OPERATION
- When the left and right front impact sensors detect a collision, the switches inside the sensors turns ON.
- SRS-ECU judges how severe a collision is by detecting signals from the front impact sensors and the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU outputs an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate.
DIAGNOSIS CODE SET CONDITIONS
These diagnosis codes are set if these is abnormal resistance between the input terminals of the front impact sensors.The most likely causes for these codes to be set are shown in the table below:
| Code No. |
Trouble causes |
|---|---|
| 11 |
|
| 12 |
|
| 13 |
|
PROBABLE CAUSES
- Malfunction of the front impact sensor
- Damaged wiring harnesses or connectors
- Malfunction of the SRS-ECU
DIAGNOSIS PROCEDURE
)
- Measure the resistance between terminals and check whether it is within the standard value.
Standard value: 820 ±
82 Ω
)
- Check for continuity between the terminal and bracket.
OK: No continuity.
Q: Does the resistance meet the value above, and is there no continuity?
YES:
Go to Step 2
.NO: Replace front impact sensor. Refer to
.)
- Measure the resistance between terminal 3 and terminal 4.
OK: 820 ±
82 Ω
Q: Does the resistance meet the value above?
YES:
Go to Step 4.NO: Go to Step 3
.STEP 3. Check the harness wires between SRS-ECU connector C-115 (terminal No.3 and 4) and front impact sensor (LH) connector A-17 (terminal No.1 and 2).
NOTE: After inspecting intermediate connector C-116, inspect the wiring harness. If the intermediate connector C-116 is damaged, repair or replace it. Then go to Step 6.
.Q: Are harness wires between SRS-ECU connector C-115 (terminal No.3 and 4) and front impact sensor (LH) connector A-17 (terminal No.1 and 2) in good condition?
YES:
Go to Step 6.NO: Repair the harness wires between SRS-ECU connector C-115 and front impact sensor (LH) connector A-17. Then go to Step 6
.)
- Resistance between terminal 1 and terminal 2.
OK: 820 ±
82 Ω
Q: Does the resistance meet the value above?
YES:
Erase the diagnosis code memory, and check the diagnosis code. If diagnosis code 11, 12 or 13 sets, replace the SRS-ECU. Refer to . Then go to Step 6
. NO: Go to Step 5
.STEP 5. Check the harness wires between SRS-ECU connector C-115 (terminal No.1 and 2) and front impact sensor (RH) connector A-28 (terminal No.1 and 2).
NOTE: After inspecting intermediate connector C-14 <2400>, C-29 <2000> inspect the wiring harness. If intermediate connector C-14 <2400>, C-29 <2000> is damaged, repair or replace it. Then go to Step 6.
.Q: Are harness wires between SRS-ECU connector C-115 (terminal No.1 and 2) and front impact sensor (RH) connector A-28 (terminal No.1 and 2) in good condition?
YES:
Go to Step 6.NO: Repair the harness wires between SRS-ECU connector C-115 and front impact sensor (RH) connector A-28. Then go to Step 6
.STEP 6. Check whether the diagnosis code is reset.
Q: Is any of diagnosis code 11, 12 or 13 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
.