Pinpoint Test H: LFC 27/DTC B1890 - Passenger Air Bag Deactivation (Pad) Warning Lamp Short To Battery

WARNING: This page is about a different car, the 2006 Ford Pickup, 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough Inspection and Verification before proceeding with the Pinpoint Test.

H1 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 B1890 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 H2.

No : This is an intermittent fault. The fault condition is not present at this time. Go to H4.
H2 CHECK THE PAD SWITCH WARNING LAMP
- Place the PAD switch in the "OFF" position.
- Does the PAD lamp illuminate correctly?
Yes : INSTALL and CONFIGURE a new RCM. REFER to RESTRAINTS CONTROL MODULE (RCM) . Go to H5.

No : Go to H3.
H3 CHECK CIRCUIT 1113 (YE/LG) FOR A SHORT TO BATTERY
- Key in OFF position.
- Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Disconnect: RCM C2041.
- 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 switch C2099-3, circuit 1113 (YE/LG), harness side and ground.
  
  Fig 1: Checking Circuit 1113 (YE/LG) For Short To Battery
  Courtesy of FORD MOTOR CO.
- Is the voltage less than 0.2 volt?
Yes : INSTALL a new PAD switch. REFER to PASSENGER AIR BAG DEACTIVATION (PAD) SWITCH . Go to H5.

No : REPAIR circuit 1113 (YE/LG). Go to H5.
H4 CHECK FOR AN INTERMITTENT FAULT
- Key in OFF position.
- Enter the following diagnostic mode on the scan tool: On-Demand Self Test.
- Was DTC B1890 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 H2.

No : CHECK for causes of the intermittent short to battery or ignition on circuit 1113 (YE/LG). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. REPAIR any intermittent concerns found. Go to H5.
H5 CHECK FOR ADDITIONAL DTCs
- Refer to the continuous DTCs recorded during Step H1.
- Were any continuous DTCs retrieved during Step H1 ?
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.