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:
Reassembly
REASSEMBLY
CAUTION / NOTICE / HINT
NOTICE:
Do not try to remove the black nylon tube as it is welded to the fuel suction
tube assembly (See page
).
HINT:
Perform "Inspection After Repairs" after replacing the fuel pump (See page
).
PROCEDURE
1. INSTALL FUEL PUMP
HINT:
Perfo ...
On-vehicle Inspection
ON-VEHICLE INSPECTION
PROCEDURE
1. CHECK FUEL PUMP ASSEMBLY OPERATION
(a) Check fuel pressure.
(1) Connect the Techstream to the DLC3.
(2) Start the engine.
(3) Turn the Techstream on.
(4) Enter the following menus: Powertrain / Engine / Active Test / Control the
Target Fuel Pressure.
(5) ...
Freeze Frame Data
FREEZE FRAME DATA
DESCRIPTION
(a) Whenever a lane departure alert system is stored, the forward recognition
camera stores the current vehicle state (ECU and sensor information) as Freeze Frame
Data.
CHECK FREEZE FRAME DATA
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ...