Mazda RX-7 Anti-Theft System: operations, diagnostics and more

Mazda RX7 1993-1995 FD3S



If alarm is activated, headlights and hazard lights flash, horn sounds and starter is disabled. Alarm will activate if the hood, rear hatch or a door is opened without a key, or if ignition switch is forced into START position without a key. Central Processing Unit No. 2 (CPU No. 2) controls the system based on inputs it receives from the following switches:

• Door switches indicate whether a door is open or closed.
• Key cylinder switches indicate whether or not door key cylinder or the rear hatch key cylinder is turned to the unlocked position.
• Door lock link switches indicate whether a door is locked or unlocked.
• Hood switch indicates whether the hood is open or closed.
• Cargo compartment light switch indicates whether the rear hatch is open or closed.

ELECTRICAL COMPONENT LOCATIONS

• Cargo Compartment Light Switch: On Rear Hatch Latch
• CPU No. 2: Behind Left Kick Panel, (Part Of Joint Box)
• Flasher Unit: Integral Part Of CPU No. 2
• Headlight Relay: On Left Front Inner Fender
• Hood Switch: On Hood Latch
• Horn Relay: In Relay Block Above Radiator
• Starter Cut Relay: Behind Left Kick Panel, On Joint Box

CIRCUIT TESTING

CPU NO. 2 CONNECTOR PIN VOLTAGES AND CONTINUITY

• 8-Pin Connector
  • 2B (Horn Relay)
    • Alarm Sounds: No Voltage
    • Horn Switch On: No Voltage
    • Other: Battery Voltage
  • 2D (Starter Cut Relay)
    • Ignition Off: No Voltage
    • Ignition On: Battery Voltage
• 20-Pin Connector
  • 1B (Ign. Key Reminder Switch)
    • Key Inserted: Battery Voltage
    • Key Removed: No Voltage
  • 1E (Door Switch)
    • Door Closed: No Continuity
    • Door Open: Continuity
  • 1F (Cargo Comp. Light Switch)
    • Rear Hatch Closed: No Continuity
    • Rear Hatch Open: Continuity
  • 1G (Hood Switch)
    • Hood Closed: No Continuity
    • Hood Open: Continuity
  • 1I (Passenger Door Lock Switch)
    • Locked: Approx. 5 Volts
    • Unlocked: No Voltage
  • 1J (Driver Door Lock Switch)
    • Locked: Battery Voltage
    • Unlocked: No Voltage
  • 1N (Door Key Cylinder Switch)
    • Locked: 5 Volts
    • Unlocked (Hold key cylinder in unlocked position): No Voltage
  • 1O (Rear Hatch Key Cylinder Switch)
    • Locked No Continuity
    • Unlocked (Hold key cylinder in unlocked position): Continuity
  • 1V (Hazard Switch)
    • Hazard Switch Off: Battery Voltage
    • Hazard Switch On: No Voltage

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COMPONENT TESTING

DOOR SWITCH

Remove door switch. Check continuity between switch connector terminal and switch body. With door switch button pressed (door closed), continuity should not exist. With door switch button released (door open), continuity should exist. If continuity is not as specified, replace door switch.

DOOR KEY CYLINDER SWITCH

Remove door trim panel. Disconnect door key cylinder switch connector. Check continuity between Light Green/Black and Black wire terminals of door key cylinder switch connector. With door key cylinder turned to unlocked position, continuity should exist. With door key cylinder in any other position, continuity should not exist. If continuity is not as specified, replace door lock cylinder.

DOOR LOCK LINK SWITCH (DRIVER DOOR)

There is no door lock link switch for driver door. To determine if door is locked or unlocked, CPU receives input from power door lock switch (indirectly, via the door lock timer unit). To check power door lock switch and door lock timer unit.

DOOR LOCK LINK SWITCH (PASSENGER DOOR)

Door lock link switch is inside power door lock actuator. Remove door trim panel. Disconnect door lock actuator 4-pin connector. Check continuity between terminals "C" (Green/Black wire) and "D" (Black wire) of door lock actuator connector. With door locked, continuity should not exist. With door unlocked, continuity should exist. If continuity is not as specified, replace door lock actuator.

FLASHER UNIT

If turn signal and/or hazard flasher operation is incorrect, check for faults in circuits leading to flasher unit. See Fig. 1. If no faults are found, replace flasher unit.

Fig. 1: Flasher Unit Circuit Diagram/Connector Terminals

HORN RELAY

Remove horn relay. Check continuity between horn relay terminals "A" and "C". See Fig. 2 . If continuity exists, replace horn relay. If continuity does not exist, apply battery voltage across horn relay terminals "B" and "D". Check continuity between horn relay terminals "A" and "C". If continuity exists, horn relay is okay. If continuity does not exist, replace horn relay.

Fig. 2: Identifying Horn Relay Terminals

HEADLIGHT RELAY

Remove headlight relay. Check continuity between headlight relay terminals "C" and "D". See Fig. 3. If continuity exists, replace headlight relay. If continuity does not exist, apply battery voltage across headlight relay terminals "A" and "B". Check continuity between headlight relay terminals "C" and "D". If continuity exists, headlight relay is okay. If continuity does not exist, replace headlight relay.

Fig. 3: Identifying Headlight Relay Terminals

STARTER CUT RELAY

Remove starter cut relay. Check continuity between starter cut relay terminals "C" and "F". See Fig. 4 . If continuity exists, replace starter cut relay. If continuity does not exist, apply battery voltage across starter cut relay terminals "A" and "B". Check continuity between starter cut relay terminals "C" and "F". If continuity exists, starter cut relay is okay. If continuity does not exist, replace starter cut relay.

Fig. 4: Identifying Starter Cut Relay Terminals

REAR HATCH KEY CYLINDER SWITCH

Remove trim panel on rear hatch to access rear hatch key cylinder switch. Disconnect rear hatch key cylinder switch connector. Check continuity between rear hatch trim panel switch connector terminals. With rear hatch key cylinder turned to unlocked position, continuity should exist. With rear hatch key cylinder in any other position, continuity should not exist. If continuity is not as specified, replace rear hatch key cylinder switch.

CARGO COMPARTMENT LIGHT SWITCH

Cargo compartment light switch is inside rear hatch latch assembly. Disconnect cargo compartment light switch connector (if necessary, remove trim panel and rear hatch latch for access). Check continuity between cargo compartment light switch connector terminals. With switch button pushed (rear hatch closed), continuity should not exist. With switch button released (rear hatch open), continuity should exist. If continuity is not as specified, replace cargo compartment light switch.

HOOD SWITCH

Disconnect hood switch connector near hood latch. Check continuity between hood switch connector terminals. With switch lever released (hood open), continuity should exist. With switch lever pushed (hood closed), continuity should not exist. If continuity is not as specified, replace hood switch.

KEY REMINDER SWITCH

Remove steering column cover. Disconnect key reminder switch connector. Check continuity between terminals "A" (Blue/Red wire) and "B" (White wire) of key reminder switch connector. With ignition key inserted, continuity should exist. With ignition key removed, continuity should not exist. If continuity is not as specified, replace key reminder switch.

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SYSTEM TESTING

SYSTEM OPERATION

Initial Phase
Remove ignition key.

Pre-Arming Phase 1
With hood and rear hatch closed, open any door. Security light will illuminate and buzzer sounds once.

Pre-Arming Phase 2
Lock and close all doors. After security light stays lit for 10 seconds, system proceeds to arming phase 1. Buzzer sounds once.

Arming Phase 1
Security light flashes every 3 seconds, and system is armed.

Arming Phase 2
Rear hatch may be opened with key during arming phase 1. Security light should continue to flash. Process returns to arming phase 1 after rear hatch is closed.

Alarm Phase 1
If a door, hood or rear hatch is opened without a key, or if ignition switch is forced to the ON position, alarm is activated (horn sounds intermittently, headlights and hazard lights flash for 3 minutes, and starter does not operate).

Alarm Phase 2
Horn stops sounding, headlights and hazard lights stop flashing, but starter remains inoperative.

Alarm Stop Phase
Unlock any door or rear hatch with key.

If system does not operate as previously described, use the following procedure to determine where to begin testing.



1. Open any door window. Close both doors. Remove ignition key. With hood and rear hatch closed, open either door. If security light illuminates and buzzer sounds once, go to next step. If security light does not illuminate and buzzer does not sound, go to TEST NO. 1. If security light does not illuminate but buzzer sounds, go to TEST NO. 2. If security light illuminates but buzzer does not sound, go to TEST NO. 3.
2. Turn ignition on. If security light does not go out, go to TEST NO. 4. If security light goes out, go to next step.
3. Perform step 1) to set arming condition. Close and lock all doors. Wait 10 seconds. Unlock either door lock knob. Security light should go out, horn should sound, and headlights and hazard lights should flash. Starter should not operate when trying to start engine. If results are as specified, go to next step. If results are not as specified, go to appropriate test.

• If security light does not go out, go to TEST NO. 4.
• If horn does not sound, go to TEST NO. 5.
• If headlights do not flash, go to TEST NO. 6.
• If hazard lights do not flash, go to TEST NO. 7.
• If starter operates, go to TEST NO. 8.

4. Using key, unlock driver or passenger door key cylinder or open rear hatch. Warning should cancel (horn should stop sounding, headlights and hazard lights should stop flashing and starter should operate).

• If warning cancels when door and rear hatch key cylinders are unlocked, go to next step.
• If warning does not cancel when door key cylinder is unlocked, go to TEST NO. 9.
• If warning does not cancel when rear hatch key cylinder is unlocked, go to TEST NO. 10.

5. Remove STOP and HEAD fuses. Perform steps 1), 2) and 3). If hazard lights do not flash for 3 minutes, or do not stop flashing after about 3 minutes, go to TEST NO. 11.

SYSTEM DIAGNOSTIC

Before performing the following tests, perform SYSTEM OPERATION TEST to determine which test to follow.

Test No. 1
1. Check ROOM fuse. If fuse is faulty, replace ROOM fuse (repair circuit if shorted). If fuse is okay, go to next step.
2. Measure voltage at terminal 1A (Blue/Red wire) of CPU No. 2 20-pin connector. See Fig. 5 . If battery voltage is not present, repair wiring between ROOM fuse and CPU No. 2. If battery voltage is present, go to next step.
3. Disconnect CPU No. 2 20-pin connector. Check continuity between ground and terminal 1H (Black wire) of CPU No. 2 20-pin connector. If continuity does not exist, repair wiring between CPU No. 2 and ground. If continuity exists, reconnect CPU No. 2 connector and go to next step.
4. Remove side panel and lower panel. Measure voltage at terminal "A" (Blue/Red wire) of key reminder switch 4-pin connector. If battery voltage is present, go to next step. If battery voltage is not present, repair wiring harness between ROOM fuse and key reminder switch.
5. Disconnect key reminder switch 4-pin connector. With ignition key inserted, check continuity between terminals "A" (Blue/Red wire) and "D" (White wire) of key reminder switch. If continuity exists, reconnect key reminder switch connector and go to next step. If continuity does not exist, replace steering lock assembly.
6. With ignition key inserted, measure voltage at terminal 1B (White wire) of CPU No. 2 20-pin connector. If battery voltage is present, go to next step. If battery voltage is not present, repair wiring between key reminder switch and CPU No. 2.
7. Disconnect CPU No. 2 20-pin connector. Close passenger door. Open driver door and check continuity between ground and terminal 1E (Blue/White wire) of CPU No. 2 20-pin connector. If continuity does not exist, go to next step. If continuity exists, go to step 9).
8. Remove driver door switch. Check continuity between driver door switch terminal and switch body with switch button released. If continuity exists, repair wiring between CPU No. 2 and driver door switch. If continuity does not exist, replace driver door switch.
9. Close driver door. Open passenger door. Check continuity between ground and terminal 1E (Blue/White wire) of CPU No. 2 20-pin connector. If continuity exists, go to next step. If continuity does not exist, go to step 11).
10. Remove passenger door switch. Check continuity between passenger door switch terminal and switch body with switch button released. If continuity exists, repair wiring between CPU No. 2 and passenger door switch. If continuity does not exist, replace passenger door switch.
11. With hood and rear hatch open, check continuity between ground and terminal 1F (Gray wire) of CPU No. 2 20-pin connector. If continuity does not exist, go to next step. If continuity exists, check continuity between ground and terminal 1G (Brown/Yellow wire) of CPU No. 2 20-pin connector. If continuity exists, go to step 14). If continuity does not exist, go to step 13).
12. Remove rear hatch trim panel. Disconnect cargo compartment light switch connector. Check continuity between cargo compartment light switch connector terminals. With switch button pushed (rear hatch closed), continuity should not exist. With switch button released (rear hatch open), continuity should exist. If continuity is not as specified, replace cargo compartment light switch. If continuity is as specified, repair wiring between CPU No. 2 and cargo compartment light switch.
13. Disconnect hood switch connector. Check continuity between hood switch connector terminals. With switch lever pushed (hood closed), continuity should not exist. With switch lever released (hood open), continuity should exist. If continuity is not as specified, replace hood latch assembly. If continuity is as specified, repair wiring between CPU No. 2 and hood switch.
14. Remove center console. Remove security light. Measure voltage at terminal "A" (Blue/Red wire) of security light 3-pin connector. If battery voltage is not present, repair wiring between ROOM fuse and security light. If battery voltage is present, go to next step.
15. Check continuity between terminals "A" (Blue/Red wire) and "B" (Violet/Green wire) of security light connector. If continuity does not exist, replace security light. If continuity exists, go to next step.
16. Check continuity between terminal "B" (Violet/Green wire) of security light connector and terminal 1R (Violet/Green wire) of CPU No. 2 20-pin connector. If continuity does not exist, repair wiring between security light and CPU No. 2. If continuity exists, replace CPU No. 2.

Fig. 5: Identifying CPU No. 2 Connector Terminals (20-Pin)

Test No. 2
1. Remove center console. Remove security light. Measure voltage at terminal "A" (Blue/Red wire) of security light 3-pin connector. If battery voltage is not present, repair wiring between ROOM fuse and security light. If battery voltage is present, check continuity between terminals "A" (Blue/Red wire) and "B" (Violet/Green wire) of security light connector.
2. If continuity does not exist, replace security light. If continuity exists, disconnect CPU No. 2 20-pin connector. Check continuity between terminal "B" (Violet/Green wire) of security light connector and terminal 1R (Violet/Green wire) of CPU No. 2 connector. See Fig. 5. If continuity does not exist, repair wiring between security light and CPU No. 2. If continuity exists, replace CPU No. 2.

Test No. 3 and 4
Replace CPU No. 2.

Test No. 5
Press horn pad. If horn does not sound, repair horn circuit. If horn sounds, with horn off, measure voltage at terminal 2B (Green/Orange wire) of CPU No. 2 8-pin connector. SeeFig. 6 . If battery voltage is not present, repair wiring between horn relay and CPU No. 2. If battery voltage is present, replace CPU No. 2.

Test No. 6
Turn on headlights. If headlights do not illuminate, repair headlight circuit. If headlights illuminate, turn off headlights. Measure voltage at terminal 2H (White/Blue wire) of CPU No. 2 8-pin connector. See Fig. 6. If battery voltage is not present, repair wiring between headlight relay and CPU No. 2. If battery voltage is present, replace CPU No. 2.

Fig. 6: Identifying CPU No. 2 Connector Terminals (8-Pin)

Test No. 7
Turn on hazard lights. If hazard lights do not illuminate, repair hazard lights circuit. If hazard lights illuminate, turn off hazard lights. Measure voltage at terminal 1V (Orange wire) of CPU No. 2 20-pin connector. See Fig. 5. If battery voltage is not present, repair wiring between flasher unit and CPU No. 2. If battery voltage is present, replace CPU No. 2.

Test No. 8
1. Check ENGINE fuse. If fuse is faulty, replace ENGINE fuse (repair circuit if shorted). If fuse is okay, remove driver front side trim panel. Turn ignition on. Measure voltage at terminal "A" (Black/Light Green wire) of starter cut relay 6-pin connector. See Fig. 4. If battery voltage is not present, repair wiring between ENGINE fuse and starter cut relay.
2. If battery voltage is present, turn ignition off. Disconnect starter cut relay 6-pin connector. Check continuity between terminals "C" and "F" of starter cut relay. If continuity exists, replace starter cut relay. If continuity does not exist, apply battery voltage across terminals "A" and "B" of starter cut relay. Check continuity between terminals "C" and "F" of starter cut relay.
3. If continuity does not exist, replace starter cut relay. If continuity exists, turn ignition on. Measure voltage at terminal 2D (Light Green/Red wire) of CPU No. 2 8-pin connector. If battery voltage is not present, repair wiring between starter cut relay and CPU No. 2. If battery voltage is present, replace CPU No. 2.

Test No. 9
1. Disconnect CPU No. 2 20-pin connector. See Fig. 5. Lock both door locks. Check continuity between ground and terminal 1N (Light Green/Black wire) of CPU No. 2 20-pin connector. If continuity exists, replace CPU No. 2. If continuity does not exist, remove trim panel from door of suspect switch. Go to next step for driver-side door. Go to step 4) for passenger-side door.
2. On driver-side, disconnect door key cylinder switch 4-pin connector. Check continuity between ground and terminal "D" (Black wire) of driver door key cylinder switch connector. If continuity does not exist, repair wiring between driver door key cylinder switch and ground.
3. If continuity exists, with driver door key cylinder turned to unlocked position, check continuity between terminals "B" (Light Green/Black wire) and "D" (Black wire) of driver door key cylinder switch connector. If continuity does not exist, replace driver door lock cylinder. If continuity exists, repair wiring between driver door key cylinder switch and CPU No. 2.
4. On passenger-side, disconnect door key cylinder switch 2-pin connector. Check continuity between ground and terminal "B" (Black wire) of passenger door key cylinder switch connector. If continuity does not exist, repair wiring between passenger door key cylinder switch and ground.
5. If continuity exists, with passenger door key cylinder turned to unlocked position, check continuity between terminals "A" (Light Green/Black wire) and "B" (Black wire) of passenger door key cylinder switch connector. If continuity does not exist, replace passenger door lock cylinder. If continuity exists, repair wiring between passenger door key cylinder switch and CPU No. 2.

Test No. 10
1. Disconnect CPU No. 2 20-pin connector. See Fig. 5. With rear hatch key cylinder turned to unlocked position, check continuity between ground and terminal 1O (Light Green/Red wire) of CPU No. 2 20-pin connector. If continuity exists, replace CPU No. 2.
2. If continuity does not exist, remove rear hatch trim panel. Disconnect rear hatch key cylinder switch 3-pin connector. With rear hatch key cylinder turned to unlocked position, check continuity between terminals "A" (Light Green/Red wire) and "C" (Black wire) of rear hatch key cylinder switch connector.
3. If continuity does not exist, replace rear hatch lock assembly. If continuity exists, check continuity between ground and terminal "C" (Black wire) of rear hatch key cylinder switch connector. If continuity does not exist, repair wiring between rear hatch key cylinder switch and ground. If continuity exists, repair wiring between CPU No. 2 and rear hatch key cylinder switch.

Test No. 11
Replace CPU No. 2.



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Mazda RX7 1993-1995 FD3S

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