| DTC Code | DTC Name |
|---|---|
| C1A4B | Stop Light Relay Circuit |
DESCRIPTION
The skid control ECU (brake actuator assembly) sends a stop light operation request signal to the stop light control ECU assembly. If the skid control ECU (brake actuator assembly) detects a malfunction in the stop light control ECU assembly circuit, the driving support ECU assembly stores DTC C1A4B.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| C1A4B | Stop Light Relay Circuit | Diagnosis condition:
Malfunction condition: Either of the following conditions is met:
|
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
Inspect the fuses for circuits related to this system before performing the following procedure.
When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.
Before replacing the certification ECU (smart key ECU assembly), refer to Service Bulletin.
PROCEDURE
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) CONNECTOR)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Connect the skid control ECU (brake actuator assembly) connector.
| Result | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| B |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - ECM) Click here |
| C |
|
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY) Click here |
| D |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY LH) Click here |
| E |
|
CHECK HARNESS AND CONNECTOR (+B/GND TERMINAL) Click here |
| A |
|
PERFORM ACTIVE TEST USING GTS (STOP LIGHT RELAY)
Turn the engine switch off.
Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.
Perform "Active Test" according to the display on the GTS.
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| Stop Light Relay | Stop light control ECU assembly | ON or OFF | Stop lights come on |
| Tester Display |
|---|
| Stop Light Relay |
| OK |
|---|
| Stop light turns ON/OFF in response to the GTS operation |
| Result | |||
|---|---|---|---|
|
| NG |
|
INSPECT SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) Click here |
| OK |
|
CHECK FOR DTC
Clear the DTCs.
Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.
Perform "Active Test" according to the display on the GTS.
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| Stop Light Relay | Stop light control ECU assembly | ON or OFF | Stop lights come on |
| Tester Display |
|---|
| Stop Light Relay |
Check for DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
USE SIMULATION METHOD TO CHECK Click here |
| B |
|
REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) Click here |
INSPECT SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)
Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.
Perform "Active Test" according to the display on the GTS.
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| Stop Light Relay | Stop light control ECU assembly | ON or OFF | Stop lights come on |
| Tester Display |
|---|
| Stop Light Relay |
| *a | Component with harness connected (Stop Light Switch Assembly) |
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY for LHD: Click here |
| NG |
|
REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) Click here |
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - ECM)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the A35 ECM connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the A35 ECM connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE ECM Click here |
| NG |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - SHIFT LOCK CONTROL UNIT ASSEMBLY)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the A35 ECM connector.
Disconnect the I22 shift lock control unit assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the I22 shift lock control unit assembly connector.
Connect the A35 ECM connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE SHIFT LOCK CONTROL UNIT ASSEMBLY Click here |
| NG |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the A35 ECM connector.
Disconnect the I22 shift lock control unit assembly connector.
Disconnect the I51 certification ECU (smart key ECU assembly) connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the I51 certification ECU (smart key ECU assembly) connector.
Connect the I22 shift lock control unit assembly connector.
Connect the A35 ECM connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
| NG |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the A35 ECM connector.
Disconnect the I22 shift lock control unit assembly connector.
Disconnect the I51 certification ECU (smart key ECU assembly) connector.
Disconnect the A3 stop light control ECU assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the A3 stop light control ECU assembly connector.
Connect the I51 certification ECU (smart key ECU assembly) connector.
Connect the I22 shift lock control unit assembly connector.
Connect the A35 ECM connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY for LHD: Click here |
| NG |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the A35 ECM connector.
Disconnect the I22 shift lock control unit assembly connector.
Disconnect the I51 certification ECU (smart key ECU assembly) connector.
Disconnect the A3 stop light control ECU assembly connector.
Disconnect the A1 stop light switch assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
Connect the A1 stop light switch assembly connector.
Connect the A3 stop light control ECU assembly connector.
Connect the I51 certification ECU (smart key ECU assembly) connector.
Connect the I22 shift lock control unit assembly connector.
Connect the A35 ECM connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY)
Turn the engine switch off.
Disconnect the A36 skid control ECU (brake actuator assembly) connector.
Disconnect the A1 stop light switch assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the A1 stop light switch assembly connector.
Connect the A36 skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE STOP LIGHT SWITCH ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
Turn the engine switch off.
Disconnect the A36 skid control ECU (brake actuator assembly) connector.
Disconnect the A3 stop light control ECU assemblyconnector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Connect the A3 stop light control ECU assemblyconnector.
Connect the A36 skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY for LHD: Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY LH)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the Q16 rear combination light assembly LH connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the Q16 rear combination light assembly LH connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE REAR COMBINATION LIGHT ASSEMBLY LH Click here |
| NG |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY RH)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the Q16 rear combination light assembly LH connector.
Disconnect the P13 rear combination light assembly RH connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the P13 rear combination light assembly RH connector.
Connect the Q16 rear combination light assembly LH connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE REAR COMBINATION LIGHT ASSEMBLY RH Click here |
| NG |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR LIGHT ASSEMBLY LH)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the Q16 rear combination light assembly LH connector.
Disconnect the P13 rear combination light assembly RH connector.
Disconnect the Y11 rear light assembly LH connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the Y11 rear light assembly LH connector.
Connect the P13 rear combination light assembly RH connector.
Connect the Q16 rear combination light assembly LH connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE REAR LIGHT ASSEMBLY LH Click here |
| NG |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR LIGHT ASSEMBLY RH)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the Q16 rear combination light assembly LH connector.
Disconnect the P13 rear combination light assembly RH connector.
Disconnect the Y11 rear light assembly LH connector.
Disconnect the Y10 rear light assembly RH connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the Y10 rear light assembly RH connector.
Connect the Y11 rear light assembly LH connector.
Connect the P13 rear combination light assembly RH connector.
Connect the Q16 rear combination light assembly LH connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE REAR LIGHT ASSEMBLY RH Click here |
| NG |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - CENTER STOP LIGHT ASSEMBLY)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the Q16 rear combination light assembly LH connector.
Disconnect the P13 rear combination light assembly RH connector.
Disconnect the Y11 rear light assembly LH connector.
Disconnect the Y10 rear light assembly RH connector.
Disconnect the e1 center stop light assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the e1 center stop light assembly connector.
Connect the Y10 rear light assembly RH connector.
Connect the Y11 rear light assembly LH connector.
Connect the P13 rear combination light assembly RH connector.
Connect the Q16 rear combination light assembly LH connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE CENTER STOP LIGHT ASSEMBLY Click here |
| NG |
|
INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
Turn the engine switch off.
| *a | Front view of harness connector (to Skid control ECU (brake actuator assembly)) |
Disconnect the skid control ECU (brake actuator assembly) connector.
Disconnect the Q16 rear combination light assembly LH connector.
Disconnect the P13 rear combination light assembly RH connector.
Disconnect the Y11 rear light assembly LH connector.
Disconnect the Y10 rear light assembly RH connector.
Disconnect the e1 center stop light assembly connector.
Disconnect the A3 stop light control ECU assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
Connect the A3 stop light control ECU assembly connector.
Connect the e1 center stop light assembly connector.
Connect the Y10 rear light assembly RH connector.
Connect the Y11 rear light assembly LH connector.
Connect the P13 rear combination light assembly RH connector.
Connect the Q16 rear combination light assembly LH connector.
Connect the skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (+B/GND TERMINAL)
| *a | Front view of harness connector (to Stop light control ECU assembly ) |
Turn the engine switch off.
Disconnect the A3 stop light control ECU assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Connect the A3 stop light control ECU assembly connector.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
Turn the engine switch off.
Disconnect the A36 skid control ECU (brake actuator assembly) connector.
Disconnect the A3 stop light control ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the A3 stop light control ECU assembly connector.
Connect the A36 skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY for LHD: Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
CHECK HARNESS AND CONNECTOR (+B/GND TERMINAL)
| *a | Front view of harness connector (to Stop light control ECU assembly ) |
Turn the engine switch off.
Disconnect the A3 stop light control ECU assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Connect the A3 stop light control ECU assembly connector.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
Turn the engine switch off.
Disconnect the A36 skid control ECU (brake actuator assembly) connector.
Disconnect the A3 stop light control ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Connect the A3 stop light control ECU assembly connector.
Connect the A36 skid control ECU (brake actuator assembly) connector.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |