Pinpoint Test E: DTC B1890 - Pad Warning Lamp Circuit Short To Battery

WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. 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.

E1 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.

WARNING: The safety belt pretensioner is a pyrotechnic device. Always wear safety glasses when repairing an air bag equipped vehicle and when handling a safety belt buckle pretensioner or safety belt retractor pretensioner. Never probe a pretensioner electrical connector. Doing so could result in pretensioner or air bag deployment and could result in personal injury.

NOTE: After diagnosing or repairing an 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: On-Demand Self Test.
- 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 is corrected and the DTC is no longer retrieved during the on-demand self test. GO to E2.

No : This is an intermittent fault. The fault condition is not present at this time. GO to E4.
E2 CHECK CIRCUIT 1632 (TN/LB) FOR A SHORT TO VOLTAGE
- Key in OFF position.
- Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Disconnect: RCM C310a and C310b.
- Disconnect: PAD Indicator C2286.
- 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 indicator C2286-3, circuit 1632 (TN/LB), harness side and ground.
  
  Fig 1: Measuring Voltage Between PAD Indicator C2286 Pin 3, Circuit 1632 And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage less than 0.2 volt?
Yes : GO to E3.

No : REPAIR circuit 1632 (TN/LB). GO to E5.
E3 CHECK THE RCM
- Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Connect: RCM C310a and C310b.
- Repower the system. Do not prove out the system at this time. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Enter the following diagnostic mode on the scan tool: On-Demand Self Test.
  NOTE: DTC B1884 should be retrieved when carrying out the on-demand self test due to an open on circuit 1632 (TN/LB), DTC B1890 should not be retrieved at this time.
- Was DTC B1890 retrieved during the on-demand self test?
Yes : INSTALL a new RCM . REFER to RESTRAINTS CONTROL MODULE (RCM) . GO to E5.

No : INSTALL a new PAD indicator. REFER to PASSENGER AIR BAG DEACTIVATION (PAD) INDICATOR GO to E5.
E4 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 is corrected and the DTC is no longer retrieved during the on-demand self test. GO to E2.

No : CHECK for causes of intermittent short to battery on circuit 1632 (TN/LB). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. ACTIVATE other systems in the same wire harness. REPAIR any intermittent concerns found. GO to E5.
E5 CHECK FOR ADDITIONAL DTCs
- Refer to the continuous DTCs recorded during Step E1.
- Were any continuous DTCs retrieved during Step E1 ?
Yes : Do not clear any DTCs until all DTCs have been resolved. GO to the RESTRAINTS CONTROL MODULE (RCM) DIAGNOSTIC TROUBLE CODE (DTC) TABLE in this article 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.