Test 3 – Check SRS unit

Test 3 – Check SRS unit

Connect Test Harness B:

1. Turn ignition OFF and disconnect SCS short connector.
2. Disconnect battery negative and then the positive terminal and wait 3 minutes.

4. SRS main harness
5. Passenger's airbag 3 – P connector
6. Short connector (RED)

3. Remove the glovebox and connect the short connector (RED) to the passenger's airbag 3 – P connector.
4. Disconnect SRS main harness 18 – P connector from SRS unit and connect Test Harness B between SRS unit and the 18 – P connector.

5. Connect jumper wires, as shown, to No. 13, 14, 15, and 16 terminals on rows A (SRS unit) and B (main harness) of Test Harness B. Ensure jumper wires are connected to the correct terminals.
6. Reconnect battery positive and negative terminals.
7. Connect voltmeter between terminals No. A1 (+) and No. A5 (-) of Test Harness B.
8. Turn ignition ON (II) and measure voltage, which should be 9.4 – 14 V.
9. Turn ignition OFF and measure resistance between terminals No. A7 and A5, which should be 0.75 – 1.0 ohm.
10. Connect voltmeter between terminals No. A7 and No. A5 of Test Harness B. There should be 0.5 V or less:

If voltage is as specified, go to Test 4.

If voltage is more than specified, SRS unit is faulty. Replace the unit.

Test 4 – Check for short circuit in SRS main harness

1. Turn ignition OFF.

1. Test Harness B – SMD 4088

2. Check for continuity between terminals No. B1 and No. B7 of Test Harness B.

Note: Do not connect the cable reel 6 – P connector.

If there is continuity, short circuit in SRS main harness. Replace harness.

If there is no continuity, problem corrected by reconnection. Ensure all terminals make good contact and recheck the system, see Fault Finding Intermittent Failures