Pinpoint Test D: LFC 15/DTC B 1887—
Driver Air Bag Circuit Shorted to Ground
Normal Operation
The restraints control module (RCM) checks for driver air bag circuit shorts to ground by monitoring the
voltage of circuits 614 (GY/OG) and 615 (GY/WH) at pins 3 and 4. If the RCM detects a short to
ground on either of these pins, it will store a diagnostic trouble code (DTC) B1887 in memory and flash
a lamp fault code (LFC) 15 (or higher priority code if one exists) on the air bag indicator.
Possible Causes
A driver air bag circuit short to ground can be caused by:
za short to ground on circuit 614 (GY/OG).
z a short to ground on circuit 615 (GY/WH).
z a short to ground on the clockspring (14A664).
z a short to ground on the driver air bag module.
z an RCM internal concern.
PINPOINT TEST D: LFC 15/DTC B1887 — DRIVER AIR BAG CIRCUIT
SHORTED TO GROUND system. PROVE
OUT the system.
REFER to
Air Bag Supplemental
Restraint System
(SRS) in this
section. CLEAR
all DTCs. Test Step Result / Action to
Take D1 CHECK FOR A HARD OR INTERMITTENT DTC
z
Key in OFF position.
z Connect the diagnostic tool. Scan Tool
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool:
Retrieve/Clear Continuous DTCs.
z Retrieve and record any continuous DTCs for use later in this
pinpoint test.
z Enter the following diagnostic mode on the diagnostic tool: On-
Demand Self Test.
z Was DTC B1887 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
D5 . Klj . 10 ba
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D2 CHECK THE DRIVER AIR BAG MODULE
WARNING: If the supplemental restraint system (SRS) is
being serviced, the system must be deactivated and restraint
system diagnostic tools must be installed. Refer to Air Bag Supplemental Restraint System (SRS) in this section.
The air bag restraint system diagnostic tools must be removed
and the air bag modules reconnected when the system is
reactivated to avoid non- deployment in a collision, resulting in
possible personal injury. NOTE: Diagnostics or repairs are not to
be performed on a seat equipped with a seat side air bag with the
seat in the vehicle. Prior to attempting to diagnose or repair a seat
concern when equipped with a seat side air bag, the seat must be
removed from the vehicle and the restraint system diagnostic tools
must be installed in the seat side air bag electrical connectors. The
restraint system diagnostic tools must be removed prior to
operating the vehicle over the road. NOTE: After diagnosing or
repairing an SRS, the restraint system diagnostic tools must be
removed before operating the vehicle over the road. NOTE:
After diagnosing or repairing a seat system, 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.
z Key in OFF position.
z Deactivate the system. Refer to Air Bag Supplemental Restraint System (SRS) in the Diagnosis and Testing portion of this section.
z Key in OFF position.
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool: On-
Demand Self Test.
z Was DTC B1887 retrieved? Yes
GO to
D3 .
No
INSTALL a new
driver air bag
module. GO to D6 .
D3 CHECK THE DRIVER AIR BAG MODULE CIRCUIT
z
Key in OFF position.
z Disconnect: RCM C2041.
z NOTE: Do not separate or remove shorting bars from RCM C2041.
z Measure the resistance between RCM C2041 pin 3, circuit 614
(GY/OG), harness side and RCM C2041 pin 21, circuit 397
(BK/WH), harness side.
z Is the resistance less than 10,000 ohms? Yes
GO to
D4 .
No
INSTALL a new
RCM. GO to D6 .
D4 CHECK THE DRIVER AIR BAG MODULE WIRING AND THE
CLOCKSPRING z
Disconnect: Driver Air Bag Module C216.
z Disconnect: Clockspring C218b.
z Inspect all crimps, terminals, wires and connectors in circuit 614
(GY/OG) feeding the RCM pin 3, circuit 615 (GY/WH) feeding pin 4,
the clockspring C218b. Check for pinched wires and damaged
connector pin terminals.
z Was any damage found? Yes
REPAIR as
necessary. GO to
D6
.
No
GO to D6 . Klj . 11 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...