SDM Cannot Communicate through the Serial Data Circuit: Troubleshooting

WARNING: This page is about a different car, the 2006 Suzuki XL-7. However, it is still accessible from the selected car via links, so may be relevant.

TEST PROCEDURE - SDM CANNOT COMMUNICATE THROUGH SERIAL DATA CIRCUIT

Step	Action	YES	NO
1	Make sure that SUZUKI scan tool is free from malfunction for air bag system is used. Turn ignition switch OFF. Check for proper connection of SUZUKI scan tool to DLC. Is connection in good condition?	Go to Step 2.	Properly connect SUZUKI scan tool to DLC.
2	Check if communication is possible by trying communication with other control module (ECM, TCM (if equipped) or ABS control module (if equipped)). Is it possible to communicate with other control module?	Go to Step 3.	Repair open in common section of serial data circuit ("PPL/RED" wire circuit) used by all controllers or short to ground or power supply circuit which has occurred somewhere in serial data circuit ("PPL/RED" wire circuit).
3	With ignition switch OFF, disconnect SDM connector "G58". Check proper connection at "G58-12" ("PPL/RED" wire) terminal of SDM connector. If OK, then check resistance between "PPL/RED" wire terminal of DLC (1) and "G58-12" ("PPL/RED" wire) terminal of SDM connector. Special Tool (A): 09932-76010 Courtesy of SUZUKI OF AMERICA CORP. Is resistance 1 Ω or less?	Substitute a known-good SDM and recheck.	High resistance or open wire in "PPL/RED" circuit (in air bag harness).

NOTE: Upon completion of inspection and repair work, perform the following items.

Reconnect all air bag system components and ensure all components are properly mounted.
Repeat AIR BAG DIAGNOSTIC SYSTEM CHECK to confirm that the trouble has been corrected.