Test Notes and Schematics

CHARGING SYSTEM VOLTAGE






Electrical Schematic-Diagnostic Trouble Code 13


Normal Operation
The diagnostic monitor measures the voltage at Pins 11 and 12 of the diagnostic monitor connector. The voltage at these pins varies with charging system voltage (the expected voltages at Pins 11 and 12 are shown in the charging system voltage chart above. If the diagnostic monitor measures a voltage of 2.0 volts or less at Pins 11 and 12, the monitor will flash out code 13 to indicate a possible short to ground on these circuits (refer to Possible Causes below for additional circuits that may be shorted to ground). When flashing code 13, the diagnostic monitor blows its internal thermal fuse. This disables the air bag deployment circuit. if the voltage at Pins 11 and 12 returns to normal, a diagnostic trouble code 51 will be present due to the open thermal fuse (refer to Diagnostic Trouble Code 51). DTC 51: Air Bag Diagnostic Monitor Internal Thermal Fuse Blown

NOTE: Diagnostic Trouble Code 13 will flash only while the short to ground is present.

Possible Causes
Low voltage at diagnostic monitor Pins 11 and 12 can be caused by:
1. A short to ground within the wiring harness on Circuits 614 (GY/O), 615 (GY/W), 616 (PK/BK) - (passenger bag vehicles only) or 623 (P/W) causing the diagnostic voltage to drop.
2. An internal short to ground within the clockspring assembly causing the driver side air bag circuit(s) to be shorted to ground.
3. An internal short to ground within the safing sensor causing Circuit 614 (GY/O) or 623 (P/W) to be shorted to ground.
4. An internal short to case ground within the driver side or passenger side air bag.