Test Notes

Normal Operation
The diagnostic monitor measures the voltage at pin 11 (Circuit 614 GY/O) of the diagnostic monitor connector. The voltage at pin 11 varies with charging system voltage (the expected voltage at pin 11 is shown in the chart below.

Pin 11 Voltage System Voltage
1.9 9.0
2.0 9.5
2.1 10.0
2.2 10.5
2.3 11.0
2.4 11.5
2.5 12.0
2.6 12.5
2.7 13.0
2.7 13.5
2.9 14.0
3.0 14.5
3.1 15.0
3.2 15.5
3.3 16.0

Note that Circuit 614 is connected to Circuit 615 (GY/W) through the driver side air bag. Also, note that Circuit 615 is connected to the primary crash sensor feed Circuits 617 (PK/O) and 619 (PK/W)) through a diode inside the diagnostic monitor. If the diagnostic monitor measures a voltage of 2.0 volts or less at pin lithe monitor will flash out code 13 to indicate a possible short to ground on this circuit (see 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 short to ground is corrected, the voltage at pin 11 will return to normal and a fault code 51 will flash, indicating an open thermal fuse (see Fault Code 51 for details).

NOTE: Fault code 13 will flash only while the short to ground is present.

Possible Causes
Low voltage at diagnostic monitor pin 11 can be caused by:
1. A short to ground within the wiring harness or Circuits 614 (GY/O), 615 (GY/W), 623 (P/W), 617 (PK/O) or 619 (PK/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 ground within one or more of the crash sensors causing Circuits 617 (PK/O) and 619 (PK/W) to be shorted to ground.
5. An internal short to case ground within the driver side air bag.

NOTE: Circuits 617 (PK/O) and 619 (PK/W) are connected together inside the diagnostic monitor. Therefore, a short to ground on any of these circuits will short all of the circuits to ground.