO TO STEP 5 |
|
| 4. | CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR LH - BRAKE ACTUATOR ASSEMBLY) |
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
OK:
The connector is securely connected.
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A48 front speed sensor LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A48-2 (FL-) or A40-7 (FL-) - Body ground | Always | 10 kΩ or higher |
| OK | | REPLACE FRONT SPEED SENSOR LH |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 5. | CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR LH - BRAKE ACTUATOR ASSEMBLY) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A48 front speed sensor LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A48-1 (FL+) - Body ground | Always | Below 1.5 V |
| OK | | REPLACE BRAKE ACTUATOR ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 6. | CHECK HARNESS AND CONNECTOR (SENSOR POWER SOURCE CIRCUIT) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A48 front speed sensor LH connector.
(c) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(d) Turn the engine switch on (IG).
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A48-1 (FL+) - Body ground | Engine switch on (IG) | 11 to 14 V |
| NG | | GO TO STEP 9 |
|
| 7. | CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR LH - BRAKE ACTUATOR ASSEMBLY) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A48 front speed sensor LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A48-2 (FL-) - Body ground | Always | Below 1.5 V |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 8. | CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR LH - BRAKE ACTUATOR ASSEMBLY) |
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
OK:
The connector is securely connected.
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A48 front speed sensor LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A48-2 (FL-) - A40-7 (FL-) | Always | Below 1 Ω |
| A48-1 (FL+) or A40-24 (FL+) - A48-2 (FL-) - A40-7 (FL-) | Always | 10 kΩ or higher |
| OK | | REPLACE BRAKE ACTUATOR ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 9. | CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR LH - BRAKE ACTUATOR ASSEMBLY) |
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
OK:
The connector is securely connected.
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A48 front speed sensor LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A48-1 (FL+) - A40-24 (FL+) | Always | Below 1 Ω |
| A48-1 (FL+) or A40-24 (FL+) - Body ground | Always | 10 kΩ or higher |
| OK | | REPLACE BRAKE ACTUATOR ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 10. | CHECK HARNESS AND CONNECTOR (SENSOR CIRCUIT) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the z24 skid control sensor wire with suspension control LH connector.
(c) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(d) Turn the engine switch on (IG).
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| z24-1 (FL+) - z24-2 (FL-) | Engine switch on (IG) | 11 to 14 V |
| NG | | GO TO STEP 16 |
|
| 11. | CHECK HARNESS AND CONNECTOR (SENSOR POWER SOURCE CIRCUIT) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the z24 skid control sensor wire with suspension control LH connector.
(c) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| z24-1 (FL+) - Body ground | Engine switch off | Below 1.5 V |
| NG | | GO TO STEP 14 |
|
| 12. | INSPECT SKID CONTROL SENSOR WIRE WITH SUSPENSION CONTROL LH |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the z24 skid control sensor wire with suspension control LH connector.
(c) Disconnect the A42 skid control sensor wire with suspension control LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| z24-2 (FL-) or A42-5 (FL-) - Body ground and other terminals | Always | 10 kΩ or higher |
| NG | | REPLACE SKID CONTROL SENSOR WIRE WITH SUSPENSION CONTROL LH |
|
| 13. | CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE WITH SUSPENSION CONTROL LH - BRAKE ACTUATOR ASSEMBLY) |
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
OK:
The connector is securely connected.
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A42 skid control sensor wire with suspension control LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A42-5 (FL-) or A40-7 (FL-) - Body ground | Always | 10 kΩ or higher |
| OK | | REPLACE FRONT SPEED SENSOR LH |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 14. | CHECK HARNESS AND CONNECTOR (SENSOR POWER SOURCE CIRCUIT) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A42 skid control sensor wire with suspension control LH connector.
(c) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A42-6 (FL+) - Body ground | Engine switch off | Below 1.5 V |
| OK | | REPLACE SKID CONTROL SENSOR WIRE WITH SUSPENSION CONTROL LH |
|
| 15. | CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE WITH SUSPENSION CONTROL LH - BRAKE ACTUATOR ASSEMBLY) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A42 skid control sensor wire with suspension control LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A42-6 (FL+) - Body ground | Always | Below 1.5 V |
| OK | | REPLACE BRAKE ACTUATOR ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 16. | CHECK HARNESS AND CONNECTOR (SENSOR CIRCUIT) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A42 skid control sensor wire with suspension control LH connector.
(c) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(d) Turn the engine switch on (IG).
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A42-6 (FL+) - A42-5 (FL-) | Engine switch on (IG) | 11 to 14 V |
| OK | | REPLACE SKID CONTROL SENSOR WIRE WITH SUSPENSION CONTROL LH |
|
| 17. | CHECK HARNESS AND CONNECTOR (SENSOR POWER SOURCE CIRCUIT) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A42 skid control sensor wire with suspension control LH connector.
(c) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(d) Turn the engine switch on (IG).
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A42-6 (FL+) - Body ground | Engine switch on (IG) | 11 to 14 V |
| NG | | GO TO STEP 20 |
|
| 18. | CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE WITH SUSPENSION CONTROL LH - BRAKE ACTUATOR ASSEMBLY) |
| (a) Make sure that there is no looseness at the locking part and the connecting part of the connectors. OK: The connector is securely connected. |
|
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A42 skid control sensor wire with suspension control LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A42-5 (FL-) - Body ground | Always | Below 1.5 V |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 19. | CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE WITH SUSPENSION CONTROL LH - BRAKE ACTUATOR ASSEMBLY) |
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
OK:
The connector is securely connected.
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A42 skid control sensor wire with suspension control LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A42-5 (FL-) - A40-7 (FL-) | Always | Below 1 Ω |
| A42-6 (FL+) or A40-24 (FL+) - A42-5 (FL-) or A40-7 (FL-) | Always | 10 kΩ or higher |
| OK | | REPLACE BRAKE ACTUATOR ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 20. | CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE WITH SUSPENSION CONTROL LH - BRAKE ACTUATOR ASSEMBLY) |
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
OK:
The connector is securely connected.
(b) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(c) Disconnect the A42 skid control sensor wire with suspension control LH connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A42-6 (FL+) - A40-24 (FL+) | Always | Below 1 Ω |
| A42-6 (FL+) or A40-24 (FL+) - Body ground | Always | 10 kΩ or higher |
| OK | | REPLACE BRAKE ACTUATOR ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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