Code No.B1611: Seat belt pre-tensioner (passenger’s side) (squib) system (short-circuited to the earth)




OPERATION


The 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 seat belt pre-tensioner will deploy.

DIAGNOSIS CODE SET CONDITIONS


This diagnosis code is set if seat belt pre-tensioner (passenger’s side) wire(s) are short-circuited to the earth.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Check the diagnosis code by connecting a dummy resistor. (M.U.T.-III diagnosis code)
(1)Disconnect the negative battery terminal.


(2)Disconnect seat belt pre-tensioner (passenger’s side) connector D-23 <LHD>, D-15 <RHD>. Use a flat-tipped screwdriver to pull out the locking button at the harness side connector, and then disconnect the connector.

(3)Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991884).
(4)Connect special tool (MB991884) to the D-23 <LHD>, D-15 <RHD> harness side connector.
(5)Connect the negative battery terminal.
(6)Erase diagnosis code memory, and then check the diagnosis code.

Q. Is diagnosis code B1611 set?

Go to Step 2.

Replace the seat belt with pre-tensioner (passenger’s side) (Refer to ).

STEP 2. Resistance measurement at the SRS-ECU connector C-153


(1)Disconnect the negative battery terminal.

(2)Disconnect SRS-ECU connector C-153.


(3)
danger To prevents the seat belt pre-tensioner from deploying unintentionally, disconnect the seat belt pre-tensioner (passenger’s side) connector D-23 <LHD>, D-15 <RHD> to short the squib circuit.
Disconnect seat belt pre-tensioner (passenger’s side) connector D-23 <LHD>, D-15 <RHD>. Use a flat-tipped screwdriver to pull out the locking button at the harness side connector, and then disconnect the connector.

(4)
caution Insert an insulator such as a cable tie to a depth of 7 mm or more, otherwise the short spring will not be released.
Insert a cable tie [3 mm wide, 0.5 mm thick] between terminals 5, 6 and the short spring to release the short spring.

(5)
caution Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
Resistance measurement between C-153 harness side connector terminals 5, 6 and body earth.
OK: Open circuit

Q. Is the check result normal?

Go to Step 3 .

Repair the harness wires between SRS-ECU connector C-153 (terminal No.5 and 6) and the seat belt pre-tensioner (passenger’s side) connector D-23 <LHD>, D-15 <RHD> (terminal No.1 and 2).

STEP 3. Check whether the diagnosis code is reset.

Q. Is diagnosis code B1611 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).