The diagnosis circuit constantly checks malfunction of the airbag system in the two stages shown below.
Ignition switch turned to ON position → 1. Primary check (for about six seconds) → 2. Constant check
1.Primary check
When the ignition switch is turned to the ON position from the LOCK position, the diagnosis circuit activates the airbag warning light for about six seconds to perform a primary check. If a malfunction is detected during the primary check, the airbag warning light does not go off and remains lit even after six seconds pass.
There used to be an E-type SRS airbag that performed the primary check when the ignition switch was in the ACC position.
In recent some models, if the airbag is deployed, the airbag warning light keeps on to leave a record even after the primary check.
In this case, the airbag warning light cannot be turned off.
2.Constant check
If no malfunction is detected during the primary check, the airbag warning light goes off after about six seconds to make the primer ready for ignition.
The diagnosis circuit begins a constant check at this time to constantly check component parts, power source system and wire harness for malfunction, open, short, etc. If a malfunction is detected during the constant check, the airbag warning light goes on or blinks to warn the driver.
3.Diagnostic code check
Diagnostic code(s) can be recovered as described. The code number is indicated by the blinking pattern of the SRS warning light.
(1)Using SST (service wire)
<1>Present trouble codes:
Turn the ignition switch to ON and wait for approximately 20 or 60 seconds depending on the models.
Using SST, connect between terminals TC and E1 of the DLC1 or DLC2, and TC and CG of the DLC3.
SST: 09843-18020 (DLC1, DLC2), 09843-18040 (DLC3)
<2>Past trouble codes:
Using SST, connect between terminals TC and E1 of the DLC1 or DLC2, and TC and CG of the DLC3.
Turn the ignition switch to ON and wait for approximately 20 or 60 seconds depending on the models.
(2)Using hand-held tester
Hook up the hand-held tester to DLC1, DLC2 or DLC3.
Read the diagnosis codes by following the prompts on the tester screen.
4.Diagnostic code clearance
(1)Description
Even after a malfunction has been repaired, the warning light will not go out when the ignition switch is in the ON position unless the stored codes are cleared. The procedure for clearing the stored codes varies according to the type of memory circuit.
For a RAM (Random Access Memory) memory circuit, the memory is erased when the power supply is cut off.
For an EEPROM* (Electrically Erasable Programmable ROM) memory circuit, the memory is not erased even if the power is cut off.
The method of the diagnostic code clearance of the EEPROM memory circuit is explained below in (2) and (3).
*EEPROM is also referred to as NV-RAM (non-volatile RAM).
(2)Code clearance by using hand-held tester
<1>Hook up the hand-held tester to DLC1, DLC2 or DLC3.
<2>Clear the diagnostic trouble codes by following the prompts on the tester screen.
(3)Code clearance by using SST (service wire)
For models using AB and TC terminals
<1>Connect service wires to terminals TC and AB respectively.
<2>Turn the ignition switch to ON and wait approximately six seconds.
<3>Starting with the TC terminal, alternately ground terminal TC and terminal AB twice each in cycles of 1.0