DTC 22 - Driver Initiator Circuit Resistance Low

Every time ignition switch is turned to ON position, SDM performs a series of self tests to check for internal malfunctions. If no internal faults are detected, SDM measures voltages in ignition 1, 36 VLR (back-up power supply), and deployment loop circuits. If all of these circuit voltages are within pre-defined parameters, SDM will measure resistance of driver-side inflator module. This is accomplished by allowing a small amount of current to flow from A1 terminal, through driver-side inflator module and back to SDM via A2 terminal. voltage drop between two terminals is used to calculate resistance of inflator module. In order for SDM to set DTC 22, certain criteria must be met:

• Resistance in driver-side inflator module circuit must be less than specified.
• No higher priority malfunctions were detected during previous self tests.
• No crank signal is present.

If this fault is occurring intermittently, most probable causes are a malfunctioning shorting bar in driver-side inflator module connector or a damaged wire/terminal in SIR wiring harness.

1. If a short circuit exists between driver-side high and passenger-side high circuits, DTC 16 will also be recorded by SDM. Reason for this is that these two circuits have parallel current paths.
2. Discriminates between a faulty driver-side inflator module and a faulty SIR wiring harness.
3. Checks for a short circuit between driver-side high and driver-side low circuits.
4. Checks for a short circuit between driver-side high and passenger-side low circuits.
5. Discriminates between a faulty driver-side inflator module and a faulty SIR coil assembly.

Fig 1: DTC 22 - Driver Initiator Circuit Resistance Low

Courtesy of GENERAL MOTORS CORP.