DESCRIPTION
If the communication line (EFIO-IMI) to the ID code box is stuck on HI output, the ECM stores this DTC.
DTC Code |
DTC Detection Condition |
Trouble Area |
---|---|---|
B279A |
The communication line (EFIO-IMI) between the ECM and the ID code box is stuck on HI output. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
PROCEDURE
1. |
CLEAR DTC |
(a) Clear the DTCs (See page ).
|
2. |
CHECK FOR DTC |
(a) Check for DTCs (See page ).
HINT:
If DTCs other than DTC B279A are output, troubleshoot those DTCs first.
Result
Result |
Proceed to |
---|---|
DTC B279A is not output |
A |
DTC B279A and other DTCs are output |
B |
DTC B279A is output |
C |
A |
USE SIMULATION METHOD TO CHECK |
B |
Go to DIAGNOSTIC TROUBLE CODE CHART |
|
3. |
CHECK HARNESS AND CONNECTOR (ID CODE BOX - ECM) |
(a) Disconnect the F72 box connector.
(b) Disconnect the F50 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
F72-6 (EFIO) - F50-14 (IMI) |
Always |
Below 1 Ω |
F72-6 (EFIO) or F50-14 (IMI) - Body ground |
Always |
10 kΩ or higher |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
4. |
CHECK ID CODE BOX (OUTPUT) |
(a) Using an oscilloscope, check the waveform.
Text in Illustration
*a |
Component with harness connected (ECM) |
- |
- |
Item |
Content |
---|---|
Tester Connection |
F50-14 (IMI) - Body ground |
Tool Setting |
10 V/DIV., 100 ms./DIV. |
Condition |
Engine switch on (IG) |
OK:
Waveform is output normally (refer to illustration).
OK |
REPLACE ECM |
|
5. |
CHECK HARNESS AND CONNECTOR (ID CODE BOX - BATTERY AND BODY GROUND) |
(a) Disconnect the F72 box connector. |
|
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
F72-1 (+B) - Body ground |
Always |
11 to 14 V |
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
F72-8 (GND) - Body ground |
Always |
Below 1 Ω |
*a |
Front view of wire harness connector (to ID Code Box) |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
6. |
REPLACE ID CODE BOX |
(a) Replace the ID code box (See page ).
|
7. |
REGISTER RECOGNITION CODES |
(a) Register the recognition codes in the ECUs (See page ).
|
8. |
REGISTER ECU COMMUNICATION ID |
(a) Register the ECU communication ID (See page ).
|
9. |
CLEAR DTC |
(a) Clear the DTCs (See page ).
|
10. |
CHECK FOR DTC |
(a) Check for DTCs (See page ).
OK:
DTC B279A is not output.
OK |
END (ID CODE BOX IS DEFECTIVE) |
NG |
REPLACE ECM |
Precaution
PRECAUTION
1. IGNITION SWITCH EXPRESSION
HINT:
The type of ignition switch used on this model differs according to the specifications
of the vehicle. The expressions listed in the table below are used in this section.
Expression
Ign ...
Horn System
Parts Location
PARTS LOCATION
ILLUSTRATION
Problem Symptoms Table
PROBLEM SYMPTOMS TABLE
HINT:
Use the table below to help determine the cause of problem symptoms. If multiple
suspected areas are listed, the potential causes of the symptoms are l ...