DTC 71
DTC 71 Internal SDM Fault
Circuit Description:
Diagnostic Trouble Code (DTC) 71 is an indication of a potential internal Sensing and Diagnostic Module (SDM) malfunction and will set if any of the following conditions are detected:
1. Deployment or microprocessor energy reserve failure.
2 Electronically Erasable Programmable Read Only Memory failure. (EEPROM).
3. Random Only Memory failure. (ROM).
4 Random Access Memory failure. (RAM).
5. Calibration check sum failure.
6. Deployment switch faults.
7. Accelerometer fault.
8. Arming sensor fault.
9. Diagnostic current faults.
10. DTC 19
11. DTC 25
12. DTC 51
13. DTC 53
DTC Will Set When:
Any of the above indicated malfunctions are detected by the SDM. The malfunctions described above are tested mainly during "Continuous Monitoring" and some ones run each ignition cycle.
Action Taken:
SDM turns "ON" the "AIR BAG" warning lamp and sets a diagnostic trouble code.
DTC Will Clear When:
A scan tool "Clear Codes" commanded is received by the SDM. Some of the indicated malfunctions will only allow the "AIR BAG" warning lamp to go out.
But when DTC 19, 25, 51, 53 are also set, SDM is Replaced.
DTC 71 (Steps 1 And 2):
DTC 71 Internal SDM Fault
WARNING: DURING SERVICE PROCEDURES. BE VERY CAREFUL WHEN HANDLING A SENSING AND DIAGNOSTIC MODULE (SDM). NEVER STRIKE OR JAR THE SDM. NEVER POWER UP THE SRS WHEN THE SDM IS NOT RIGIDLY ATTACHED TO THE VEHICLE. ALL SDM AND MOUNTING BRACKET FASTENERS MUST BE CAREFULLY TORQUED AND THE ARROW MUST BE POINTING TOWARD THE FRONT OF THE VEHICLE TO ENSURE PROPER OPERATION OF THE SRS. THE SDM COULD BE ACTIVATED WHEN POWERED WHILE NOT RIGIDLY ATTACHED TO THE VEHICLE WHICH COULD CAUSE DEPLOYMENT AND RESULT IN PERSONAL INJURY.
CAUTION: When Diagnostic Trouble Code (DTC) 19 or 25 or 51 or 53 has been set it is necessary to Replace the SDM. Setting DTC 19 and 25 or 51 or 53 will also cause DTC 71 to set. When a scan tool "CLEAR CODES" command is issued and the malfunction is no longer present, DTC 51 or 53 and DTC 71 will remain current. Ensure that the short to voltage condition DTC 19, 25 is repaired prior to installing a Replacement SDM to avoid damaging the SDM.