Toyota Tacoma 2015-2018 Service Manual: Lost Communication with ECM (C1437)
DESCRIPTION
The skid control ECU (brake actuator assembly) receives signals from the ECM via the CAN communication system.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
|---|---|---|---|
|
C1437 |
Lost Communication with ECM |
When voltage at terminal +BS is 10 to 17.4 V and vehicle speed is 15 km/h (9 mph) or more, data cannot be sent to ECM continuously for 2 seconds or more. |
|
CAUTION / NOTICE / HINT
NOTICE:
When replacing the skid control ECU (brake actuator assembly), perform zero point
calibration and store system information (See page
.gif)
).
PROCEDURE
|
1. |
CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION) |
(a) Using the Techstream, check for any momentary interruption in the wire harness
and connector corresponding to the DTC (See page
).
|
Tester Display |
Measurement Item |
Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|---|
|
EFI Communication Open |
EFI communication open detection |
Normal or Error |
Normal |
Error: Momentary interruption |
|
EFI Communication Invalid |
ECM communication invalid detection |
Normal or Error |
Normal |
Error: Invalid |
HINT:
Perform the above inspection before removing the sensor and connector.
OK:
Normal (There are no momentary interruptions.)
| NG | .gif) |
CHECK CAN COMMUNICATION SYSTEM |
|
.gif)
|
2. |
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 15 km/h (9 mph) or more for 10 seconds or more.
(e) Check that no CAN communication system DTC is output (See page
).
(f) Check if the same DTC is recorded (See page
).
|
Result |
Proceed to |
|---|---|
|
DTC C1437 is not output |
A |
|
DTC C1437 is output |
B |
|
CAN communication system DTC is output |
C |
| A | |
USE SIMULATION METHOD TO CHECK |
| B | |
REPLACE BRAKE ACTUATOR ASSEMBLY |
| C | |
CHECK CAN COMMUNICATION SYSTEM |
Yaw Rate Sensor Malfunction (C1436)
DESCRIPTION
The skid control ECU (brake actuator assembly) receives signals from the yaw
rate and acceleration sensor (airbag sensor assembly) via the CAN communication
system.
The airbag sensor ...
Steering Angle Sensor Initialization Incomplete (C1439,C1445)
DESCRIPTION
The skid control ECU (brake actuator assembly) acquires steering angle sensor
zero point every time the ignition switch is turned ON and the vehicle is driven
at 35 km/h (22 mph) or m ...
Other materials:
Brake Control Signal Mismatch (C1A69)
DESCRIPTION
The skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake
actuator assembly)*2 sends signals to the millimeter wave radar sensor assembly
according to the brake control status. If the millimeter wave radar sensor assembly
receives a vehicle stability control sys ...
On-vehicle Inspection
ON-VEHICLE INSPECTION
PROCEDURE
1. INSPECT SPEEDOMETER
(a) Check speedometer operation.
NOTICE:
The meter ECU receives the vehicle speed signal from the skid control
ECU via CAN communication. Therefore, perform the following inspection referring
to values on the Data List of th ...
Slip Indicator Light does not Come ON
DESCRIPTION
Refer to Slip Indicator Light Remains ON (See page
).
WIRING DIAGRAM
Refer to Slip Indicator Light Remains ON (See page
).
CAUTION / NOTICE / HINT
NOTICE:
When replacing the skid control ECU (master cylinder solenoid), perform
calibration (See page
).
Inspe ...
