DTC 13: Air Bag Or Crash Sensor Circuit Shorted to Ground

Electrical Schematic:

Pin 11 Voltage Chart:

Normal Operation
The air bag diagnostic monitor measures the voltage at pin 11 (circuit 944A "GN/W") of the air bag diagnostic monitor connector. The voltage at pin 11 varies with the charging system voltage as shown in the provided chart.

Note that circuit 944A is connected to circuit 937 ("GY") and circuit 939 ("GN/R") through the driver side air bag module, passenger side air bag module and center cowl safing rear air bag sensor. Also, note that circuit 937 and 939 are connected to the RH, LH and center primary crash air bag sensor feed circuits (933 ["BR/GN"], 932 ["BR/R"], and 931 ["BR/BK"]) through diodes inside the air bag diagnostic monitor. If the air bag diagnostic monitor measures a voltage of 2.0 volts or less at pin 11, the air bag diagnostic monitor will flash a 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 air bag diagnostic monitor blows its internal thermal fuse. This disables the air bag deployment circuit. If the voltage at pin 11 returns to normal (because the short to ground no longer exists), a fault code 51 will be present on the air bag warning indicator, due to the open thermal fuse (see DTC 51 for details).

Possible Causes
Low voltage at air bag diagnostic monitor pin 11 can be caused by:
1. A short to ground within the wiring harness on circuits 944A ("GN/W"), 944 ("GN/W"), 944B ("GN/W"), 944D ("GN/W"), 938 ("R"), 937 ("GY"), 939 ("GN/R"), 933 ("BR/GN"), 932 ("BR/R") or 931 ("BR/BK") causing the air bag diagnostic monitor voltage to drop.
2. An internal short to ground within the air bag sliding contact causing the driver side air bag module circuit(s) to be shorted to ground.
3. An internal short to ground within the center cowl safing rear air bag sensor causing circuit 944A ("GN/W"), 944 ("GN/W"), 944B ("GN/W"), 944D ("GN/W"), or 938 ("R") to be shorted to ground.
4. An internal short to ground within one or more of the primary crash air bag sensors causing circuits 933 ("BR/GN"), 932 ("BR/R"), and 931 ("BR/BK") to be shorted to ground.

NOTE: Circuits 933 ("BR/GN"), 932 ("BR/R") and 931 ("BR/BK") are all connected together inside the air bag diagnostic monitor. Therefore, a short to ground on any of these circuits will short all of the circuits to ground.

5. An internal short to case ground within the driver side air bag module or passenger side air bag module.







Pinpoint Test Steps:

13-1 - 13-4:

13-5 - 13-7: