Chart D SDM Cannot Communicate With Scan Tool

Diagnostic Chart:

Diagnostic Chart (Cont'd):

Circuit Schematic:

CIRCUIT DESCRIPTION
When the ignition switch is first turned On, "Ignition 1" voltage is applied to the AIR BAG warning lamp which is connected to the "WARN 1" terminal A9 of the Sensing & Diagnostics Module (SDM). The AIR BAG fuse applies system voltage to the "Ignition 1" input terminal A7 of the SDM. The SDM responds by flashing the AIR BAG warning lamp seven times by providing a ground. If "Ignition 1" is outside of normal operating voltage range (approximately 6.64 VDC to 16 VDC), the AIR BAG warning lamp will come On solid with no diagnostic trouble codes set.

CHART TEST DESCRIPTION
The numbers below refer to the step numbers listed on the diagnostic chart.
1. This step checks to make sure the Saturn Portable Diagnostic (Scan) (PDT) Tool is properly connected to the DLC.
2. This step verifies the proper software package.
4. This step checks for a short to ground on the "Serial Data" circuit.
7. This step checks for an open in the "Serial Data" circuit.
8. This step checks for a short to the battery, on the "Serial Data" circuit.



CHART D
Was the "SIR Diagnostic System Check" performed?

When measurements are requested in this chart, use (Saturn Tool) SA 911 14NE DVM with correct terminal adapter from SA 9206Z. When a wire connector or terminal repair is requested, use the proper repair parts.