How to Troubleshoot the SRS

DTC (Diagnostic Trouble Codes)

The self-diagnostic function of the SRS system allows it to locate the causes of system problems and then store this information in memory. For easier troubleshooting, this data can be retrieved via a data link circuit.

When you turn the ignition switch ON (II), the SRS indicator comes on. If it goes off after 6 seconds, the system is normal.
If there is an abnormality, the system locates and defines the problem, stores this information in memory, and turns the SRS indicator on. The data will remain in the memory even when the ignition switch is turned off or if the battery is disconnected.
When you connect the HDS to the 16P data link connector (DLC) to short the SCS terminal, and turn the ignition switch ON (II), the SRS indicator will indicate the primary diagnostic trouble code (DTC) by the number of blinks.
When you connect the HDS to the 16P data link connector (DLC), you can retrieve the DTC in the Honda Systems ‘‘SRS'' menu.
After reading and recording the DTC, proceed with the troubleshooting procedure for this code.

Precautions

Use only a digital multimeter to check the system. If it's not a Honda multimeter, 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 ON (II), or has been turned OFF for less than 3 minutes, be careful not to bump the SRS unit; the airbags could accidentally deploy and cause damage or injuries.
Before you remove the SRS harness, disconnect the driver's airbag connector, the front passenger's airbag connector, both side airbag connectors, and both seat belt tensioner connectors.
Make sure the battery is sufficiently charged. If the battery is dead or low, measuring values may not be correct.
Do not touch a tester probe to the terminals in the SRS unit or harness connectors, and do not connect the terminals with a jumper wire. Use only the backprobe set and the HDS. Backprobe spring-loaded lock type connectors correctly.

Reading the DTC

1.	Make sure the ignition switch is OFF.

2.	Connect the HDS to the DLC (A).

3.	Turn the ignition switch ON (II).

4.	Make sure the HDS communication with the vehicle and the SRS unit. If does not, troubleshoot the DLC circuit.

5.	Use the HDS to check for DTCs.

6.	Read the DTC.

7.	Turn the ignition switch OFF, and wait for 10 seconds.

8.	Disconnect the HDS from the DLC.

9.	Do the troubleshooting procedure for the DTC.

Erasing the DTC Memory

1.	Make sure the ignition switch is OFF.

2.	Connect the HDS to the DLC (A).

3.	Turn the ignition switch ON (II).

4.	Make sure the HDS communication with the vehicle and the SRS unit. If it does not, troubleshoot the DLC circuit.

5.	In the SRS MENU of the HDS, select SRS, then DTC to erase DTC(s).

6.	Turn the ignition switch OFF, and wait for 10 seconds.

7.	Disconnect the HDS from the DLC.

Troubleshooting Intermittent Failures

If there was a malfunction, but it does not recur, it will be stored in the memory as an intermittent failure, and the SRS indicator comes on.

After checking the DTC, troubleshoot as follows:

1.	Read the DTC (see ‘‘Reading the DTC'').

2.	Erase the DTC memory (see ‘‘Erasing the DTC Memory'').

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

4.	The SRS indicator will come on for about 6 seconds and then go off.

5.	Shake the related wire harness and connectors, and look for loose connections, poor pinfits, and poor grounds.

6.	Take a test-drive (quick acceleration, quick braking, and cornering), turn the steering wheel fully left and right, hold it there for 5 to 10 seconds. If the problem recurs, the SRS indicator will come on. NOTE: A faulty cable reel can cause intermittent connections related to the driver's airbag.

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