Supplemental Restraint System - Diagnostics: Pre-Check

DIAGNOSIS SYSTEM

Check the DLC3.

The vehicle's ECM conforms to ISO 9141 - 2 for communication protocol. The terminals arrangement of the DLC3 complies with SAE J1962 and meets the ISO 9141 - 2 format.

Fig 1: Checking DLC3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TERMINAL VOLTAGE

Terminal No.	Connection/Voltage or Resistance	Condition
4	Chassis Ground - Body Ground/1 Ω or less	Always
7	Bus + Line/Pulse generation	During Transmission
16	Battery Positive - Body Ground/11 - 14 V	Always

NOTE: If the display shows UNABLE TO CONNECT TO VEHICLE when connecting the cable of the hand-held tester to the DLC3, turning the ignition switch to the ON position and operating the TOYOTA hand-held tester, there is a problem on the vehicle side or tool side.

If communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle.
If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tool itself. Consult the Service Department listed in the tool's instruction manual.

FUNCTION OF SRS WARNING LIGHT
1. Primary check.
  Turn the ignition switch to the LOCK position. Wait for at least 2 seconds, then turn the ignition switch to the ON position. The SRS warning light comes on for approximately 6 seconds and the diagnosis of the SRS airbag system (including the seat belt pretensioner) is performed.
  
  NOTE: If trouble is detected during the primary check, the SRS warning light remains on or blinks even after the primary check period (approximately 6 seconds) has elapsed.
2. Constant check.
  After the primary check, the airbag sensor assembly activates the SRS airbag system and constantly monitors it for trouble.
  
  NOTE: If trouble is detected during the constant check, the airbag sensor assembly functions as follows.
  - The SRS warning light comes on or blinks.
  - The SRS warning light comes on, and then goes off. This blinking pattern indicates the source voltage drop.
  The SRS warning light goes off 10 seconds after the source voltage returns to normal.
3. Review.
  1. When the airbag system is normal;
    The SRS warning light comes on only for the primary check period (for approximately 6 seconds after the ignition switch is turned to the ON position).
  2. When the airbag system has trouble;
    - The SRS warning light remains on or blinks even after the primary check period has elapsed.
    - The SRS warning light goes off after the primary check, but comes on or blinks again during the constant check.
    - The SRS warning light does not come on when turning the ignition switch from the LOCK to ON position.
NOTE: The airbag sensor assembly keeps the SRS warning light on if the airbag has been deployed.
CHECK SRS WARNING LIGHT
1. Turn the ignition switch to the ON position, and check that the SRS warning light comes on for approximately 6 seconds (primary check).
2. Check that the SRS warning light goes off approximately 6 seconds after the ignition switch is turned to the ON position (constant check).
Fig 2: Identifying SRS Warning Light
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NOTE: When any of the following symptoms occurs, refer to PROBLEM SYMPTOMS TABLE .
- When the SRS warning light comes on occasionally, even after the primary check period has elapsed.
- When the SRS warning light comes on, even when neither the DTC nor normal system code does not output, trouble in the power source or combination meter is suspected.
- When the ignition switch is turned from the LOCK to ON position, the SRS warning light does not come on.
DTC CHECK (USING SST CHECK WIRE)
1. Check the DTCs (Present trouble code).
  1. Turn the ignition switch to the ON position, and wait for approximately 60 seconds.
  2. Using SST, connect the terminals TC and CG of the DLC3.
  SST 09843-18040
  
  NOTE: Pay attention to the terminal connecting position to avoid causing a malfunction.
  
  Fig 3: Connecting Terminals TC And CG Of DLC3 Using SST
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the DTCs (Past trouble code).
  1. Using SST, connect the terminals TC and CG of the DLC3.
    SST 09843-18040
    
    NOTE: Pay attention to the terminal connecting position to avoid causing a malfunction.
  2. Turn the ignition switch to the ON position, and wait for approximately 60 seconds.
3. Read the DTCs.
  Read the blinking patterns of the DTCs. As examples, the blinking patterns for normal system code and trouble codes 11 and 31 are shown in the illustration to the left.
  - Normal system code indication (w/o past trouble code)
    The light blinks twice per second.
  - Normal system code indication (w/ past trouble code)
    When the past trouble code is stored in the airbag sensor assembly, the light blinks only once a second.
  - Trouble code indication
  The first blinking indicates the first DTC. The second blinking occurs after a 1.5-second pause.
  
  If there are 2 or more codes, there will be a 2.5-second pause between each code. After all codes are shown, there will be a 4.0-second pause, and they all will be repeated.
  NOTE:
  - If 2 or more malfunctions are found, the indication begins with the smaller numbered code.
  - If the DTCs are indicated without connecting of the terminals, proceed to the "TC Terminal Circuit" on page ##DI-620.
  Fig 4: Identifying DTC Blinking Pattern
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Clear the DTCs.
  1. When the ignition switch is turned off, the DTCs are cleared.
    NOTE: Depending on the DTC, the code may not be cleared by turning off the ignition switch. In this case, proceed to the next procedure.
  2. Using SST, connect the TC and CG of the DLC3, and then turn the ignition switch to the ON position.
    SST 09843-18040
  3. Disconnect the TC of the DLC3 within 3 to 10 seconds after the DTCs are output, and check if the SRS warning light comes on after 3 seconds.
  4. Within 2 to 4 seconds after the SRS warning light comes on, connect the TC and CG of the DLC3.
  5. The SRS warning light should go off within 2 to 4 seconds after connecting the TC and CG of the DLC3.
    Then, disconnect the TC terminal within 2 to 4 seconds after the SRS warning light goes off.
  6. The SRS warning light comes on again within 2 to 4 seconds after disconnecting the TC terminal.
    Then, reconnect terminals TC and CG within 2 to 4 seconds after the SRS warning light comes on, and connect the TC and CG of the DLC3.
  7. Check if the SRS warning light goes off within 2 to 4 seconds after connecting the TC and CG of the DLC3, and the normal system code is output within 1 second after the SRS warning light goes off.
  If DTCs are not cleared, repeat the procedure (d) until the codes are cleared.
  
  Fig 5: Identifying Warning Light Blinking Pattern
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. DTC CHECK (USING TOYOTA HAND-HELD TESTER)
1. Check the DTCs.
  1. Connect the TOYOTA hand-held tester to the DLC3.
  2. Turn the ignition switch to the ON position.
  3. Read the DTCs by following the prompts on the tester screen.
  NOTE: Refer to the TOYOTA hand-held tester operator's manual for further details.
2. Clear the DTCs.
  1. Connect the TOYOTA hand-held tester to the DLC3.
  2. Turn the ignition switch to the ON position.
  3. Clear the DTCs by following the prompts on the tester screen.
  NOTE: Refer to the TOYOTA hand-held tester operator's manual for further details.
6. PREPARE FOR INSPECTION (FOR UNEXPECTED AIRBAG DEPLOYMENT)
CAUTION: When troubleshooting for each of the following squibs (D squib, P squib, Side squib LH and RH and P/T squib LH and RH), be sure to perform the following procedure at the indicated steps in each troubleshooting to avoid unexpected airbag deployment.
1. Turn the ignition switch to the LOCK position.
2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
3. Disconnect the connectors from the airbag sensor assembly.
4. Remove the steering wheel pad (See REMOVAL ).
5. Disconnect the connector from the front passenger airbag assembly (See REMOVAL ).
6. w/ Side airbag:
  Disconnect the connectors from the side airbag assembly RH and LH (See REMOVAL ).
7. Disconnect the connectors from the seat belt pretensioner RH and LH (See SEAT BELT PRETENSIONER (SEDAN) and SEAT BELT PRETENSIONER (HATCHBACK) ).
8. (h) Disconnect the connectors from the front airbag sensor RH and LH (See REMOVAL ).
9. (i) w/ Side airbag:
  Disconnect the connectors from the side airbag sensor assembly RH and LH (See REMOVAL - 2 DOOR and REMOVAL - 4 DOOR ).
10. (j) 2-Door w/ Side airbag:
Disconnect the connectors from the door side airbag sensor RH and LH (See REMOVAL ).
7. RELEASE METHOD OF ACTIVATION PREVENTION MECHANISM

The activation prevention mechanism is built into the connector for the squib circuit of the SRS. As explained later, during troubleshooting, insert a piece of paper with the same thickness as the male terminal, between the terminal and the short spring to release it (Refer to illustrations on the next 2 pages).

CAUTION: Never release the activation prevention mechanism of the squib connector.

NOTE:

Do not release the activation prevention mechanism unless specially directed by the troubleshooting procedure.
To prevent the terminal and the short spring from being damaged, always use a piece of paper with the same thickness as the male terminal.

Fig 6: Identifying Airbag Sensor Assembly Connections (1 Of 2)

Fig 7: Identifying Airbag Sensor Assembly Connections (2 Of 2)