Code No.B1595 Front impact sensor RH system (short circuit in the sensor)
Code No.B1596 Front impact sensor RH system (open circuit in the sensor)
Code No.B1597 Front impact sensor RH (short circuited in the earth)
Code No.B1598 Front impact sensor RH (short circuited in the power supply)
Code No.B1599 Front impact sensor LH system (short circuit in the sensor)
Code No.B1600 Front impact sensor LH (open circuit in the sensor)
Code No.B1601 Front impact sensor LH (short circuited in the earth)
Code No.B1602 Front impact sensor LH (short circuited in the power supply)




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 analogue 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.

DIAGNOSIS CODE SET CONDITIONS




Code No.
 Trouble causes
B1595
 Right front impact sensor or its wiring shorted
B1596
 Right front impact sensor or wiring open circuit
B1597
 Short to body earth in the right front impact sensor harness
B1598
 Short to the power supply in the right front impact sensor harness
B1599
 Left front impact sensor or its wiring shorted
B1600
 Left front impact sensor or wiring open circuit
B1601
 Short to body earth in the left front impact sensor harness
B1602
 Short to the power supply in the left front impact sensor harness
PROBABLE CAUSE
  • Damaged harness wires and connectors
  • Front impact sensor failed
  • Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the front impact sensor.
Refer to .

Q. Is the check result normal?
Go to Step 2.
Replace the front impact sensor (Refer to ).

STEP 2. Resistance measurement at the SRS-ECU connector C-131.
(1)Disconnect the negative battery terminal.

(2)Disconnect SRS-ECU connector C-131.


(3)
caution Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
Take the measurements below at harness side connector C-131.

  • Resistance between terminals 1 and 2 as well as 3 and 4.
NG: open circuit

(4)
  • Continuity between terminals 1, 2, 3, 4 and body earth
OK: Open circuit

Q. Is the check result normal?

Go to Step 3.

Repair the harness wire between the front impact sensor (RH) connector A-124 (terminals 1 and 2) and SRS-ECU connector C-131 (terminals 1 and 2) as well as between front impact sensor (LH) connector A-30 (terminals 1 and 2) and SRS-ECU connector C-131 (terminals 3 and 4).

STEP 3. Voltage measurement at the SRS-ECU connector C-131.
(1)Disconnect the negative battery terminal.

(2)Disconnect SRS-ECU connector C-131.
(3)Connect the negative battery terminal.
(4)Turn the ignition switch to the "ON" position.

(5)
caution Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
Take the measurements below at harness-side connector C-131.
(6)
  • Voltage between terminals 1, 2, 3, 4 and body earth
OK: 0V

Q. Is the check result normal?

Go to Step 4.

Repair the harness wire between the front impact sensor (RH) connector A-124 (terminals 1 and 2) and SRS-ECU connector C-131 (terminals 1 and 2) as well as between front impact sensor (LH) connector A-30 (terminals 1 and 2) and SRS-ECU connector C-131 (terminals 3 and 4).

STEP 4. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set.

Q. Is diagnosis code B1595, B1596, B1597, B1598, B1599, B1600, B1601 or B1602 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).