Pinpoint Test D: LFC 25/DTC B1871 - Passenger Air Bag Deactivate Module Fault
- D1 CHECK FOR ON-DEMAND AND CONTINUOUS DTCs WARNING: Restraint system diagnostic tools are for service only. Tools must be removed prior to operating the vehicle over the road. Failure to remove restraint system diagnostic tools could result in injury and possible violation of vehicle safety standards.WARNING: Never probe the connectors on the air bag module. Doing so can result in air bag deployment, which can result in personal injury.NOTE: After diagnosing or repairing a supplemental restraint system (SRS), the restraint system diagnostic tools must be removed before operating the vehicle over the road.NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
- Enter the following diagnostic mode on the scan tool: Retrieve/Record On-Demand DTCs.
- Enter the following diagnostic mode on the scan tool: Retrieve/Record Continuous DTCs.
- Was DTC B1871 retrieved during the on-demand self test?
Yes : This is a hard fault. The fault condition is still present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self test. Go to D2.
No : This is an intermittent fault. The fault condition is not present at this time. Go to D6.
- D2 CHECK THE PAD SWITCH "ON" POSITION
- Key in OFF position.
- Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Disconnect: RCM C2041.
- Place the PAD switch in the "ON" position.
- Measure the resistance between RCM C2041-8, circuit 1112 (WH/LB), harness side and RCM C2041-21, circuit 649 (BK/OG), harness side.
- Is the resistance between 900 and 1100 ohms?
Yes : Go to D3.
No : Go to D4.
- D3 CHECK THE PAD SWITCH "OFF" POSITION
- Place the PAD switch in the "OFF" position.
- Measure the resistance between RCM C2041-8, circuit 1112 (WH/LB), harness side and RCM C2041-21, circuit 649 (BK/OG), harness side.
- Is the resistance between 400 and 600 ohms?
Yes : INSTALL and CONFIGURE a new RCM. REFER to RESTRAINTS CONTROL MODULE (RCM) . Go to D7.
No : Go to D4.
- D4 CHECK CIRCUIT 1112 (WH/LB) FOR A SHORT TO BATTERY
- Disconnect: PAD Switch C2099.
- Repower the system. Do not prove out the system at this time. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Key in ON position.
- Measure the voltage between PAD C2099-6, circuit 1112 (WH/LB), harness side and ground.
- Is the voltage less than 0.2 volt?
Yes : Go to D5.
No : REPAIR circuit 1112 (WH/LB). Go to D7.
- D5 CHECK CIRCUIT 1112 (WH/LB) FOR AN OPEN
- Key in OFF position.
- Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Measure the resistance between RCM C2041-8, circuit 1112 (WH/LB), harness side and PAD switch C2099-6, circuit 1112 (WH/LB), harness side.
- Is the resistance less than 5 ohms?
Yes : INSTALL a new PAD switch. REFER to PASSENGER AIR BAG DEACTIVATION (PAD) SWITCH . Go to D7.
No : REPAIR circuit 1112 (WH/LB). Go to D7.
- D6 CHECK FOR AN INTERMITTENT FAULT
- Key in OFF position.
- Enter the following diagnostic mode on the scan tool: On-Demand Self Test.
- Was DTC B1871 retrieved during the on-demand self test?
Yes : This is a hard fault. The fault condition is now present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self test. Go to D2.
No : CHECK for causes of intermittent faults on circuit 1112 (WH/LB). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. REPAIR any intermittent concerns found. Go to D7.
- D7 CHECK FOR ADDITIONAL DTCs
- Refer to the continuous DTCs recorded during Step D1.
- Were any continuous DTCs retrieved during Step D1 ?
Yes : Do not clear any DTCs until all DTCs have been resolved. Go to the RESTRAINTS CONTROL MODULE (RCM) DIAGNOSTIC TROUBLE CODE (DTC) PRIORITY TABLE for pinpoint test direction.
No : RECONNECT the system. If previously directed to deactivate the system, REACTIVATE the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . REPOWER the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING . PROVE OUT the system. CLEAR all DTCs.