Toyota 4Runner: Lost Communication with ECM (C1437)
DESCRIPTION
The skid control ECU 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 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 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
Refer to DTC C1419 and C1435 (See page ).
DTC Code
DTC Detection Condition
Trouble Area
C1436
Either condition is met:
...
Steering Angle Sensor Initialization Incomplete (C1439,C1445)
DESCRIPTION
The skid control ECU acquires steering angle sensor zero point every time the
ignition switch is turned to ON and the vehicle is driven at 40 km/h (25 mph) or
more for approximately 1 ...
Other materials about Toyota 4Runner:
On-vehicle Inspection
ON-VEHICLE INSPECTION
PROCEDURE
1. CHECK FRONT SEAT SIDE AIRBAG ASSEMBLY (VEHICLE NOT INVOLVED IN COLLISION)
(a) Perform a diagnostic system check (See page
).
(b) With the front seat side airbag installed on the vehicle, perform a visual
check. If the ...
Back Sonar Sensor LH Circuit
DESCRIPTION
The ultrasonic sensor sends and receives ultrasonic waves. Based on the received
wave, the sensor calculates the approximate distance between the vehicle and the
obstacle, and sends the distance value as a signal to the clearance warning ECU
...
0.0137