Toyota Tacoma 2015-2018 Service Manual: ECM Communication Circuit Malfunction (C1203)
DESCRIPTION
The circuit is used to send TRAC and VSC control information from the skid control ECU (brake actuator assembly) to the ECM, and engine control information from the ECM to the skid control ECU (brake actuator assembly) through the CAN communication system.
for 4WD or w/ Rear Differential Lock:
The rear differential lock identification signal is sent from the 4 wheel drive control ECU to the skid control ECU (brake actuator assembly) via the CAN communication system.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
|---|---|---|---|
|
C1203 |
ECM Communication Circuit Malfunction |
Any of the following is detected:
|
|
- *: for 4WD or w/ Rear Differential Lock
HINT:
DTC will be output when conditions for any of the patterns in the table above are met.
CAUTION / NOTICE / HINT
NOTICE:
When replacing the skid control ECU (brake actuator assembly), perform zero point
calibration and store system information (See page
.gif)
).
HINT:
When DTC C1203, inspect and repair the trouble areas indicated.
PROCEDURE
|
1. |
CHECK PART NUMBER (ECM) |
(a) Check that the proper ECM is installed.
Result|
Result |
Proceed to |
|---|---|
|
Proper ECM is installed (for 4WD or w/ Rear Differential Lock) |
A |
|
Proper ECM is installed (except 4WD or w/o Rear Differential Lock) |
B |
|
Proper ECM are not installed |
C |
| B | .gif) |
GO TO STEP 3 |
| C | |
CHECK OR REPLACE CHARGING SYSTEM OR BATTERY |
|
.gif)
|
2. |
CHECK PART NUMBER (4 WHEEL DRIVE CONTROL ECU) |
(a) Check that a proper 4 wheel drive control ECU is installed.
Result|
Result |
Proceed to |
|---|---|
|
Proper 4 wheel drive control ECU is installed |
A |
|
Proper 4 wheel drive control ECU are not installed |
B |
| B | |
REPLACE 4 WHEEL DRIVE CONTROL ECU |
|
|
3. |
CHECK BRAKE ACTUATOR ASSEMBLY |
(a) Check if the brake actuator assembly had been replaced before the DTC was recorded.
Result|
Result |
Proceed to |
|---|---|
|
The brake actuator assembly is not replaced |
A |
|
The brake actuator assembly is replaced |
B |
| B | |
GO TO STEP 5 |
|
|
4. |
RECONFIRM DTC |
(a) Clear the DTC (See page
).
(b) Turn the ignition switch off.
(c) Check if the same DTC is recorded (See page
).
|
Result |
Proceed to |
|---|---|
|
DTC C1203 is not output |
A |
|
DTC C1203 is output |
B |
| A | |
USE SIMULATION METHOD TO CHECK |
| B | |
REPLACE BRAKE ACTUATOR ASSEMBLY |
|
5. |
PERFORM INITIALIZATION AND CALIBRATION |
(a) Perform initialization and calibration (See page
).
|
|
6. |
RECONFIRM DTC |
(a) Clear the DTC (See page
).
(b) Turn the ignition switch off.
(c) Check if the same DTC is recorded (See page
).
|
Result |
Proceed to |
|---|---|
|
DTC C1203 is not output |
A |
|
DTC C1203 is output |
B |
| A | |
END |
| B | |
REPLACE BRAKE ACTUATOR ASSEMBLY |
Engine Control System Malfunction (C1201)
DESCRIPTION
If a malfunction in the engine control system is detected, VSC and TRAC operations
are prohibited by the fail-safe function.
DTC No.
Detection Item
DTC ...
ABS Warning Light does not Come ON
DESCRIPTION
The skid control ECU (brake actuator assembly) is connected to the combination
meter assembly via CAN communication.
WIRING DIAGRAM
Refer to ABS Warning Light Remains ON (See page
) ...
Other materials:
Tire Pressure Monitor ECU Communication Stop (C2179/79)
DESCRIPTION
The main body ECU (multiplex network body ECU) sends signals to the tire pressure
warning ECU and receiver via a direct line.
DTC No.
Detection Item
DTC Detection Condition
Trouble Area
Note
C2179/79
T ...
Parts Location
PARTS LOCATION
ILLUSTRATION
*A
for Double Cab
*B
for Access Cab
*C
w/ Back Door Power Window
-
-
*1
NO. 1 BACK PANEL RELAY
*2
NO. 2 BACK PANEL RELAY
...
Reassembly
REASSEMBLY
CAUTION / NOTICE / HINT
HINT:
The procedure described below is for the LH side. Use the same procedure for
both the LH and RH sides, unless otherwise specified.
PROCEDURE
1. INSTALL REAR SEAT CUSHION FRAME SUB-ASSEMBLY
(a) Install the rear seat cushion frame sub-assembl ...