Section 13-11: Anti-Theft Alarm System
1994 Mustang Workshop Manual
DIAGNOSIS AND TESTING

Pinpoint Tests

  

PINPOINT TEST A: ALARM SYSTEM DOES NOT ARM OR DISARM PROPERLY

 

A1 RESET ALARM

Yes
System OK.

No
GO to A2.

 

A2 ALARM INDICATOR LAMP CHECK—LAMP OFF

Yes
GO to A3.

No
GO to A11.

 

A3 ALARM INDICATOR LAMP CHECK—LAMP BLINKING

  • Open a vehicle door .
  • Verify alarm indicator lamp blinks.
  • Does lamp blink?
Yes
GO to A4.

No
GO to A8 .

 

A4 ALARM INDICATOR LAMP VERIFICATION

  • Activate the electronic door lock control processor .
  • Verify the alarm indicator lamp glows continuously.
  • Does lamp glow continuously?
Yes
GO to A5.

No
GO to A9.

 

A5 ALARM INDICATOR LAMP TURNS OFF

  • Close the vehicle door completely.
  • Verify the alarm indicator lamp turns off after 30 seconds.
  • Does lamp turn off?
Yes
Manual arming sequence verified. GO to A12 .

No
REPLACE anti-theft alarm control . RETEST system. GO to A6 .

 

A6 ALARM INDICATOR LAMP OFF—ALARM TRIGGERS

  • Close the vehicle door completely.
  • Verify alarm indicator lamp turns off after 30 seconds.
  • Does lamp turn off and alarm trigger?
Yes
GO to Pinpoint Test I.

No
GO to A7 .

 

A7 PIN 14 VERIFICATION (DOOR AJAR INPUT)

  • Verify voltage on Pin 14 of the anti-theft alarm control is less than 2 volts with doors closed.
  • Is meter reading less than 2 volts with doors closed?
Yes
Damaged anti-theft alarm control . REPLACE. RETEST system.

No
Verify doors are completely closed. SERVICE door open warning lamp switches and/or CHECK short to B+ Circuit 24 (DB/O). Retest system.

 

A8 COURTESY LAMP OPERATION

  • Open vehicle doors.
  • Are the interior courtesy lamps on?
Yes
GO to A9 .

No
SERVICE door, courtesy lamp switches or Circuit 341 (O/W). RETEST system.

 

A9 PIN 14 VERIFICATION (DOOR AJAR INPUT)

  • Verify voltage on Pin 14 of anti-theft alarm control is greater than 7 volts with doors open.
  • Is voltage greater than 7 volts with doors open?
Yes
PERFORM Pinpoint Test G.

No
SERVICE door open warning lamp switch or Circuit 341 (O/W) or Circuit 24 (DB/O). RETEST system. GO to A10 .

 

A10 DOOR LOCK OPERATION

  • Lock door with lock portion of window regulator control switch .
  • Repeat with power door lock system.
  • Did the doors lock?
Yes
GO to A12.

No
REFER to door lock cylinder switch test or Section 01-14B. SERVICE as required. RETEST system.

 

A11 TERMINAL 7 AND 9 VERIFICATION (LOCK ALL DOORS INPUTS)

  • Verify door unlock terminal 7 (Circuit 118 PK/O) of the module is less than 2 volts and a momentary B+ signal is present at terminal 9 (Circuit 117 PK/BK) when the window regulator control switch or keyless entry unlock code is activated.
  • Is voltage greater than 2 volts and is momentary B+ signal present at terminal?
Yes
GO to A13 .

No
SERVICE Circuit 117 (PK/BK) or Circuit 118 (PK/O). (Note Circuit 117 (PK/BK) should be at B+ voltage level only momentarily when the lock switch is activated). RETEST system.

 

A12 ANTI-THEFT INDICATOR LAMP OPERATION

  • Disconnect the harness connectors from the anti-theft alarm control .
  • Does alarm indicator lamp stay on?
Yes
SERVICE Circuit 343 (DB/LG) for short to ground. RETEST system.

No
REPLACE anti-theft alarm control . RETEST system.

 

A13 TERMINAL 6 VERIFICATION

  • Verify voltage on terminal 6.
  • Is voltage greater than 2 volts?
Yes
REPLACE damaged anti-theft alarm control . RETEST system. GO to A14 .

No
SERVICE door disarm switches and/or short to ground in Circuit 25 (DG/P).

 

A14 ARM ANTI-THEFT SYSTEM WITH TRANSMITTER (OPTIONAL)

NOTE: Perform this step only for vehicles equipped with the Ford factory-installed remote keyless entry system. Otherwise, GO to A15.

  • Unlock driver door with key to disarm alarm.
  • Close all doors, doors should be unlocked.
  • Watch the alarm indicator lamp, located in the instrument cluster back plate , while performing this step.
  • Press the LOCK button on transmitter to lock doors.
  • Is lamp on?
Yes
All arming sequences verified. GO to A15 .

No
SERVICE remote keyless entry system as required. REFER to Section 01-14B.

 

A15 ELECTRIC DOOR UNLOCK CHECK  

  • Unlock and open door and activate electric lock switch.
  • Activate window regulator control switch .
  • Check result.
  • Is lamp blinking?
Yes
Arming sequence verified.

No
INSERT door key and unlock door to disarm system. GO to A16 .

 

A16 PINS 7 AND 9 VERIFICATION (UNLOCK DOORS INPUT)

  • Press unlock switch for the power door locks.
  • Verify a momentary B+ signal is at Pin 7 (Circuit 118 PK/O) and Pin 9 (Circuit 117 PK/BK) is less than 2 volts when unlock switch is activated.
  • Is B+ present momentarily on Pin 7 and Pin 9 is less than 2 volts during power unlock?
Yes
Damaged anti-theft alarm control. REPLACE RETEST system.

No
SERVICE Circuit 118 (PK/O) or Circuit 117 (PK/BK). RETEST system.

  

PINPOINT TEST B: ALARM SYSTEM DOES NOT ACTIVATE PROPERLY

 

B1 DOOR KEY DISARM CHECK

  • Arm the alarm system.
  • Insert door key into driver door and turn to the unlock position.
  • Open door. Check result.
  • Repeat Step
    B1
    for passenger door.
  • Does alarm trigger?
Yes
UNLOCK door using key in other door or keyless entry. UNLOCK or DISCONNECT battery to stop alarm. GO to B2.

No
System OK. GO to B3.

 

B2 PIN 6 VERIFICATION

  • Verify Pin 6 (Circuit 25 DG/P) of the anti-theft alarm control is less than 1 volt when the driver door key is in the unlocked position and the passenger door is locked.
  • Repeat Step
    B2
    , unlocking the passenger door with the driver door locked.
  • Is voltage less than 1 volt?
Yes
Damaged anti-theft alarm control . REPLACE, RETEST system.

No
SERVICE door lock cylinder switch or Circuit 25 (DG/P) for open circuit. RETEST system.

 

B3 REMOTE KEYLESS ENTRY DISARM CHECK (OPTIONAL)

NOTE: Perform this step only for vehicles equipped with the Ford factory-installed remote keyless entry system. Otherwise, go to Step B4.

  • Arm the alarm system.
  • Repeat Step
    B3
    unlocking the driver door by pressing the UNLOCK button of the remote entry transmitter.
  • Open a vehicle door. Check result.
  • Is warning lamp blinking?
Yes
Remote keyless entry disarm OK. GO to B4.

No
Disarm system by unlocking door with key. GO to B6.

 

B4 IGNITION KEY DISARM

  • Arm alarm system from inside vehicle.
  • Insert ignition key and turn ignition switch to ACC or RUN.
  • Open vehicle door.
  • Does alarm disarm?
Yes
Ignition input OK. System OK. STOP test.

No
GO to B5.

 

B5 PIN 4 VERIFICATION (RUN/ACC INPUT)

  • Verify Pin 4, Circuit 296 (W/P) of anti-theft alarm control is greater than 9 volts with ignition switch in RUN or ACC.
  • Are there 9 volts or more?
Yes
DAMAGED anti-theft alarm control . REPLACE. RETEST system.

No
SERVICE ignition switch or Circuit 296 (W/P) for open circuit. RETEST system.

 

B6 PIN 8 VERIFICATION

  • Verify a momentary B+ signal is present at Pin 8, Circuit 163 (R/O) when a remote entry transmitter unlock button is pressed.
  • Is there voltage present?
Yes
REPLACE damaged anti-theft alarm control . RETEST system.

No
SERVICE Circuit 163 (R/O). RETEST system. REFER to Section 01-14B for remote entry system.

  

PINPOINT TEST C: ALARM SYSTEM DOES NOT DISARM AFTER ACTIVATION

 

C1 VERIFY TRIGGERING

  • Arm the alarm system with a window down.
  • Open door by inside door handle.
  • Does the alarm trigger?
Yes
GO to C2.

No
GO to C8 .

 

C2 ALARM VERIFICATION—HORN

  • Does horn sound?
Yes
GO to C3.

No
GO to C10.

 

C3 ALARM VERIFICATION—TAIL/PARKING LAMP

  • Tail, parking lamp and alarm warning indicator lamp should flash.
  • Do tail and parking lamps flash?
Yes
GO to C4.

No
SERVICE Circuit 14 (BR). CHECK in-line fuse. RETEST system.

 

C4 ALARM VERIFICATION—ALARM WARNING INDICATOR

  • Does alarm warning indicator in dash panel flash?
Yes
GO to C5 .

No
SERVICE circuit 343 (DB/LG). RETEST system.

 

C5 ALARM VERIFICATION—LOW BEAM

  • Do low-beam headlamps flash?
Yes
GO to C6.

No
SERVICE Circuit 13 (R/BK). RETEST system.

 

C6 CHECK ALARM—STARTER RELAY

  • Does engine start?
Yes
REPLACE damaged anti-theft alarm control . RETEST system. GO to C7 .

No
System OK. STOP test. DISARM system.

 

C7 PIN 12 AND 24 VERIFICATION

  • Disconnect anti-theft alarm control from wiring harness.
  • Measure resistance between Pins 12 and 24 of the wiring harness connector.
  • Is the resistance less than 100 ohms?
Yes
SERVICE Circuits 32 (R/LB) and 33 (W/PK).

No
REPLACE damaged anti-theft alarm control. RETEST system. GO to C8 .

 

C8 LUGGAGE COMPARTMENT DOOR LOCK CYLINDER SWITCH VERIFICATION

  • Arm the alarm system.
  • Open the luggage compartment door .
  • Short contacts of luggage compartment door lock cylinder switch.
  • Verify system triggers.
  • Does alarm trigger?
Yes
System OK. STOP test. Unlock door with key to stop alarm.

No
GO to C9.

 

C9 PIN 5 VERIFICATION—LUGGAGE COMPARTMENT DOOR LOCK CYLINDER SWITCH INPUT

  • Measure the voltage at terminal 5 of control module, Circuit 23 (T/LG) while luggage compartment door lock cylinder switch is shorted.
  • Verify the voltage is less than 2 volts.
  • Is voltage less than 2 volts?
Yes
Anti-theft alarm control damaged. REPLACE. RETEST system.

No
SERVICE Circuit 23 (T/LG) and/or REPLACE luggage compartment door lock cylinder switch . RETEST system.

 

C10 HORN VERIFICATION

  • Activate horn from steering wheel .
  • Does horn sound?
Yes
GO to C11.

No
SERVICE Circuit 6 (Y/LG) or horn relay and bracket or horn . REFER to Section 13-06. RETEST.

 

C11 PIN 18 VERIFICATION

  • Verify voltage at Pin 18, Circuit 6 (Y/LG) is less than 2 volts.
  • Is voltage less than 2 volts?
Yes
SERVICE open in Circuit 6 (Y/LG). RETEST system.

No
REPLACE damaged anti-theft alarm control . RETEST system. GO to C12.

 

C12 DOOR KEY DISARM CHECK 

  • Arm the alarm system with a window down.
  • Open a door from the inside door handle.
  • Insert the door key into driver's door and turn to the unlock position.
  • Check result.
  • Repeat for passenger's door.
  • Does alarm trigger?
Yes
System OK. GO to C14.

No
GO to C13.

 

C13 PIN 6 VERIFICATION—DOOR DISARM INPUT

  • Verify Pin 6 of the anti-theft alarm control reads less than 1 volt with key in the unlock position.
  • Is voltage less than 1 volt?
Yes
REPLACE damaged anti-theft alarm control . RETEST system.

No
SERVICE door disarm switch or Circuit 25 (DG/P) for open. RETEST system.

 

C14 REMOTE KEYLESS ENTRY DISARM CHECK

NOTE: Perform this step only for vehicles equipped with remote keyless entry system.

  • Arm and trigger alarm as in Step D1.
  • Press the UNLOCK button of the remote keyless entry transmitter after triggering alarm.
  • Check result.
  • Does alarm turn off?
Yes
System OK. GO to C16.

No
GO to C15.

 

C15 PIN 8 VERIFICATION—UNLOCK DRIVER DOOR INPUT

  • Verify a momentary B+ signal is present at Pin 8, Circuit 163 (R/O) when the door lock switch actuator unlock code or unlock button of the remote entry transmitter has been used.
  • Is voltage less than 1 volt?
Yes
SERVICE Circuit 163 (R/O). RETEST system.

No
REPLACE damaged anti-theft alarm control . RETEST system.

 

C16 ALARM RESET CHECK

  • Arm the alarm system with a window down.
  • Open the door from the inside door handle.
  • Wait three minutes.
  • Does alarm reset?
Yes
System OK. STOP. DISARM system.

No
REPLACE damaged anti-theft alarm control . RETEST system.

  

PINPOINT TEST D: ENGINE WILL NOT CRANK

 

D1 ENSURE ALARM SYSTEM IS RESET 

  • Insert door key and turn to the unlock position.
  • Open vehicle door.
  • Does system trigger?
Yes
GO to C12.

No
GO to D2 .

 

D2 CHECK BATTERY VOLTAGE

  • Measure battery voltage.
  • Verify voltage is greater than 9 volts.
  • Is voltage greater than 9 volts?
Yes
GO to D3.

No
SERVICE battery . REFER to Section 14-00. RETEST system.

 

D3 CHECK RESISTANCE OF STARTER INTERRUPT CIRCUIT

  • Measure resistance between terminals 12 and 24 of the anti-theft alarm control .
  • Is resistance greater than 100 ohms?
Yes
REPLACE damaged anti-theft alarm control . RETEST system.

No
System OK. SERVICE starting system. Refer to Section 03-06.

  

PINPOINT TEST E: ALARM INDICATOR IS ON ALL THE TIME

 

E1 ENSURE ALARM SYSTEM IS RESET 

  • Arm the anti-theft alarm system.
  • Within 30 seconds, insert door key and turn to unlock position.
  • Does lamp turn off?
Yes
System OK.

No
GO to E2.

 

E2 CHECK FOR SHORT

  • Disconnect anti-theft alarm control connectors.
  • Does lamp turn off?
Yes
REPLACE damaged anti-theft alarm control . RETEST system.

No
SERVICE Circuit 343 (DB/LG) for short circuit. RETEST system.

  

PINPOINT TEST F: ALARM INDICATOR DOES NOT TURN ON TO INDICATE ARMING

 

F1 CHECK LAMP AND CIRCUIT 343 (DB/LG) 

  • With a jumper wire, short terminal 15 Circuit 343 (DB/LG) of the anti-theft alarm control to ground.
  • Does alarm indicator lamp turn on?
Yes
GO to F2.

No
SERVICE alarm indicator lamp, Circuit 343 (DB/LG) or 54 (LG/Y) for open circuit. RETEST system.

 

F2 CHECK MODULE BATTERY INPUT

  • Measure terminal 1 Circuit 196 (DB/O) of the anti-theft alarm control for greater than 9 volts.
  • Is voltage greater than 9 volts?
Yes
GO to F3.

No
SERVICE fuse and/or Circuit 196 (DB/O). RETEST system.

 

F3 CHECK IGNITION INPUT

  • Measure Pin 4, Circuit 296 (W/P) of the anti-theft alarm control for less than 9 volts.
  • Is voltage less than 9 volts?
Yes
GO to F4.

No
SERVICE Circuit 296 (W/P) for short to B+. RETEST.

 

F4 CHECK ANTI-THEFT ALARM CONTROL OPERATION

  • Open a vehicle door.
  • Activate the power door lock switch.
  • Does lamp blink then glow steadily?
Yes
System OK.

No
REPLACE damaged anti-theft alarm control . RETEST system.

  

PINPOINT TEST G: HORN, HEADLAMPS AND/OR EXTERIOR LAMPS ALWAYS ON

 

G1 HORN ALWAYS ON

  • Disconnect anti-theft alarm control .
  • Does horn turn off?
Yes
REPLACE damaged anti-theft alarm control . RETEST system.

No
SERVICE horn system. REFER to Section 13-06. RETEST system. GO to G2.

 

G2 LOW BEAM HEADLAMPS ALWAYS ON

  • Disconnect anti-theft alarm control.
  • Do headlamps turn off?
Yes
REPLACE damaged anti-theft alarm control . RETEST system.

No
SERVICE Circuit 13 (R/BK). RETEST system. GO to G3.

 

G3 TAIL LAMPS/PARKING LAMPS ALWAYS ON

  • Disconnect anti-theft alarm control .
  • Do parking lamps turn off?
Yes
REPLACE damaged anti-theft alarm control . RETEST system.

No
SERVICE Circuit 14 (BR). RETEST system.

  

PINPOINT TEST H: SYSTEM ACTIVATES FALSELY

 

H1 ALARM SYSTEM

  • Arm the alarm system.
  • Verify system does not trigger immediately after system is armed. (System arms after 30 seconds when the alarm indicator lamp goes from solid to off).
  • Does system trigger?
Yes
DISARM system by unlocking driver or passenger door with key. GO to I3.

No
GO to H2.

 

H2 LUGGAGE COMPARTMENT DOOR LOCK CYLINDER SWITCH CHECK

  • While system remains armed, open luggage compartment and apply movement to the luggage compartment door lock cylinder switch connector and cable.
  • Verify system does not trigger.
  • Does system trigger?
Yes
DISARM system. REPLACE luggage compartment door lock cylinder and matching glove compartment cylinder. RETEST system.

No
GO to H3.

 

H3 DOOR AJAR CHECK

  • Measure voltage at Pin 3 with all doors closed.
  • Is voltage greater than 2 volts?
Yes
GO to H4.

No
SERVICE Circuit 627 (BK/O) or door ajar switches.

 

H4 CHECK VOLTAGE AT CIRCUIT 23 (T/LG)

  • Measure voltage at Pin 5.
  • Is voltage greater than 2 volts?
Yes
GO to H6.

No
GO to H5.

 

H5 LUGGAGE COMPARTMENT DOOR LOCK CYLINDER SWITCH CHECK

  • Disconnect luggage compartment door lock cylinder switch from wiring harness.
  • Measure voltage at Pin 5 of anti-theft module harness connector.
  • Is voltage greater than 2 volts?
Yes
REPLACE luggage compartment door lock cylinder and matching glove compartment cylinder. REFER to Section 01-14A. RETEST system.

No
SERVICE Circuit 23 (T/LG).

 

H6 REMOTE ENTRY PANIC CHECK

NOTE: Perform this step only for vehicles equipped with the Remote Keyless Entry System.

  • When the alarm triggers falsely, turn ignition switch to RUN/ACC position.
  • Does alarm continue to sound?
Yes
REPLACE damaged anti-theft alarm control . RETEST system.

No
REFER to Section 01-14B for the PANIC Alarm Diagnosis.

  

PINPOINT TEST I: IGNITION KEY LOCK CYLINDER SENSOR

 

I1 ALARM SYSTEM—DISARM 

  • Disconnect battery ground cable.
  • Wait 10 seconds.
  • Reconnect battery ground cable.
  • Does alarm trigger?
Yes
GO to I4.

No
GO to I2.

 

I2 IGNITION KEY LOCK CYLINDER SENSOR OPERATION

  • With ignition switch OFF, disconnect the ignition key lock cylinder sensor from the wiring harness.
  • Does alarm trigger?
Yes
System OK. RECONNECT sensor and STOP.

No
GO to I3.

 

I3 PINS 23 AND 26 VERIFICATION 

  • Verify continuity between Pin 23 and Pin 26 at the anti-theft alarm control module.
  • Is there continuity?
Yes
GO to I4.

No
SERVICE Circuit 397 (BK/W). RETEST system.

 

I4 ANTI-THEFT MODULE RESISTANCE

  • Disconnect anti-theft alarm control module and measure resistance between Pin 10 and Pin 26.
  • Is resistance between 145 and 175 ohms?
Yes
REPLACE control module. RETEST system.

No
SERVICE Circuit 936 (DG/W) and/or REPLACE ignition key lock cylinder sensor. RETEST system.

For Vehicles Equipped with the Ford Factory Installed Remote/Keyless Entry System:

NOTE: The Ford factory-installed Remote/Keyless Entry System has a PANIC feature that honks the vehicle horns and flashes the exterior lamps when the PANIC button on the remote entry transmitter is pushed. The Electronic Door Lock Control Processor and the Anti-Theft Alarm Control are two separate modules. If the remote entry PANIC button is unintentionally pushed, the honking horns and flashing exterior lamps may be mistaken for the Anti-Theft Alarm System falsely triggering.

When a PANIC alarm is activated, the alarm indicator light will not blink. The only way to deactivate the PANIC alarm is to hit the PANIC button again or turn the ignition switch to RUN or ACC position.

If the vehicle has a Ford Remote/Keyless Entry System but does not have an Anti-Theft Alarm System, refer to Section 01-14B for Panic Alarm Diagnosis.

  

PINPOINT TEST J: DIAGNOSTICS FOR IGNITION LOCK TAMPER CYLINDER SWITCH, DOOR LOCK CYLINDER SWITCH AND LUGGAGE COMPARTMENT CYLINDER INPUTS

 

J1 IGNITION LOCK CYLINDER SWITCH OPERATION 

  • Turn ignition switch to RUN.
  • Observe anti-theft alarm indicator.
  • Does indicator remain on for 10 seconds?
Yes
Ignition key lock cylinder sensor OK. GO to J2.

No
Ignition key lock cylinder sensor input shorted. GO to I1.

 

J2 DOOR LOCK CYLINDER SWITCH

NOTE: This diagnostic mode quickly provides the capability to identify a shorted to ground condition for the door lock cylinder switch and/or luggage compartment tamper circuit.

  • Turn ignition switch to RUN.
  • Activate power door unlock button 5 times in 10 seconds.
  • Observe anti-theft indicator lamp, count flashes (repeats every 10 seconds).

    NOTE: Diagnostic mode will automatically cancel after two minutes or by turning ignition switch from RUN to OFF.

  • Does indicator lamp flash once?
Yes
Door lock cylinder switch and luggage compartment inputs normal.

No
Door lock cylinder switch input shorted. SERVICE door lock cylinder switches or Circuit 25 (DG/P). GO to J3.

 

J3 DOOR LOCK CYLINDER SWITCH —(SHORTED TO GROUND)

  • Turn ignition switch to RUN.
  • Activate power door unlock button 5 times in 10 seconds.
  • Observe anti-theft indicator lamp, count flashes (repeats every 10 seconds).

    NOTE: Diagnostic mode will automatically cancel after two minutes or by turning ignition switch from RUN to OFF.

  • Does indicator lamp flash three times?
Yes
Luggage compartment door lock cylinder switch input shorted. SERVICE luggage compartment door lock cylinder switch or Circuit 486 (BR/W).

No
Both inputs shorted. SERVICE door lock cylinder switches or Circuit 25 (DG/P). SERVICE luggage compartment door lock cylinder switch or Circuit 486 (BR/W).