Toyota Tacoma (2015-2018) Service Manual: Steering Angle Sensor Initialization Incomplete (C1439,C1445)
DESCRIPTION
The skid control ECU (master cylinder solenoid) acquires steering angle sensor (spiral cable with sensor sub-assembly) zero point every time the ignition switch is turned to ON and the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds. The ECU also stores the previous zero point.
The steering angle sensor (spiral cable with sensor sub-assembly) zero point malfunction warning will be cancelled by turning the ignition switch to off.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
C1439 |
After the steering angle sensor 0 calibration is cleared due to, for example, fluctuations in the power source, the steering angle 0 calibration cannot be obtained for 0.048 seconds of continuous driving |
|
|
C1445 |
Steering angle sensor 0 calibration cannot be obtained when the vehicle is driven without a record of steering angle sensor 0 calibration at a speed of 36 km/h (22 mph) or more for 30 seconds or more without the brake pedal being depressed |
|
CAUTION / NOTICE / HINT
NOTICE:
- Before proceeding with the inspection, explain to the customer that the output DTC is related to temporary loss of the steering angle zero calibration, such as when the power voltage drops when the battery is removed, and confirm that this condition occurred.
- When replacing the skid control ECU (master cylinder solenoid), perform
calibration (See page
.gif)
).
HINT:
- When DTC U0073, U0123, U0124 and/or U0126 is output together with DTC
C1439 and/or C1445, inspect and repair the trouble areas indicated by DTC
U0073, U0123, U0124 and/or U0126 first (See page
).
- When the speed sensor or the yaw rate and acceleration sensor (airbag sensor assembly) has trouble, DTCs for the steering angle sensor (spiral cable with sensor sub-assembly) may be stored even when the steering angle sensor (spiral cable with sensor sub-assembly) is normal. When DTCs for the speed sensor or yaw rate and acceleration sensor (airbag sensor assembly) are output together with other DTCs for the steering angle sensor (spiral cable with sensor sub-assembly), inspect and repair the speed sensor and yaw rate and acceleration sensor (airbag sensor assembly) first, and then inspect and repair the steering angle sensor (spiral cable with sensor sub-assembly).
PROCEDURE
|
1. |
CHECK DTC |
(a) Clear the DTCs (See page
).
(b) Turn the ignition switch off.
(c) Turn the ignition switch to ON again and check that no CAN communication
system DTC is output (See page
).
(d) Drive the vehicle at a speed of 35 km/h (22 mph) and turn the steering wheel
to the right and left, and then check that no speed sensor and yaw rate and acceleration
sensor (airbag sensor assembly) DTCs are output (See page
).
|
Result |
Proceed to |
|
|---|---|---|
|
DTC is output |
C1439 and/or C1445 |
A |
|
Relating to CAN communication system |
B |
|
|
Relating to speed sensor or yaw rate and acceleration sensor |
C |
|
|
DTC is not output |
D |
|
HINT:
- If there is a malfunction in the speed sensor or the yaw rate and acceleration sensor (airbag sensor assembly), an abnormal value may be output although the steering angle sensor (spiral cable with sensor sub-assembly) is normal.
- If the speed sensor and the yaw rate and acceleration sensor (airbag sensor assembly) DTCs are output simultaneously, repair the sensors and inspect the steering angle sensor (spiral cable with sensor sub-assembly).
- If DTC C1439 and/or C1445 is not output again, the DTC may have been stored due to a temporary loss of the steering angle zero calibration, such as when the power voltage drops.
| B | .gif) |
GO TO COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) |
| C | |
REPAIR CIRCUITS INDICATED BY OUTPUT DTCS |
| D | |
USE SIMULATION METHOD TO CHECK |
|
.gif)
|
2. |
PERFORM STEERING ANGLE SENSOR ZERO POINT CALIBRATION |
(a) Drive the vehicle straight ahead at 35 km/h (22 mph) or more for at least 5 seconds.
(b) Check that the centered position of the steering wheel is correctly set while driving straight ahead.
HINT:
If the front wheel alignment and steering position are adjusted as a result of an abnormal centered position of the steering wheel, acquire the yaw rate and acceleration sensor zero point again after the adjustments are completed.
OK:
The centered position of the steering wheel is correctly set.
| NG | |
ADJUST FRONT WHEEL ALIGNMENT OR STEERING POSITION |
|
|
3. |
RECONFIRM DTC |
(a) Clear the DTCs (See page
).
(b) Turn the ignition switch off.
(c) Start the engine.
(d) Drive the vehicle at a speed of 35 km/h (22 mph) or more and turn the steering wheel to the right and left.
(e) Check if the same DTC is output (See page
).
|
Result |
Proceed to |
|---|---|
|
DTCs C1439 and C1445 are not output |
A |
|
Yaw rate and acceleration sensor and/or steering angle sensor DTC is output |
B |
HINT:
If DTC C1439 and/or C1445 is not output again, the DTC may have been stored due to a temporary loss of the steering angle zero calibration, such as when the power voltage drops.
| A | |
END |
| B | |
REPAIR CIRCUITS INDICATED BY OUTPUT DTCS |
Lost Communication with ECM (C1437)
DESCRIPTION
The skid control ECU (master cylinder solenoid) receives signals from the ECM
via the CAN communication system.
DTC Code
DTC Detection Condition
Troubl ...
Steering Angle Sensor Unusual Bank Angle Detected (C1440)
DESCRIPTION
If the skid control ECU (master cylinder solenoid) determines that the vehicle
is being driven at a steep bank angle, the skid control ECU (master cylinder solenoid)
stores DTC C1440 ...
Other materials:
If the engine will not start
If the engine still does not start after following the correct starting procedure
(→P. 141) or releasing the steering lock (→P. 142), confirm the following points.
■ The engine will not start even when the starter motor operates normally.
One of the following may be the cause o ...
Inspection
INSPECTION
PROCEDURE
1. INSPECT CYLINDER BLOCK FOR WARPAGE
(a) Using a precision straightedge and feeler gauge, measure the warpage
of the contact surface of the cylinder head gasket.
Standard warpage:
0 to 0.05 mm (0 to 0.00197 in.)
Maximum warpage:
0.07 mm (0.00276 ...
Disassembly
DISASSEMBLY
PROCEDURE
1. REMOVE CONNECTOR COVER
(a) Disengage the 2 clips to remove the connector cover.
2. REMOVE REAR BUMPER PAD SUB-ASSEMBLY
(a) Separate the 2 license plate light assemblies as shown in the illustration.
...
