Toyota Tacoma (2015-2018) Service Manual: 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 |
Trouble Area |
|---|---|---|
|
C1437 |
When the IG1 terminal voltage is 10 V or higher and the vehicle speed is 15 km/h (9 mph) or more, data cannot be sent from the ECM for 2 seconds or more. |
|
CAUTION / NOTICE / HINT
NOTICE:
When replacing the skid control ECU (master cylinder solenoid), perform calibration
(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/ Error or Normal |
Normal |
- |
OK:
Normal (there are no momentary interruptions).
HINT:
Perform the above inspection before removing the sensor and connector.
| NG | .gif) |
GO TO STEP 3 |
|
.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 output (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 | |
GO TO ENGINE CONTROL SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) |
| C | |
GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) |
|
3. |
REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU - ECM) |
(a) Turn the ignition switch off.
(b) Repair or replace the harness or connector.
(c) Check for any momentary interruption between the skid control ECU (master
cylinder solenoid) and ECM (See page ).
(d) Check that there is no momentary interruption.
|
|
4. |
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 output (See page
).
|
Result |
Proceed to |
|---|---|
|
DTC C1437 is not output |
A |
|
DTC C1437 is output |
B |
|
CAN communication system DTC is output |
C |
| A | |
END |
| B | |
REPLACE MASTER CYLINDER SOLENOID |
| C | |
GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) |
Yaw Rate Sensor Malfunction (C1436)
DESCRIPTION
The skid control ECU (master cylinder solenoid) receives signals from the yaw
rate and acceleration (airbag sensor assembly) via the CAN communication system.
The airbag sensor assembl ...
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 th ...
Other materials:
Cruise Control Switch Circuit
DESCRIPTION
The cruise control main switch is used to turn the dynamic radar cruise control
system on and off, as well as operate 7 functions: SET, - (COAST), TAP-DOWN, RES
(RESUME), + (ACCEL), TAP-UP and CANCEL.
The SET, TAP-DOWN and - (COAST) functions, and the RES (RESUME), TAP-UP and +
( ...
Disassembly
DISASSEMBLY
CAUTION / NOTICE / HINT
HINT:
Use the same procedures for both the LH and RH sides.
The procedure described below is for the LH side.
PROCEDURE
1. REMOVE OUTER MIRROR
(a) Push the lower part of the mirror surface and tilt it.
Text in Illustration
...
Steering Angle Sensor Zero Point Malfunction (C1290)
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 more for approximately 5 seconds. The ECU also stores the
previous zero point.
If front wheel alig ...
