Airbag code 51

[road_rascal]

The air bag light in my '01 is flashing 5 times, then 3, then it stays on (so I guess it means a code 51). I only found one other post:
"It's more likely that it's a code 51 which indicates a "Driver's Seat Belt Buckle Switch" failure."
Anyone else have this show up? I looked under the front seats and I didn't see any connectors loose. I also can't seem to the info on my Ford service DVD's either. Thanks for the help.

[mundy5]

Actually, according to your description, you have a code 53.

In the DVD, Body -> SRS -> DTC, it states that the LFC (Lamp Fault Codes) is less precise but here is what it says.

B1891

53

22

Air Bag Tone Warning Indicator Circuit Short to Battery
Go To Pinpoint Test D .

B1892

53

22

Air Bag Tone Warning Indicator Circuit Fault
Go To Pinpoint Test E .


PINPOINT TEST D: LFC 53/DTC B1891 — AIR BAG TONE WARNING INDICATOR CIRCUIT SHORT TO BATTERY

CONDITIONS DETAILS/RESULTS/ACTIONS NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough Inspection and Verification before proceeding with the Pinpoint Test. D1 CHECK FOR A HARD OR INTERMITTENT DTC 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.
Retrieve Continuous DTCs Retrieve and record any continuous DTCs for use later in this pinpoint test.

On-Demand Self Test

• Was the DTC B1891 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 D4 .
D2 CHECK THE AIR BAG TONE WARNING INDICATOR CIRCUIT

Deactivate the system. Refer to Supplemental Restraint System (SRS) Deactivation and Reactivation in this section.

RCM C231
Instrument Cluster Module C240



Measure the voltage between RCM C231 pin 11, circuit 1083 (LB/BK), harness side and ground.

• Is the voltage less than 0.2 volt?

Yes GO to D3 .

No REPAIR the short to battery on the circuit. GO to D5 .
D3 CHECK THE AIR BAG TONE WARNING INDICATOR CIRCUIT


Instrument Cluster Module C240

Install a fused jumper between RCM C231 pin 11, circuit 1083 (LB/BK), harness side and ground


NOTE: The safety belt warning lamp will turn off after one minute regardless of circuit state.

• Verify the safety belt warning lamp operates.

• Does the safety belt warning lamp operate?

Yes INSTALL a new RCM. REFER to Restraints Control Module (RCM) . GO to D5 .

No INSTALL a new instrument cluster module.GO to D5 .
D4 CHECK FOR AN INTERMITTENT FAULT


On-Demand Self Test

• Was the DTC B1891 retrieved during the on-demand self test?

Yes GO to D2 .

No CHECK for causes of intermittent short to ground or open on circuit 1083 (LB/BK). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. REPAIR any intermittent concerns found. GO to D5 .
D5 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 in this section 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 in this section. REPOWER the system. REFER to Supplemental Restraint System (SRS) Depowering and Repowering in this section. PROVE OUT the system. CLEAR all DTCs.

Pinpoint Test E: LFC 53/DTC B1892 — Air Bag Tone Warning Indicator Circuit Shorted to Ground or Open
Normal Operation
The restraints control module (RCM) monitors its connection to the instrument cluster module at C2041a pin 11. This connection is used to signal a chime if the air bag indicator is inoperative and another SRS fault exists. If the RCM detects a short to ground or open on the connection to the instrument cluster module, it will store diagnostic trouble code (DTC) B1892 in memory and flash lamp fault code (LFC) 53 (or a higher priority code if one exists) on the air bag indicator.
Possible Causes
An air bag tone warning indicator circuit short to ground or open can be caused by:

• Wiring, terminals, or connectors.
• A damaged or inoperative instrument cluster module.
• RCM.

PINPOINT TEST E: LFC 53/DTC B1892 — AIR BAG TONE WARNING INDICATOR CIRCUIT SHORTED TO GROUND OR OPEN

CONDITIONS DETAILS/RESULTS/ACTIONS 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 A HARD OR INTERMITTENT DTC 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.
Retrieve Continuous DTCs Retrieve and record any continuous DTCs for use later in this pinpoint test.

On-Demand Self Test

• Was the DTC B1892 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 E2 .

No This is an intermittent fault. The fault condition is not present at this time. GO to E5 .
E2 CHECK THE AIR BAG TONE WARNING INDICATOR CIRCUIT FOR GROUND SHORT

Depower the system. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in this section.

RCM C231
Instrument Cluster Module C240

Measure the resistance between RCM C231 pin 11, circuit 1083 (LB/BK), harness side and RCM C231 pin 10, circuit 649 (BK/OG), harness side.

• Is the resistance greater than 1,000,000 ohms?

Yes GO to E3 .

No REPAIR the ground short on circuit 1083 (LB/BK). GO to E6 .
E3 CHECK THE AIR BAG TONE WARNING INDICATOR CIRCUIT

Measure the resistance between RCM C231 pin 11, circuit 1083 (LB/BK), harness side and instrument cluster module C240 pin 1, circuit 1083 (LB/BK), harness side.

• Is the resistance greater than 10 ohms?

Yes REPAIR circuit 1083 (LB/BK). GO to E6 .

No GO to E4 .
E4 CHECK THE AIR BAG TONE WARNING INDICATOR
Instrument Cluster Module C240 Deactivate the system. Refer to Supplemental Restraint System (SRS) Deactivation and Reactivation in this section.




Measure the voltage at RCM C231 pin 11, circuit 1083 (LB/BK).

• Is the voltage less than 1.0 volt?

Yes INSTALL a new instrument cluster module. GO to E6 .

No INSTALL a new RCM. REFER to Restraints Control Module (RCM) . GO to E6 .
E5 CHECK FOR AN INTERMITTENT FAULT


On-Demand Self Test

• Was the DTC B1892 retrieved during the on-demand self test?

Yes GO to E2 .

No CHECK for causes of intermittent short to ground or open on circuit 1083 (LB/BK). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. REPAIR any intermittent concerns found. GO to E6 .
E6 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) Priority Table in this section 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 in this section. REPOWER the system. REFER to Supplemental Restraint System (SRS) Depowering and Repowering in this section. PROVE OUT the system. CLEAR all DTCs.

[road_rascal]

Dammit. I can't type worth a crud at my work comp. It is a code 51, not 53. Sorry for the confusion. Oh- I don't have any DTC on the MIL.

[mundy5]

Originally Posted by road_rascal

The air bag light in my '01 is flashing 5 times, then 3, then it stays on (so I guess it means a code 51).

Maybe I am not understanding you correctly, but you wrote on the first post that you saw 5 blinks, then 3 blinks. tha'ts not a 51 unless you meant 5 blinks then 1 blink.

anyway, your scan tool that is sold over the counter does not read srs codes. that's why it doesn't pick up any dtc on the mil. you need a much more expensive scan tool. Anyway, if you are absolutely sure its code 51, then it is listed below. it all looks like the driver buckle switch is bad. Go to the body section of the dvd and look at the SRS section. Then go to the LFC (Lamp Fault Codes) section. The pinpoint tests are too long to post here.

B2432 51 11 Driver Safety Belt Buckle Switch Circuit Open Go To Pinpoint Test L .
B2433 51 11 Driver Safety Belt Buckle Switch Circuit Short to Battery Go To Pinpoint Test M .
B2434 51 11 Driver Safety Belt Buckle Switch Circuit Short to Ground Go To Pinpoint Test N .
B2435 51 11 Driver Safety Belt Buckle Switch Resistance Out of Range Go To Pinpoint Test O .

Scan tools normally only read P codes. All of these are proprietary B codes from Ford.

[road_rascal]

Yes- it is a code 51 (I shouldn't type before I get a cup of coffee in the morning). Sorry for the misunderstanding. Thanks for the help- I'll check out the service DVD when I get home.

[mundy5]

you're welcome. that's why we are here. i'm sure i'll be needing help soon as well.