Diagnosis code 43: SRS Warning Lamp Drive Circuit System Fault 1 (Lamp does not Illuminate).

OPERATION

Power for the SRS warning lamp is supplied from the ignition switch (IG1).

The SRS warning lamp illuminates when the ignition switch is turned to the "ON" position and goes out after approximately 7 seconds if there is not a malfunction in the SRS system.

DIAGNOSIS CODE SET CONDITIONS

This diagnosis code is set when an open circuit is detected for a continuous period of 5 seconds while the SRS-ECU is monitoring the SRS warning lamp and the lamp is OFF. (transistor OFF). However, if the vehicle condition returns to normal, diagnosis code 43 will be automatically erased, and the SRS warning lamp will go out.

PROBABLE CAUSES

Damaged wiring harnesses or connectors

Malfunction of the SRS-ECU

Malfunction of the combination meter

DIAGNOSIS PROCEDURE

STEP 1. Check the SRS warning lamp.

Disconnect the negative battery terminal.

Connect the negative battery terminal.

Disconnected the SRS-ECU connector C-115.

Turn the ignition switch to the "ON" position.

Q: Does the warning lamp illuminate?

YES: Erase the diagnosis code memory, and check the diagnosis code. If diagnosis code 43 sets, replace the SRS-ECU (Refer to

). Then go to Step 5

.
NO: Go to Step 2

STEP 2. Check the earth line at the SRS-ECU connector C-115.

Disconnect the negative battery terminal.

Connect the negative battery terminal.

Turn the ignition switch to the "ON" position.

CAUTION

Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.

Measure the continuity between C-115 harness side connector terminal 7 and earth.

OK: Less than 2 Ω

Q: Is the check result normal?

YES: Go to Step 3

.
NO: Go to Step 4

STEP 3. Check the harness for open circuit between ignition switch connector C-303 (terminal No.2) and combination meter C-04 (terminal No.42), and between combination meter C-05 (terminal No.11) and SRS-ECU connector C-115 (terminal No.8).

NOTE: After inspecting intermediate connectors C-05, C-04, C-205 and C-203 inspect the wiring harness. If intermediate connectors C-05, C-04, C-205 and C-203 are damaged, repair or replace them. Then go to Step 5

Q: Are the harness wires between SRS-ECU connector C-115 (terminal No.8) and the ignition switch connector C-303 (terminal No.2) in good condition?

YES: Replace the combination meter (Refer to GROUP 54A - Combination Meters Assembly and Vehicle Speed Sensor

). Then go to Step 5

.
NO: Repair the harness wires between SRS-ECU connector C-115 and the ignition switch connector C-303. Then go to Step 5

STEP 4. Check the harness for open circuit between SRS-ECU connector C-115 (terminal No.7) and earth.

Q: Is the harness wire between SRS-ECU connector C-115 (terminal No.7) and earth in good condition?

YES: Go to Step 5

.
NO: Repair the harness wires between SRS-ECU connector C-115 and earth. Then go to Step 5

STEP 5. Check whether the diagnosis code is reset.

Q: Is diagnosis code 43 set?

YES: Return to Step 1

.
NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected). Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points


Diagnosis code 43: SRS Warning Lamp Drive Circuit System Fault 1 (Lamp does not Illuminate).

OPERATION Power for the SRS warning lamp is supplied from the ignition switch (IG1). The SRS warning lamp illuminates when the ignition switch is turned to the "ON" position and goes out after approximately 7 seconds if there is not a malfunction in the SRS system.
DIAGNOSIS CODE SET CONDITIONS This diagnosis code is set when an open circuit is detected for a continuous period of 5 seconds while the SRS-ECU is monitoring the SRS warning lamp and the lamp is OFF. (transistor OFF). However, if the vehicle condition returns to normal, diagnosis code 43 will be automatically erased, and the SRS warning lamp will go out.
PROBABLE CAUSES Damaged wiring harnesses or connectors Malfunction of the SRS-ECU Malfunction of the combination meter
	DIAGNOSIS PROCEDURE

	STEP 1. Check the SRS warning lamp. Disconnect the negative battery terminal. Connect the negative battery terminal. Disconnected the SRS-ECU connector C-115. Turn the ignition switch to the "ON" position. Q: Does the warning lamp illuminate? YES: Erase the diagnosis code memory, and check the diagnosis code. If diagnosis code 43 sets, replace the SRS-ECU (Refer to ). Then go to Step 5 . NO: Go to Step 2.
	STEP 2. Check the earth line at the SRS-ECU connector C-115. Disconnect the negative battery terminal. Connect the negative battery terminal. Turn the ignition switch to the "ON" position.
	CAUTION Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened. Measure the continuity between C-115 harness side connector terminal 7 and earth. OK: Less than 2 Ω Q: Is the check result normal? YES: Go to Step 3. NO: Go to Step 4.
	STEP 3. Check the harness for open circuit between ignition switch connector C-303 (terminal No.2) and combination meter C-04 (terminal No.42), and between combination meter C-05 (terminal No.11) and SRS-ECU connector C-115 (terminal No.8). NOTE: After inspecting intermediate connectors C-05, C-04, C-205 and C-203 inspect the wiring harness. If intermediate connectors C-05, C-04, C-205 and C-203 are damaged, repair or replace them. Then go to Step 5 . Q: Are the harness wires between SRS-ECU connector C-115 (terminal No.8) and the ignition switch connector C-303 (terminal No.2) in good condition? YES: Replace the combination meter (Refer to GROUP 54A - Combination Meters Assembly and Vehicle Speed Sensor ). Then go to Step 5. NO: Repair the harness wires between SRS-ECU connector C-115 and the ignition switch connector C-303. Then go to Step 5.
	STEP 4. Check the harness for open circuit between SRS-ECU connector C-115 (terminal No.7) and earth. Q: Is the harness wire between SRS-ECU connector C-115 (terminal No.7) and earth in good condition? YES: Go to Step 5 . NO: Repair the harness wires between SRS-ECU connector C-115 and earth. Then go to Step 5.
	STEP 5. Check whether the diagnosis code is reset. Q: Is diagnosis code 43 set? YES: Return to Step 1 . NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected). Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points .