DESCRIPTION & OPERATION
| WARNING | Accidental air bag deployment is possible. Personal injury may result. Read and follow all WARNINGS and AIR BAG SAFETY PRECAUTIONS before working on air bag system or related components. |
The Supplemental Restraint System (SRS), also known as air bag system, is designed to provide increased accident protection for driver and passenger by deploying front air bags and front seat belt pretensioners in a front-end collision or side air bags in a side collision. The air bags deploy in about 40 milliseconds, after impact sensors close. Air bag system is designed to be used with 3-point seat belts.
During a front-end collision, the air bag Restraints Control Module (RCM), using input from crash sensor, discriminates between an event that warrants air bag deployment and an event that does not. In a crash of sufficient force, the RCM signals the air bag modules and seat belt pretensioners to simultaneously deploy.
During a side or lateral collision, the RCM using inputs from right and/or left side crash sensor, discriminates between an event that warrants air bag deployment and an event that does not. In a crash of sufficient force, the RCM signals the right and/or left side (seat) air bag module to deploy.
Air bag system includes the following components: RCM, safing sensor (located inside the RCM), back-up power supply (also located inside the RCM), right and left side crash sensors (beneath carpet, under front seats), driver-side air bag module, passenger-side air bag module, side air bag modules (located behind outboard bolster of driver and passenger seat backs), left and right front seat belt pretensioners, AIR BAG warning light, clockspring and associated wiring harnesses. See COMPONENT LOCATIONS .
SYSTEM OPERATION CHECK
- When checking air bag system operation (also known as prove out system), and upon completion of each diagnostic test, check for faults in air bag system. To check system, turn ignition switch to RUN position. If AIR BAG warning light illuminates for 6 seconds and then goes out, air bag system is functioning properly and no faults exist.
- If a fault is detected in air bag system during initial system check, AIR BAG warning light will flash a code sequence, indicating a fault in system. Count number of flashes after fault code has cycled twice. Number of flashes represents a code number used to diagnose air bag system. See «DIAGNOSTICS»(ref-150665-S11384281222002112000000) . If AIR BAG warning light either fails to light or stays on continuously, go to «DIAGNOSTIC SYMPTOMS»(ref-150665-S24223863982002112000000) .
- If a system fault exists and AIR BAG warning light fails to light, an audible tone will be heard, indicating AIR BAG warning light is malfunctioning and service is required.
Description
During normal operation, the AIR BAG warning light will be continuously illuminated for 6 seconds after the ignition switch is placed in RUN position and after 5 cycles of Light Flash Code (LFC) if a fault exists. Be sure to cycle ignition switch and look for a continuous AIR BAG warning light without LFC.
Restraints Control Module (RCM) will communicate Diagnostic Trouble Codes (DTCs) through scan tool using Data Link Connector (DLC). If scan tool displays NO COMMUNICATION when retrieving continuous codes, go to TEST AJ: NO COMMUNICATION WITH RCM .
Restraints Control Module (RCM) checks driver-side air bag module circuits for short to ground by monitoring voltage at RCM harness connector C2041A, terminals No. 3 (Gray/Orange wire) and No. 4 (Gray/White wire). If RCM detects short to ground on either terminal, it will store Diagnostic Trouble Code (DTC) B1887 in memory and flash Code 15 on AIR BAG warning light.
Restraints Control Module (RCM) checks driver-side air bag module circuits for short to battery or ignition voltage by monitoring voltage at RCM harness connector C2041A, terminals No. 3 (Gray/Orange wire) and No. 4 (Gray/White wire). If RCM detects short to battery or ignition voltage on either terminal, it will store Diagnostic Trouble Code (DTC) B1916 in memory and flash Code 15 on AIR BAG warning light.
Restraints Control Module (RCM) checks passenger-side air bag module circuits for short to ground by monitoring voltage at RCM harness connector C2041A, terminals No. 6 (Light Blue/Orange wire) and No. 7 (Pink/Black wire). If RCM detects short to ground on either terminal, it will store Diagnostic Trouble Code (DTC) B1888 in memory and flash Code 16 on AIR BAG warning light.
Restraints Control Module (RCM) checks passenger-side air bag module circuits for short to battery or ignition voltage by monitoring voltage at RCM harness connector C2041A, terminals No. 6 (Light Blue/Orange wire) and No. 7 (Pink/Black wire). If RCM detects short to battery or ignition voltage on either terminal, it will store Diagnostic Trouble Code (DTC) B1925 in memory and flash Code 16 on AIR BAG warning light.
Restraints Control Module (RCM) monitors voltage in left seat belt pretensioner circuits. If RCM detects a short to battery or ignition, it will store Diagnostic Trouble Code (DTC) B1878 in memory and flash Code 17 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance in left seat belt pretensioner circuits. If RCM detects a short to ground, it will store Diagnostic Trouble Code (DTC) B1879 in memory and flash Code 17 on AIR BAG warning light.
Restraints Control Module (RCM) monitors voltage in right seat belt pretensioner circuits. If RCM detects a short to battery or ignition, it will store Diagnostic Trouble Code (DTC) B1882 in memory and flash Code 18 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance or seat belt pretensioner circuits. If RCM detects a short to ground, it will store Diagnostic Trouble Code (DTC) B1883 in memory and flash Code 18 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance between ground connections at its housing and reference ground at RCM connector C2041A, terminal No. 21. If RCM detects resistance more than 100 ohms, it will store Diagnostic Trouble Code (DTC) B1921 in memory and flashes Code 21 on AIR BAG warning light.
TEST K: INCORRECT VEHICLE IDENTIFICATION CODE (DTC C1414)
Note. Before proceeding, see AIR BAG SAFETY PRECAUTIONS .
Restraints Control Module (RCM) monitors voltage on RCM harness connector C2041A, terminals No. 10, 13 and 14 to determine if RCM is installed on the correct vehicle. If RCM detects an incorrect voltage on any of these terminals, it will store Diagnostic Trouble Code (DTC) C1414 in memory and flash Code 29 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance of driver-side air bag ignitor by measuring resistance between RCM harness connector C2041A, terminals No. 3 (Gray/Orange wire, circuit No. 614) and No. 4 (Gray/White wire, circuit No. 614). If RCM detects high resistance between these terminals, it will store Diagnostic Trouble Code (DTC) B1932 in memory and flash Code 32 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance of passenger-side air bag ignitor by measuring resistance between RCM harness connector C2041A, terminals No. 6 (Light Blue/Orange wire, circuit No. 607) and No. 7 (Pink/Black wire, circuit No. 616). If RCM detects high resistance between these terminals, it will store Diagnostic Trouble Code (DTC) B1933 in memory and flash Code 33 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance of driver-side air bag ignitor by measuring resistance between RCM harness connector C2041A, terminals No. 3 (Gray/Orange wire, circuit No. 614) and No. 4 (Gray/White wire, circuit No. 615). If RCM detects low resistance between these terminals, it will store Diagnostic Trouble Code (DTC) B1934 in memory and flash Code 34 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance of passenger-side air bag ignitor by measuring resistance between RCM harness connector C2041A, terminals No. 6 (Light Blue/Orange wire, circuit No. 607) and No. 7 (Pink/Black wire, circuit No. 616). If RCM detects low resistance between these terminals, it will store Diagnostic Trouble Code (DTC) B1935 in memory and flash Code 35 on AIR BAG warning light.
Restraints Control Module (RCM) checks left side air bag module circuits for short to battery or ignition by monitoring voltage at RCM harness connector C2041B, terminals No. 2 (White/Light Blue wire) and No. 3 (Brown/Light Blue wire). If RCM detects short to battery or ignition voltage, it will store Diagnostic Trouble Code (DTC) B1992 in memory and flash Code 36 on AIR BAG warning light.
Restraints Control Module (RCM) checks left side air bag module circuits for short to ground by monitoring voltage at RCM harness connector C2041B, terminals No. 2 (White/Light Blue wire) and No. 3 (Brown/Light Blue wire). If RCM detects resistance less than 10 k/ohms at either terminal, it will store Diagnostic Trouble Code (DTC) B1993 in memory and flash Code 36 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance of left side air bag module circuit loop and air bag igniter at RCM connector C2041B terminals No. 2 (White/Light Blue wire) and No. 3 (Brown/Light Blue wire). If RCM detects resistance more than 3.6 ohms, it will store Diagnostic Trouble Code (DTC) B1994 in memory and flash Code 36 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance of left side air bag module circuit loop and air bag igniter at RCM harness connector C2041B terminals No. 2 (White/Light Blue wire) and No. 3 (Brown/Light Blue wire). If RCM detects resistance less than 0.7 ohm, it will store Diagnostic Trouble Code (DTC) B1995 in memory and flash Code 36 on AIR BAG warning light.
Restraints Control Module (RCM) checks right side air bag module circuits for short to battery or ignition by monitoring voltage at RCM harness connector C2041B, terminals No. 5 (White/Yellow wire) and No. 6 (Brown/Yellow wire). If RCM detects battery or ignition voltage, it will store Diagnostic Trouble Code (DTC) B1996 in memory and flash Code 37 on AIR BAG warning light.
Restraints Control Module (RCM) checks right side air bag module circuits for short to ground by monitoring resistance to ground at RCM harness connector C2041B, terminals No. 5 (White/Yellow wire) and No. 6 (Brown/Yellow wire). If RCM detects resistance less than 10 k/ohms at either terminal, it will store Diagnostic Trouble Code (DTC) B1997 in memory and flash Code 37 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance of right side air bag module circuit loop and air bag igniter at RCM harness connector C2041B terminals No. 5 (White/Yellow wire) and No. 6 (Brown/Yellow wire). If RCM detects resistance more than 3.6 ohms, it will store Diagnostic Trouble Code (DTC) B1998 in memory and flash Code 37 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance of right side air bag module circuit loop and air bag igniter at RCM harness connector C2041B terminals No. 5 (White/Yellow wire) and No. 6 (Brown/Yellow wire). If RCM detects resistance less than 0.7 ohm, it will store Diagnostic Trouble Code (DTC) B1999 in memory and flash Code 37 on AIR BAG warning light.
Restraints Control Module (RCM) monitors 2-wire current loop to left side crash sensor for signal that is out of expected range. If RCM detects an out-of-range signal, indicating a sensor mounting failure, it will store Diagnostic Trouble Code (DTC) B2441 in memory and flash Code 42 on AIR BAG warning light.
Restraints Control Module (RCM) monitors 2-wire current loop to right side crash sensor for signal that is out of expected range. If RCM detects an out-of-range signal, indicating a sensor mounting failure, it will store Diagnostic Trouble Code (DTC) B2440 in memory and flash Code 43 on AIR BAG warning light.
Restraints Control Module (RCM) monitors 2-wire current loop to right side crash sensor for signal that is out of expected range. If RCM detects an out-of-range signal, indicating a sensor communication fault, it will store Diagnostic Trouble Code (DTC) U2017 in memory and flash Code 44 on AIR BAG warning light.
Restraints Control Module (RCM) monitors 2-wire current loop to left side crash sensor for signal that is out of expected range. If RCM detects an out-of-range signal, indicating a sensor communication fault, it will store Diagnostic Trouble Code (DTC) U2018 in memory and flash Code 45 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance in left seat belt pretensioner circuits. If RCM detects resistance that is out of expected range (high or low), it will store Diagnostic Trouble Code (DTC) B1885 or 1877 in memory and flash Code 46 on AIR BAG warning light.
Restraints Control Module (RCM) monitors resistance in right seat belt pretensioner circuits. If RCM detects resistance that is out of expected range, it will store Diagnostic Trouble Code (DTC) B1881 or 1886 in memory and flash Code 47 on AIR BAG warning light.
Restraints Control Module (RCM) monitors 2-wire current loop to left side crash sensor for signal that is out of expected range. If RCM detects an out-of-range signal, indicating an internal fault, it will store Diagnostic Trouble Code (DTC) B2444 in memory and flash Code 48 on AIR BAG warning light.
Restraints Control Module (RCM) monitors 2-wire current loop to right side crash sensor for signal that is out of expected range. If RCM detects an out-of-range signal, indicating an internal fault, it will store Diagnostic Trouble Code (DTC) B2445 in memory and flash Code 49 on AIR BAG warning light.
AIR BAG warning light is designed to illuminate for 6 seconds when ignition switch is turned to RUN position. The initial 6-second illumination is normal and is call prove-out. The AIR BAG warning light is then used to warn vehicle operator that there is a fault in the air bag system.
Restraints Control Module (RCM) monitors AIR BAG warning light for open and short to ground conditions. If RCM detects open or short to ground in AIR BAG warning light circuit, it will store Diagnostic Trouble Code (DTC) 1869 in memory. If RCM detects AIR BAG warning light failure in addition to another air bag system failure, it will send signal to instrument cluster to produce 5 sets of 5 tone bursts.
AIR BAG warning light is designed to illuminate for 6 seconds when ignition switch is turned to RUN position. The initial 6 second illumination is normal and is call prove-out. The AIR BAG warning light is then used to warn vehicle operator that there is a fault in the air bag system.
Restraints Control Module (RCM) monitors AIR BAG warning light for short to battery voltage conditions. If RCM detects short to battery voltage in AIR BAG warning light circuit, it will store Diagnostic Trouble Code (DTC) 1870 in memory. In RCM detects AIR BAG warning light failure in addition to another air bag system failure, it will send signal to instrument cluster to produce 5 sets of 5 tone bursts.
Restraints Control Module (RCM) monitors its connection to instrument cluster at RCM harness connector C2041A, terminal No. 26 (Light Blue/Black wire). This connection is used to signal a chime if AIR BAG warning light is inoperative and another air bag system fault exists. If RCM detects a short to battery or ignition in connection to instrument cluster, it will store Diagnostic Trouble Code (DTC) B1891 in memory.
Restraints Control Module (RCM) monitors its connection to instrument cluster at RCM harness connector C2041A, terminal No. 26 (Light Blue/Black wire). This connection is used to signal a chime if AIR BAG warning light is inoperative and another air bag system fault exists. If RCM detects a short or open in connection to instrument cluster, it will store Diagnostic Trouble Code (DTC) B1892 in memory.
Restraints Control Module (RCM) communicates with scan tool using International Standards Organization (ISO) 9141 communication mode through Data Link Connector (DLC).