Ford F150 Pickup. Instruction — part 1731

DISABLING & ACTIVATING AIR BAG SYSTEM. Access RCM and disconnect harness connector.
See RESTRAINTS CONTROL MODULE (RCM) under REMOVAL & INSTALLATION. Access
GEM and disconnect harness connector C201A. See GENERIC ELECTRONIC MODULE (GEM)
under REMOVAL & INSTALLATION. Measure resistance between harness side of RCM connector
terminals No. 26 (Light Blue/Black wire, circuit No. 1083) and No. 21 (Black/Orange wire, circuit No.
649). See Fig. 14 . If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10
k/ohms, repair short to ground in Light Blue/Black wire. See WIRING DIAGRAMS . Go to step 6 .

3. Check air bag tone warning indicator circuit

Measure resistance of Light Blue/Black wire between harness side of RCM connector terminal No. 26
and GEM connector C201A, terminal No. 20. See Fig. 14 & Fig. 18 . If resistance is less than 100 ohms,
go to next step. If resistance is more than 100 ohms, repair open in Light Blue/Black wire. Go to step 6 .

4. Check air bag tone warning indicator

Ensure GEM connector C201A is disconnected. Turn ignition switch to RUN position. Measure voltage
between ground and harness side of RCM connector terminal No. 26 (Light Blue/Black wire). See Fig.
14 . If voltage is less than one volt, replace GEM. Go to step 6 . If voltage is more than one volt, replace
RCM. Go to step 6 .

5. Check for intermittent fault

Refer to continuous DTCs recorded in step 1 . If DTC retrieved in step 1 was an intermittent fault, check
for cause of intermittent short to ground or open in Light Blue/Black wire (circuit No. 1083). See
WIRING DIAGRAMS . Attempt to recreate fault by flexing wire harness and cycling ignition switch
frequently. Repair any intermittent problems found. Go to next step. If DTC retrieved in step 1 was not an
intermittent fault. Go to next step.

6. Check for additional DTCs

Refer to continuous DTCs recorded in step 1 . If any continuous DTCs were retrieved, go to diagnostic
trouble code identification table for direction to appropriate test. See DIAGNOSTIC TROUBLE CODE
(DTC) IDENTIFICATION table. DO NOT clear any DTCs until all DTCs have been resolved. If no
continuous DTCs were retrieved, reconnect air bag system. Activate air bag system. See ACTIVATING
SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Clear all DTCs. See CLEARING
FAULT CODES under DIAGNOSTICS.

TEST Q: DRIVER AIR BAG CIRCUIT SHORT TO BATTERY OR IGNITION (DTC B1916)

Description

Restraints Control Module (RCM) driver-side air bag module circuit for shorts to battery or ignition voltage by
monitoring voltage at RCM harness connector terminals No. 3 (Gray/Orange wire) and No. 4 (Gray/White
wire). If RCM detects short to battery or ignition voltage in either terminal, it will store Diagnostic Trouble

NOTE:

Before proceeding, see AIR BAG SAFETY PRECAUTIONS .

2003 Ford Pickup F150

2003 ACCESSORIES/SAFETY EQUIPMENT Air Bag Restraint Systems - F150 Pickup

Code (DTC) B1916 in memory and flash Code 15 on AIR BAG warning light.

Possible Causes

A driver-side air bag ignitor circuit shorted to battery or ignition voltage could be caused by short to battery or
ignition voltage in Gray/Orange wire, short to battery or ignition voltage in Gray/White wire, short to battery or
ignition voltage in clockspring, short to battery or ignition voltage in driver-side air bag module or faulty RCM.

1. Check for hard or intermittent DTC

Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). See USING
SCAN TOOL under DIAGNOSTICS. Turn ignition switch to RUN position. Retrieve and record any
continuous DTCs. See RETRIEVING FAULT CODES under DIAGNOSTICS. Perform on-demand
self-test. See ON-DEMAND SELF-TEST under DIAGNOSTICS. If DTC B1916 was retrieved during
on-demand self-test, fault is hard. Go to next step. If DTC B1916 was not retrieved, fault is intermittent.
Go to step 5 .

2. Check driver-side air bag module

Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM under
DISABLING & ACTIVATING AIR BAG SYSTEM. Turn ignition switch to RUN position. Perform on-
demand self-test. See ON-DEMAND SELF-TEST under DIAGNOSTICS. If DTC B1916 is retrieved,
go to next step. If DTC B1916 is not retrieved, replace driver-side air bag module. See DRIVER-SIDE
AIR BAG MODULE under REMOVAL & INSTALLATION. Go to step 6 .

3. Check driver-side air bag circuit

Turn ignition switch to OFF position. Disconnect driver-side air bag simulator from harness connector.
Access RCM and disconnect harness connector. See

RESTRAINTS CONTROL MODULE (RCM)

under REMOVAL & INSTALLATION. Turn ignition switch to RUN position. Measure voltage between
ground and harness side of RCM connector terminals No. 3 (Gray/Orange wire, circuit No. 614) and No.
4 (Gray/White wire, circuit No. 615). See Fig. 14 . If voltage is more than 0.2 volt, go to next step. If
voltage is less than 0.2 volt, replace RCM. Go to step 6 .

4. Check driver-side air bag wiring & clockspring

Disconnect lower clockspring connector located on bottom of steering column. Inspect all crimps,
terminals, fuses, wires and connectors feeding RCM harness connector terminals No. 3 (Gray/Orange
wire) and No. 4 (Gray/White wire, circuit No. 615), clockspring and clockspring connectors. See
WIRING DIAGRAMS . Also, check for pinched wires and damaged connector terminals. If any damage
is found, repair/replace as necessary and go to step 6 . If no damage is found, go to step 6 .

5. Check for intermittent fault

Refer to continuous DTCs recorded in step 1 . If DTC retrieved in step 1 was an intermittent fault, check

NOTE:

Do not remove or separate shorting bars from RCM harness connector.

2003 Ford Pickup F150

2003 ACCESSORIES/SAFETY EQUIPMENT Air Bag Restraint Systems - F150 Pickup

for cause of intermittent short to battery or ignition voltage in Gray/Orange (circuit No. 614) wire,
Gray/White wire (circuit No. 615) and clockspring assembly. See WIRING DIAGRAMS . Attempt to
recreate fault by flexing wire harness and cycling ignition switch frequently. Repair any intermittent
problems found. Go to next step. If DTC retrieved in step 1 was not an intermittent fault. Go to next step.

6. Check for additional DTCs

Refer to continuous DTCs recorded in step 1 . If any continuous DTCs were retrieved, go to diagnostic
trouble code identification table for direction to appropriate test. See DIAGNOSTIC TROUBLE CODE
(DTC) IDENTIFICATION table. DO NOT clear any DTCs until all DTCs have been resolved. If no
continuous DTCs were retrieved, reconnect air bag system. Activate air bag system. See ACTIVATING
SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Clear all DTCs. See CLEARING
FAULT CODES under DIAGNOSTICS.

TEST R: RCM BRACKET GROUND RESISTANCE HIGH (DTC B1921)

Description

Restraints Control Module (RCM) monitors resistance between ground connections at its housing and reference
ground at RCM connector terminal No. 21. If RCM detects resistance more than 100 ohms, it stores DTC
B1921 in memory and flashes Code 21 on AIR BAG warning light.

Possible Causes

High resistance between RCM housing ground and terminal ground could be caused by improper tightening or
seating of RCM mounting bolts, high resistance in RCM logic ground circuit or faulty RCM.

1. Check for hard or intermittent DTC

Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). See USING
SCAN TOOL under DIAGNOSTICS. Turn ignition switch to RUN position. Retrieve and record any
continuous DTCs. See RETRIEVING FAULT CODES under DIAGNOSTICS. Perform on-demand
self-test. See ON-DEMAND SELF-TEST under DIAGNOSTICS. If DTC B1921 was retrieved during
on-demand self-test, fault is hard. Go to next step. If DTC B1921 was not retrieved, fault is intermittent.
Go to step 6 .

2. Check mounting of RCM

Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM under
DISABLING & ACTIVATING AIR BAG SYSTEM. Remove RCM. See RESTRAINTS CONTROL
MODULE (RCM) under REMOVAL & INSTALLATION. Inspect RCM, mounting bracket and
mounting surface for damage or corrosion. Inspect RCM bracket bolts and ensure bolts are fully seated
and tightened properly. If bracket and mounting surface is okay and mounting bolts are tight, go to next
step. If bracket and mounting surface is not okay and/or mounting bolts are not tight, repair/replace as
necessary. Go to step 7 .

NOTE:

Before proceeding, see AIR BAG SAFETY PRECAUTIONS .

2003 Ford Pickup F150

2003 ACCESSORIES/SAFETY EQUIPMENT Air Bag Restraint Systems - F150 Pickup

3. Check RCM harness connection

Ensure RCM connector is fully connected. If RCM connector is fully connected, go to next step. If RCM
connector is not fully connected, reconnect connector. Go to step 7 .

4. Check vehicle chassis ground

Measure resistance between a known good ground and RCM mounting surface. If resistance more than
100 ohms, repair grounding system and go to step 7 . If resistance is less than 100 ohms, go to next step.

5. Check ground circuit for open

Turn ignition switch to OFF position. Disconnect RCM connector. Measure resistance between chassis
ground and RCM connector terminal No. 21 (Black/Orange wire, circuit No. 649). See Fig. 14 . If
resistance is more than 100 ohms, repair open in Black/Orange wire. See WIRING DIAGRAMS . Go to
step 7 . If resistance is less than 100 ohms, replace RCM. Go to next step.

6. Check for intermittent fault

Refer to continuous DTCs recorded in step 1 . If DTC retrieved in step 1 was an intermittent fault, check
for cause of high resistance in Black/Orange wire (circuit No. 649). See WIRING DIAGRAMS .
Attempt to recreate fault by flexing wire harness and cycling ignition switch frequently. Repair any
intermittent problems found. Go to next step. If DTC retrieved in step 1 was not an intermittent fault. Go
to next step.

7. Check for additional DTCs

Refer to continuous DTCs recorded in step 1 . If any continuous DTCs were retrieved, go to diagnostic
trouble code identification table for direction to appropriate test. See DIAGNOSTIC TROUBLE CODE
(DTC) IDENTIFICATION table. DO NOT clear any DTCs until all DTCs have been resolved. If no
continuous DTCs were retrieved, reconnect air bag system. Reactivate air bag system. See
ACTIVATING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Clear all DTCs.
See CLEARING FAULT CODES under DIAGNOSTICS.

TEST S: PASSENGER AIR BAG CIRCUIT SHORT TO BATTERY OR IGNITION (DTC B1925)

Description

Restraints Control Module (RCM) checks passenger-side air bag module circuit for shorts to battery or ignition
voltage by monitoring voltage at RCM harness connector terminals No. 6 (Light Blue/Orange wire) and No. 7
(Pink/Black wire). If RCM detects short to battery or ignition voltage in either terminal, it will store Diagnostic
Trouble Code (DTC) B1925 in memory and flash Code 16 on AIR BAG warning light.

Possible Causes

NOTE:

Before proceeding, see AIR BAG SAFETY PRECAUTIONS .

2003 Ford Pickup F150

2003 ACCESSORIES/SAFETY EQUIPMENT Air Bag Restraint Systems - F150 Pickup