Diagnostic Trouble Codes
Caution: In order to avoid deploying the air bag when troubleshooting the SIR
system, use only the equipment specified in this manual and the instructions
given in this manual. Failure to use the specified equipment as instructed
could cause air bag deployment, personal injury to you or someone else,
or unnecessary SIR system repairs.
The SIR Diagnostic System Check must always be the starting
point of any SIR system diagnosis. The SIR Diagnostic System Check tests for
proper AIR BAG warning lamp operation and inspects for SIR Diagnostic Trouble
Codes (DTCs) using the scan tool. The following items describe the difference
between current and history DTCs:
| • | Current DTCs- Malfunctions that are presently being detected.
Random Access Memory (RAM) stores the current DTCs. Turning the ignition switch
to the OFF position erases current DTCs. The presence of a current DTC will
cause the inflatable restraint sensing and diagnostic module (SDM) to turn
the AIR BAG warning lamp ON. |
| • | History DTCs- All malfunctions detected since the last clearing
of history memory. Electrically Erasable Programmable Read Only Memory (EEPROM)
stores the history DTCs. A scan tool clear codes command erases history DTCs. |
Some DTCs are latched and cannot be cleared. Latched DTCs require the
replacement of the SDM after proper diagnosis.
Use of Special Tools
Ensure that you are familiar with the tools in this service category
listed under the heading Special Tools. You should know how to measure voltage
and resistance. Diagnosis requires proper use of the following tools:
| • | The J 38715-A
SIR
Driver/Passenger Load Tool |
| • | The J 35616
Connector
Test Adapter Kit |
