service MAZDA MX-5 1994 Repair Manual

T OUTLINE OUTLINE TROUBLESHOOTING GUIDE Symptom a Speedometer does not operate or indication is incorrect a Tachometer does not operate Water temperature gauge does not operate Fuel gauge does not operate a Oil pressure gauge does not operate a Brake system warning light remains illuminated Brake system warning light does not illuminate when parking brake on a Brake system warning light does not illuminate when brake fluid in reservoir is below MIN a OID off indicator light does not illuminate when OID off switch turned on Seat belt warning light remains on six seconds after ignition switch is turned on (Timer function does not operate) Seat belt warning light does not illuminate when ignition switch is first turned on a Headlights do not illuminate Headlight does not illuminate (Right or left) Retractable headlight actuator do not operate (Both sides) Retractable headlight actuator does not operate (One side) Stoplights do not illuminate (All) Stoplight does not illuminate (One only) Turn and hazard warning functions do not operate Turn signals not operate (Hazard warning function operates normally) Hazard warning function does not operate (Turn signals function normally) Back-up lights does not illuminate Taillights, side marker lights, and license plate lights do not illuminate Daytime running lights do not illuminate Daytime running light function does not cancel lnterior lights do not illuminate Interior liahts remains illuminated (Control switch: DOOR ~osition) Horn does not sound Vehicle speed cannot be set (Cruise control unit will not hold vehicle speed) Speakers do not operate (Without headrest speakers) Speakers do not operate (With headrest speakers) Poor sound quality or noise (Radio) Poor sound quality (Cassette tape player) Cassette tape will not load Cassette tape will not play Compact disc will not load Compact disc skips No sound can be heard Some speakers do not operate Bodysonic will not play Service code table (With passenger-side air bag) Service code table (With out ~assenaer-side air baa) Reference page T-24 T-25 T-26 T-27 T-28 T-36 T-37 T-37 Gartner Banana

T FUSE DESCRIPTION Main Fuse Block The main fuse block is located on the right side of the engine compartment and contains nine fuses and two relays. -1 Fuse Box Fuse block No.1 is located above the dead pedal of the driver side. The fuse box cover shows the speci- fied fuse locations. A circuit breaker is included in the fuse box to protect the heater blower motor circuit. Fuse block No.2 is located to the side of the battery in the trunk compartment. 45UOTX-016 REPLACEMENT Caution Determine and correct the cause of a burnt fuse before replacing it. If the fuse is replaced before doing this, it may burn again. Plate type 1. Disconnect the negative battery cable. 2. Replace the failed fuse with the fuse puller. 3. Reconnect the negative battery cable. Cartridge-type 80A fuse (Black) 1. Disconnect the negative battery cable. 2. Remove the fuse block mounting nuts, and remove the service cover. 3. Remove the fuse installation bolts, and pull out the fuse. 4. Install the new fuse and the fuse installation bolts. 5. Install the main fuse block. 6. Reconnect the negative battery cable. Gartner Banana

CRUISE CONTROL SYSTEM T Inspection Procedure Self-diagnosis 1. Connect a 1.4W test light between terminals D and F, of the cruise control unit connector. Note There is no wire in terminal D of the connector. Push the test light through the connector and touch the cor- responding pin on the control unit. 2. Turn the ignition switch to ON. 3. Turn the cruise control on by pressing the MAlN switch. The MAlN indicator light will come on. 4. Press and hold the RESUMEIACCEL switch for more than 3 seconds. The test light will illuminate for 3 se- conds and go out for 2 seconds. 5. The on-board diagnosis system is activated and the test light will flash if there is a problem. Refer to the chart be- low to obtain the problem code number. Note The cruise control system will not operate in self-diag- nosis mode. 6. After retrieving the code(s), drive the vehicle at more than 16 kmlh (10 MPH) or press the MAlN switch to deactivate self-diagnosis. The MAlN indicator light will go off. 7. Follow the action corresponding to the problem code. Service Code Table If there are two or more problems in the system, the problem with the highest priority will be indicated. Priority Pattern of output signal ON 2 OFF n 4 OFF ON 5 OFF I No. Code I Possible cause Defective wiring (Cruise actuator- Cruise control unit, Stoplight switch-Cruise control unit) 01 Defective actuator Defective stoplight switch (For O5 1 Defective wiring (Fuse - Cruise control unit) Both stoplight and brake switch (for 07 vehicle and cruise) are ON simulta- neously Defective SETICOAST, or RESUMEIACCEL switch l5 1 Defective cruise control unit Action Repair harness lnspect actuator (Refer to page T-107) Inspect brake switch (Refer to page T-105) Replace fuse Repair harness Inspect stoplight and brake switch (Refer to pages T-105 and T-56) Inspect cruise control switch (Refer to page T-106) Go to troubleshooting Gartner Banana

T 2 CRUISE CONTROL SYSTEM PRESS 45UOTX-209 Inspection Procedure Quick inspection 1. Connect a 1.4W test light between terminals D and F, of the cruise control unit connector. u Note There is no wire in terminal D of the connector. Push the test light through the connector and touch the cor- responding pin on the control unit. 2. Turn the ignition switch to ON. 3. Shift the selector lever to D or R range. 4. Verify that the MAlN switch is off. (The MAlN indicator light will be off .) 5. Turn the RESUMEIACCEL switch and the MAlN switch simultaneously to activate the system inspection. The MAlN indicator light will come on. 6. Operate each switch as described below and obtain the problem code numbers. Note The cruise control system will not operate in self-diag- nosis mode. 7. After retrieving the code(s), press the MAlN switch to deactivate the system inspection. The MAlN indicator light will go off. 8. Follow the action corresponding to the problem code. --, Service Code Table Press SETICOAST switch Procedure Press RESUMEIACCEL switch Pattern of output signal (Test light) ON OFF nn M nn Depress brake pedal ON OFF ON Drive vehicle above 40 km/h (25 MPH) Turn ignition switch to ON and shift the selector lever to P or N range (For AT) Depress clutch pedal (For MT) Code No. oN OFF Action lnspect cruise control switch (Refer to page T-106) lnspect cruise control switch (Refer to page T-106) lnspect stoplight switches (Refer to pages T-105 and T-56) lnspect parwneutral switch (Refer to section K) or clutch switch (Refer to page T-105) lnspect vehicle speed sensor or wire harness (Refer to page T-106) Gartner Banana

AUDIO T Symptom: Speaker(s) do not operate (Without headrest speakers.) I L/ Possible cause Antitheft system activated Damaged audio unit Open circuit in wiring harness Poor connection of connector Damaged speaker Step 1 Check if the antitheft system has been activated. Turn the ignition switch to ACC and note the display. - - - Display CODE flashes Step 2 1. Remove the audio unit. (Refer to page T-145.) 2. Check the connections of the ground wire and the short plug. 3. If a connection is poor or loose, repair or replace it. 4. If the connections are OK, go to Step 3. Action Deactive antitheft system (page T-120) and go to step 2 Err flashes Clock No indication Step 3 1. Turn the ignition switch to ACC. 2. Measure the voltage at the following terminal-wires of the audio unit connector. B+: Battery positive voltage Have audio unit changed at a Panasonic service company Go to Step 4 Go to Ste~ 2 Terminal I Voltage I Action I B+ I Check C (UR) terminal 1 I 1, - I B+ I Redace audio unit I 1- Check ROOM 10A fuse (UR) I Other 1 If ROOM 10A fuse is OK, repair wiring harness 1 . . Check CIGAR 15A fuse If CIGAR 15A fuse is OK, repair wiring harness (CIGAR 15A fuse - Audio unit) A I I (ROOM 10A fuse - Audio unit) - I I Other Gartner Banana

AUDIO T Step 7 1. Disconnect the audio unit connector (12-pin). 2. Check for continuity between the audio unit connector and door speaker connector. M (VY) 1 2-pin tc B (WG) 2-pin Right door N (L) 12-pin ++ A (RAN) 2-pin K (WG) 12-pin ++ B (WG) P-pin Left door L [WWI 124n tc A IWW) 241 Spaker 3. If correct, replace the audio unit. 4. If not as specified, repair the wiring. Audio connector rp Symptom: Speaker(s) do not operate (With headrest speakers.) I 'peaker I Continuity I connector Possible cause Antitheft system activated Damaged audio unit - Open circuit in wiring harness GROUND WIRE Poor connection of connector Damaged speaker Step 1 Check if the antitheft system has been activated. Turn the ignition switch to ACC and note the display. Display CODE flashes Step 2 1. Remove the audio unit. (Refer to page T-145.) 2. Check the connections of the ground wire and the short plug. 3. If a connection is poor or loose, repair or replace it. 4. If the connections are OK, go to Step 3. Action Deactive antitheft system (page T-120) and go to step 2 Err flashes Clock No indication Have audio unit changed at a Panasonic service company Go to Step 4 Go to Step 2 Gartner Banana

SRS AIR BAG SYSTEM SERVICE WARNINGS Component Disassembly Disassembling and reassembling the components of the air bag system can render the system inopera- tive, which may result in serious injury or death in the event of an accident. Do not disassemble any air bag system components. Wiring Harness Repair Incorrectly repairing an air bag system wiring har- ness can accidently deploy the air bag, which can cause serious injury. If a problem is found in the sys- tem wiring, replace the wiring harness. Do not try to repair it. Air Bag Module Inspection Inspecting the air bag module with an ohmmeter can deploy the air bag, which can cause serious injury. Do not use an ohmmeter to inspect the air bag mod- ule. Air Bag Module Handling A live (undeployed) air bag may accidently deploy when it is handled and cause serious injury. When carrying a live air bag module, point the trim cover away from your body to lessen the chance of injury in case it deploys. A live air bag placed face down on a surface is dan- gerous. If the air bag deploys, the motion of the mod- ule can cause serious injury. Always face the trim cover up to reduce the motion of the module in case it accidently deploys. Gartner Banana

T SRS AIR BAG SYSTEM GENERALPROCEDURES Before Servicing 1. Deactivate the audio antitheft system, if installed. (Refer to page T-120.) 2. Disconnect the negative battery cable. 3. Remove the lower panel. 4. Disconnect the orange and blue clock spring connec- tors. 5. Remove the glove compartment. 6. Disconnect the orange and blue passenger-side air bag module connectors. I , 46UOTXd21 TROUBLESHOOTING Troubleshootinn Procedure The air bag diagnostic module has a self-diagnosis function that flashes or illuminates the AIR BAG sys- tem warning light to indicate trouble in the air bag system. The trouble can be determined by the warning light illumination or flashing pattern. If the light does not illuminate but the system still has trouble, a warn- ing buzzer will sound 5 cycles of 5 times each. . . Flowchart I START Troubleshoot warning light circuit Does AIR BAG system warning light illuminate for 4-8 secs and I I Yes t Refer to service code table and troubleshoot system Press horn switch while turning steering wheel. Does horn sound? I I I Yes Reconnect connectors Are air bag module and horn switch connectors properly con- nected to clock spring connec- tor? Yes I I I I Troubleshooting horn circuit - Gartner Banana

SRS AIR BAG SYSTEM T Service Code Table (With passenger-side air bag) Possible cause Flowchart No. Poor connection of diagnostic module priority connector Open circuit or poor connection of power source circuit code Output signal (Air bag system warning light) Remains ON Damaged D-sensor (D-sensor ON) 2 Poor installation of S-sensor Damaged S-sensor (S-sensor ON) 12 5 22 OFF OFF Open connection in S-sensor feed circuit S-sensor diagnosis circuit open High resistance or open circuit in driver- 8 32 OFF side air bag module circuit High resistance or open circuit in pas- senger-side air bag module circuit Low resistance in driver-side air bag module circuit I 11 1 35 ION- OFF b Low resistance in passenger-side air bag module circuit Open circuit between diagnostic module 10 and D-sensor - Poor installation of right D-sensor 113 144 ION- OFF 34 OFF Poor installation of center D-sensor 14 I 15 1 46 ION- OFF Poor installation of left D-sensor 45 System-down fuse burnt OFF 1 17 1 52 ( ON ml flk OFF Damaged back-up battery Damaged diagnostic module I 18 I 53 IoNm[~ OFF Poor connection of all D-sensor 19 I I I w Note If two or more troubles exist in the air bag system, the warning light indicates the cause of the trouble with the highest priority. T-163 99 Flashes quickly and continuously Gartner Banana

SRS AIR BAG SYSTEM T Possible cause Defective diagnostic module Defective S-sensor Defective wiring harness Step 1 Carry out "Before Servicing" procedure under GENER- AL PROCEDURES, page T-160. Service Code 12 Flowchart No.2 Step 2 Check the EGI IJN fuse. Symptom I Fuse I Action I Step 3 1. Disconnect the diagnostic module connector. 2. Connect the negative battery cable. 3. Measure the voltage at terminal 1 L (WIG) of the diagnos- tic module connector. OK Burnt B+: Battery positive voltage Voltage Action I Go to Step 3 Go to Step 4 Step 4 1. Disconnect the diagnostic module connector. 2. Check for continuity between terminal 1L (WIG) of the diagnostic module connector and ground. B+ Other Replace diagnostic module Repair wiring harness (EGI INJ fuse - Diagnostic module) I NO I GO to Step 5 I Continuity Yes Step 5 Check for continuity between terminal 1H (GIB) of the diagnostic module connector and ground. Continuity I Action Action Repair wiring harness (EGI INJ fuse - Diag- nostic module) and replace the fuse Yes ( Go to Step 6 No Replace diagnostic module (Refer to page T-208) Gartner Banana