Pinpoint Test A: No Communication With The Driver Seat Module (DSM): Overview
WARNING: This page is about a different car, the 2004 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
- A1 CHECK NGS TESTER COMMUNICATION TO THE DDM
- Using the results from the DATA LINK DIAGNOSTICS test, check for communication to the DDM.
- Does the scan tool communicate with the DDM?
- Yes : GO to A2.
- No : Go To PINPOINT TEST B .
- A2 CHECK CIRCUITS 29-AH80 (OG/WH) AND 30-AH80 (RD) FOR VOLTAGE WARNING: The restraint system diagnostic tool is for restraint system service only. Remove from vehicle prior to road use. Failure to remove could result in injury and possible violation of vehicle safety standards.NOTE: If a seat equipped with a seat mounted side air bag and/or a safety belt pretensioner (if equipped) system is being serviced, the air bag system must be depowered. Refer to AIR BAG RESTRAINT SYSTEMS .NOTE: The air bag warning lamp illuminates when the RCM fuse is removed and the ignition switch is ON. This is normal operation and does not indicate a supplemental restraint system (SRS) fault.NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
- Key in OFF position.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of AIR BAG RESTRAINT SYSTEMS .
- Disconnect: Driver Seat Side Air Bag Module C316.
- Connect: Restraint System Diagnostic Tool 418-133 or 501-097 to Driver Seat Side Air Bag Module C316.
- Connect: Battery Ground Cable.
- Disconnect: DSM C341b.
- Disconnect: DSM C341c.
- Measure the voltage between DSM C341c-10, circuit 29-AH80 (OG/WH), harness side and ground; and between DSM C341b-4, circuit 30-AH80 (RD), harness side and ground.
- Are the voltages greater than 10 volts?
WARNING: Be sure that nobody is in the vehicle and that there is nothing blocking or set in front of any air bag module when the battery ground cable is connected.- Yes : GO to A3.
- No : REPAIR the circuit in question. TEST the system for normal operation. DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from driver seat side air bag module C316. CONNECT driver seat side air bag module C316. REPOWER the supplemental restraint system (SRS). REFER to AIR BAG RESTRAINT SYSTEMS .
- A3 CHECK CIRCUIT 31-AH80 (BK) AND 91-AH80 (BN/WH) FOR AN OPEN
- Measure the resistance between the DSM C341 b-3, circuit 31-AH80 (BK), harness side and ground; and between DSM C341c-2, circuit 91-AH80 (BN/WH), harness side and ground.
- Are the resistances less than 5 ohms?
- Yes : REFER to MODULE COMMUNICATIONS NETWORK - LS .
- No : REPAIR the circuit. TEST the system for normal operation. DISCONNECT the battery ground cable. DISCONNECT the restraint system diagnostic tool from driver seat side air bag module C316. CONNECT driver seat side air bag module C316. REPOWER the supplemental restraint system (SRS). REFER to AIR BAG RESTRAINT SYSTEMS .