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 tests for SIR Diagnostic Trouble
Codes (DTC) using the scan tool. The following list describes the difference
between current and history DTCs:
| • | Current DTCs are 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
ON the AIR BAG warning lamp. |
| • | History DTCs are all malfunctions detected since last clearing
of history memory. Electrically Erasable Programmable Read Only Memory (EEPROM)
stores the history DTCs. A scan tool clear codes command will erase history
DTCs. |
Some DTCs are latched and can not be cleared. Latched DTCs will require
replacement of the SDM after proper diagnostics.
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 |
