SERVICE PRECAUTIONS

DANGER

In order to avoid injury to yourself or others from accidental deployment of the air bag during servicing, read and carefully follow all the precautions and procedures described in this manual.

CAUTION

Do not use any electrical test equipment on or near SRS components, except those specified on

CAUTION

Never Attempt to Repair the Following Components:

SRS air bag control unit (SRS-ECU)

Front impact sensor

Clock spring

Driver's and front passenger's air bag modules

Side air bag module

Side impact sensor

Seat belt with pre-tensioner

NOTE: If any of these components are diagnosed as faulty, they should only be replaced, in accordance with the INDIVIDUAL COMPONENTS SERVICE procedures in this manual, starting at page

CAUTION

Do not attempt to repair the wiring harness connectors of the SRS. If a defective wiring harness is found, repair or replace it by referring to the table below.

SRS-ECU terminal No.	Destination of harness	Remedy
1, 2	Instrument panel wiring harness → Front wiring harness (RH) → Front impact sensor (RH)	Correct or replace each wiring harness.
3, 4	Instrument panel wiring harness → Front wiring harness (LH) → Front impact sensor (LH)	Correct or replace each wiring harness.
7	Instrument panel wiring harness→ Earth	Correct or replace the instrument panel wiring harness.
8	Instrument panel wiring harness → SRS warning lamp	Correct or replace the instrument panel wiring harness.
9, 10	Instrument panel wiring harness → Air bag module (Front passenger's side)	Correct or replace the instrument panel wiring harness.
11, 12	Instrument panel wiring harness → Clock spring → Air bag module (Driver's side)	Correct or replace instrument panel wiring harness. Replace the clock spring.
13	Instrument panel wiring harness → Junction block (fuse No.3)	Correct or replace the instrument panel wiring harness.
16	Instrument panel wiring harness → Junction block (fuse No.2)	Correct or replace the instrument panel wiring harness.
20	Instrument panel wiring harness → Diagnosis connector	Correct or replace the instrument panel wiring harness.
21, 22	Floor wiring harness (RH) → Side air bag module (LH)	Correct or replace the floor wiring harness.
23, 24	Floor wiring harness (RH) → Side air bag module (RH)	Correct or replace the floor wiring harness.
27, 28	Floor wiring harness (LH) <2000>, floor wiring harness (RH) <2400> → Seat belt pre-tensioner (Front passenger's side)	Connect or replace the floor wiring harness.
29, 30	Floor wiring harness (RH) <2000>, floor wiring harness (LH) <2400> → Seat belt pre-tensioner (driver's side)	Connect or replace the floor wiring harness.
34, 36	Floor wiring harness (LH) → Side impact sensor (LH)	Connect or replace the floor wiring harness.
40, 42	Floor wiring harness (RH) → Side impact sensor (RH)	Connect or replace the floor wiring harness.

DANGER

After disconnecting the battery cable, wait 60 seconds or more before proceeding with the following work. In addition, insulate the negative battery terminal with a tape. The condenser inside the SRS-ECU is designed to retain enough voltage to deploy the air bag for a short time even after the battery has been disconnected, so serious injury may result from unintended air bag deployment if work is done on the SRS system immediately after the battery cables are disconnected.

CAUTION

The SRS components and seat belt with pre-tensioner should not be subjected to heat, so remove the SRS-ECU, driver’s and front passenger’s air bag modules, clock spring, side air bag modules, and seat belt pre-tensioner before drying or baking the vehicle after painting.

SRS-ECU, air bag modules, clock spring, impact sensors: 93°C or more

Seat belt with pre-tensioner: 90°C or more

CAUTION

Whenever you finish servicing the SRS, always erase the diagnosis code and check warning lamp operation to make sure that the system functions properly.

CAUTION

If checks are carried out by using the SRS-ECU harness connector, observe the following procedures: Insert the special tool (probe in the harness set) MB991222 into connector from harness side (rear side), and connect the tester to this probe. If any tool than special tool is used, damage to the harness and other components will result. Never insert the probe directly to the terminals from the front of the connector. The terminals are plated to increase their conductivity, so that if they are touched directly by the probe, the plating may break, which will cause drops in reliability.