DESCRIPTION
If the communication line (EFIO-IMI) to the transponder key ECU assembly is stuck high (e.g. shorted to +B), the ECM stores this DTC.
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
Note |
---|---|---|---|---|
B279A |
Theft Deterrent System Communication Line High Fixation |
Communication line (EFIO-IMI) between the ECM and transponder key ECU assembly is stuck high. |
|
|
Vehicle Condition when Malfunction Detected |
Fail-safe Operation when Malfunction Detected |
---|---|
Engine cannot be started (initial ignition occurs and engine cranks, then ignition stops) |
Engine cannot be started |
DTC No. |
Data List and Active Test |
---|---|
B279A |
- |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Click here
PROCEDURE
1. |
CLEAR DTC |
(a) Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs
|
2. |
CHECK FOR DTC |
(a) Check for DTCs.
Powertrain > Engine and ECT > Trouble CodesHINT:
Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.
OK:
DTC B279A is not output.
Result |
Proceed to |
---|---|
B279A is not output |
A |
B279A is output |
B |
A | ![]() |
USE SIMULATION METHOD TO CHECK |
|
3. |
CHECK CONNECTION OF CONNECTOR |
(a) Check that the connectors are properly connected to the ECM and transponder key ECU assembly.
OK:
Connectors are properly connected.
NG | ![]() |
CONNECT CONNECTORS PROPERLY |
|
4. |
CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - ECM AND BODY GROUND) |
(a) Disconnect the F22 transponder key ECU assembly connector
(b) Disconnect the A38 ECM connector
(c) Measure the resistance according to the value(s) in the table below
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
F22-13 (EFIO) - A38-28 (IMI) |
Always |
Below 1 Ω |
F22-13 (EFIO) - Body ground |
Always |
10 kΩ or higher |
A38-28 (IMI) - Body ground |
Always |
10 kΩ or higher |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
5. |
REPLACE TRANSPONDER KEY ECU ASSEMBLY |
(a) Replace the transponder key ECU assembly with a new one.
Click here
|
6. |
CLEAR DTC |
(a) Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs
|
7. |
CHECK FOR DTC |
(a) Check for DTCs.
Powertrain > Engine and ECT > Trouble CodesHINT:
Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.
OK:
DTC B279A is not output.
Result |
Proceed to |
---|---|
B279A is not output |
A |
B279A is output |
B |
A | ![]() |
END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE) |
B | ![]() |
REPLACE ECM |
Toyota CH-R Service Manual > Continuously Variable Transaxle System: Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
Continuously Variable Transaxle System
DTC No.
Detection Item
MIL
Memory
Link
P0705
Transmission Range Sensor Circuit (PRNDL Input)
Comes on
DTC stored
...
Toyota CH-R Owners Manual > Do-it-yourself maintenance: Wireless remote control/electronic key battery
Replace the battery with a new one if it is depleted.
You will need the following items:
Flathead screwdriver
Small flathead screwdriver
Lithium battery
Vehicles without a smart key system: CR1620
Vehicles with a smart key system: CR2032
Replacing the battery
Vehicles without a smart ...