DTC 2D

DTC 2D Front impact sensor (RH) short-circuited to ground

Front Impact Sensor Circuit Part 1:

Front Impact Sensor Circuit Part 2:

CIRCUIT OPERATION
- When the left and right front impact sensors detect a collision, the switches inside the sensors turn 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 sends an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate.

DTC SET CONDITIONS
These DTCs are set if these are 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:

TROUBLESHOOTING HINTS
- Damaged harness wires and connectors
- Front impact sensor failed
- Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991911: M.U.T.-III Main Harness B

STEP 1. Check the front impact sensor.

Q: Is the check result satisfactory?

YES: Go to Step 2.

NO: Replace the front impact sensor.

STEP 2. Measure the resistance and voltage at SRS-ECU connector C-12.




1. Disconnect SRS-ECU connector C-12.

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




2. Take the measurements below at harness-side connector C-12.
- Resistance between terminals 1 and 2 as well as 3 and 4.
NG: 2 ohms or less (short circuit) or 2 megaohms or more (open circuit)







- Continuity between terminals 1, 2, 3, 4 and body ground

OK: No continuity




- Voltage between terminals 1, 2, 3, 4 and body ground

OK: 0V

Q: Is the check result satisfactory?

YES: Go to Step 4.

NO: Go to Step 3.
















STEP 3. Check the wiring harness between the right front impact sensor connector A-37 (terminals 1 and 2) and SRS-ECU connector C-12 (terminals 1 and 2) as well as between left front impact sensor connector A-33 (terminals 1 and 2) and SRS-ECU connector C-12 (terminals 3 and 4).

NOTE: Prior to the wiring harness Inspection, check intermediate connectors C-111 and C-134, and repair if necessary.

- Check the front impact sensor output line for open or short circuit.

Q: Is the check result satisfactory?

YES: Go to Step 4.

NO: Repair the wiring harness.

STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.




1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC 1A, 1B, 1C, 1D, 2A, 2B, 2C or 2D set?

YES: Replace the SRS-ECU.

NO: The procedure is complete (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to How to Use Troubleshooting/INSPECTION Service Points - How to Cope with Intermittent Malfunction).