Initial Inspection and Diagnostic Overview

Control System DTCs

How to Troubleshoot the SRS

How to Troubleshoot Circuits at the SRS Unit Connectors

Special Tools Required

Pin Probe Male 07ZAJ-RDJA110

1. When diagnosing or troubleshooting at an SRS unit connector (A), use the terminal test port below the terminal you need to check. Gently insert the pin probes of the tester or jumper wire at the terminal test port from the terminal side.

NOTE:
* Do not insert the pin probes of the tester or a jumper wire at the terminal or the SRS short canceller terminal port.
* To prevent damage to the connector terminals, do not insert the test equipment probes, paper clips, or other substitutes as they can damage the terminals. Damaged terminals cause a poor connection and an incorrect measurement.

2. Connect one side of the patch cord terminals (A) to a commercially available digital multimeter (B), and connect the other side of the terminals (C) to the pin probe male.

NOTE:
* Do not insert the pin probes of the tester or a jumper wire into the terminal.
* To prevent damage to the connector terminals, do not insert the test equipment probes, paper clips, or other substitutes as they can damage the terminals. Damaged terminals can cause a poor connection and an incorrect measurement.

2. Connect one side of the patch cord terminals (A) to a commercially available digital multimeter (B), and connect the other side of the terminals (C) to the pin probe male.

3. Gently contact the pin probe male at the terminal test port from the terminal side. Do not force the tips into the terminals.

NOTE:
* For accurate results, always use the pin probe male.
* To prevent damage to the connector terminals, do not insert test equipment probes, paper clips, or other substitutes. Damaged terminals cause a poor connection and an incorrect measurement.
* Do not puncture the insulation on a wire. Punctures can cause poor or intermittent electrical connections.

How to Troubleshoot Circuits at the Connectors Except for SRS Unit Connectors and Waterproof SRS Connectors

Special Tools Required

Back Probe Adapter, 17 mm 07TAZ-001020A

When using electrical test equipment, insert the back probe adapter, 17 mm of the tester into the wire side of the connector (except SRS unit connector and waterproof connector).

NOTE:
* Make sure the battery is fully charged when doing electrical test. If the battery is not fully charged, the results of the tests may not be accurate.
* Do not insert the probe of the tester into the terminal side of the connector, and do not tamper with the connector.
* To prevent damage to the connector, do not insert test equipment probes, paper clips, or other substitutes. Damaged terminals cause a poor connection and an incorrect measurement.
* Do not puncture the insulation on a wire. Punctures can cause poor or intermittent electrical connections.
* Do not insert the probe forcibly.
* Use specified service connectors in troubleshooting. Using improper tools could cause a diagnostic error due to poor metal-to-metal contact.

Opening the SRS Unit Shorting Connectors for Diagnosis

Special Tools Required

SRS Short Canceller 070AZ-SAA0100
NOTE:
* To prevent damage to the connector cavity, insert an SRS short canceller straight into the cavity from the terminal side.
* Before installing an SRS short canceller, wash it with electrical contact cleaner, then dry it with compressed air.
* Do not use an SRS short canceller if it is damaged.
* Make sure to remove an SRS short canceller before reconnecting the SRS unit connector.
* Some systems store data in memory that is lost when the battery is disconnected. Before disconnecting the battery, refer to Battery Terminal Disconnection and Reconnection Procedures.

When SRS unit connectors A (39P) and B (39P) are disconnected, short circuits are automatically created in the connector to prevent accidental deployment of an airbag or tensioner. The circuit may need to be opened sometimes when diagnosing the system. Insert an SRS short canceller in the specified cavities when necessary to keep the circuit open for diagnosis.

Terminal numbers are shown on the terminal side of the female terminals. Insert the SRS short canceller(s) into the cavities on the terminal side of the connector.

DTC (Diagnostic Trouble Codes)

The self-diagnostic function of the SRS unit allows it to locate the causes of system problems and store this information in memory. For easier troubleshooting, this data can be retrieved with the HDS via the data link circuit.
* When you turn the ignition switch to ON (II), the SRS indicator should come on. If it goes off after 6 seconds, the system is normal, and is not currently detecting any problems.
* If there is a problem, the system locates and defines the problem, stores this information in the memory, and turns on the SRS indicator. The data remains in the memory even if the ignition switch is turned to LOCK (0), or the battery is disconnected.
* The data is stored in memory as a diagnostic trouble code (DTC).
* DTCs are either latching or resetting depending on the malfunction. With resetting DTCs, the SRS indicator goes off the next time the ignition switch is turned to ON (II), and the system is normal, but the DTC is still stored. With latching DTCs, the SRS indicator does not turn off until the malfunction is repaired and the DTC is cleared.
* When you connect the HDS to the data link connector (DLC), you can retrieve a more detailed DTC in the HDS "SRS" menu.

NOTE: Only read DTCs from the SRS menu, not from SWS menus unless instructed to check SWS DTCs. SWS (ODS unit) DTCs are subcodes of SRS DTCs. Only troubleshoot the corresponding SRS DTCs. These SWS DTCs are cleared when you turn the ignition switch to LOCK (0).
* After reading and recording the DTC, go to the troubleshooting procedure for that code.

Precautions

* Make sure the battery is fully charged. If the battery is dead or low, electrical measurements values may not be correct.
* Use only a digital multimeter to check the system. Make sure its output is 10 mA (0.01 A) or less when switched to the smallest value in the ohmmeter range. A tester with a higher output could damage the airbag circuit or cause accidental airbag deployment and possible injury.
* Whenever the ignition switch is in ON (II), or has been turned to LOCK (0) for less than 3 minutes, be careful not to bump the SRS unit; the airbags could accidentally deploy and cause damage or injuries.
* Before removing the dashboard wire harness or floor wire harness, disconnect the driver's airbag inflator connector, the front passenger's airbag inflator connector, both side airbag inflator connectors, both side curtain airbag inflator connectors, and both front seat belt tensioner connectors.

How to Read DTCs

NOTE: Make sure the battery is fully charged before you begin.

1. Turn the ignition switch to LOCK (0), then wait for 10 seconds.

2. Connect the HDS to the data link connector (DLC) (A).

3. Turn the ignition switch to ON (II).

4. Make sure the HDS communicates with the vehicle and the SRS unit. If it does not communicate, go to the DLC circuit troubleshooting Testing and Inspection.

5. Use the HDS to check for SRS DTCs.

6. Read and record the DTC.

NOTE:
* Only read DTCs from the SRS menu, not from SWS menus unless instructed to check SWS DTCs. SWS (ODS unit) DTCs are subcodes of SRS DTCs. Only troubleshoot the corresponding SRS DTCs. These SWS DTCs are cleared when you turn the ignition switch to LOCK (0).
* Do not clear the DTCs until instructed by the troubleshooting procedure.

7. Turn the ignition switch to LOCK (0), then wait for 10 seconds.

8. Disconnect the HDS from the DLC.

9. Do the troubleshooting procedure for the DTC.

How to Clear DTCs

NOTE: Make sure the battery is fully charged before you begin.

1. Turn the ignition switch to LOCK (0), then wait for 10 seconds.

2. Connect the HDS to the data link connector (DLC) (A).

3. Turn the ignition switch to ON (II).

4. Make sure the HDS communicates with the vehicle and the SRS unit. If it does not communicate, go to the DLC circuit troubleshooting Testing and Inspection.

5. In the SRS MENU of the HDS, select SRS, then DTC to clear DTCs.

6. Turn the ignition switch to LOCK (0), then wait for 10 seconds.

7. Disconnect the HDS from the DLC.

Troubleshooting Intermittent Failures

If there was a malfunction that sets a DTC, but it does not recur, a DTC will be stored in the memory, and the SRS indicator may come on depending on the malfunction detected.

NOTE:
* Check the condition of the battery Component Tests and General Diagnostics. Low battery voltage may cause some intermittent failures.
* A faulty or damaged cable reel can cause intermittent problems related to the driver's airbag inflator DTCs.

After checking the DTC, troubleshoot as follows:

1. Check for DTCs with the HDS.

2. Clear the DTCs with the HDS.

3. Set the parking brake, then start the engine, and let it idle.

4. The SRS indicator comes on for about 6 seconds and then goes off.

5. Shake the related wire harnesses and the connectors, and look for loose connections, poor pin fits, and poor grounds.

6. Take a test-drive (quick acceleration, quick braking, and cornering), turn the steering wheel fully left and right, and hold it there for 5 to 10 seconds. If the problem recurs, the SRS indicator will come on.

7. If you cannot duplicate the concern, ask the customer about the conditions when it occurred, or ask the customer to demonstrate the concern.

8. If you cannot duplicate the intermittent failure, the system is OK at this time.