1997 MAZDA MX-5 check engine

1. Ensure all connections are clean and tight. Repair as needed. Ensure that TP sensor is adjusted correctly.
See appropriate ON-VEHICLE ADJUSTMENTS article in ENGINE PERFORMANCE. Turn ignition
on. Access TCM connectors. Using voltmeter, backprobe harness connectors. DO NOT disconnect
connectors. Go to next step.
2. Measure voltage between ground and terminal No. 2T (Red/Black wire) on TCM harness connector. With
throttle closed, voltage should be .1-1.1 volts. With wide open throttle, voltage should be 3.1-4.4 volts. If
voltage is within specification, go to step 5 . If voltage is not within specification, go to next step.
3. Measure voltage between ground and terminal No. 2A (Light Green/White wire) on TCM harness
connector. With ignition on, voltage should be 4.5-5.5 volts. With ignition off, voltage should be zero
volts. If voltage is within specification, go to step 5 . If voltage is not within specification, go to next step.
4. Inspect circuits between TP sensor and TCM. See appropriate wiring diagram under WIRING
DIAGRAMS . Repair as needed. If circuits are okay between sensor and TCM, go to next step.
5. Clear codes, and road test vehicle. Retrieve DTC. If DTC P1790 is still present, replace TCM. If code is
no longer present, system is okay.
DTC P1795: IDLE SWITCH OPEN OR SHORT
Condition
Closed throttle position switch is ON and TP sensor position is closed. Possible causes are:
Damaged wiring or connectors between closed throttle position switch and TCM.
Closed throttle position switch malfunction.
TCM malfunction.
Diagnosis & Repair Procedure
1. Ensure all connections are clean and tight. Repair as needed. Turn ignition on. Access TCM connectors.
Using voltmeter, backprobe harness connectors. DO NOT disconnect connectors. Go to next step.
2. Measure voltage between ground and terminal No. 1O (Red wire) on TCM harness connector. With
throttle closed, battery voltage should be present. With wide open throttle, voltage should be zero volts. If
voltage is within specification, go to step 5 . If voltage is not within specification, go to next step.
3. Inspect circuits between closed throttle position switch and TCM. See appropriate wiring diagram under
WIRING DIAGRAMS
. Repair as needed. If circuits are okay between sensor and TCM, go to next
step.
4. Disconnect battery negative cable. Disconnect closed throttle position switch connector. Check for
continuity between closed throttle position switch terminals. If continuity exists, go to next step. If
continuity does not exist, replace or adjust throttle position sensor.
5. Clear codes, and road test vehicle. Retrieve DTC. If DTC P1795 is still present, replace TCM. If code is
no longer present, problem is intermittent. Further investigation is required.
COMPONENT TESTING
NOTE: For connector terminal identification, see COMPONENT CONNECTOR

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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Remove master cylinder to gain access to push rod. To check screw adjustment, fabricate a gauge. See Fig. 1.
With engine running and vacuum line connected to booster, place gauge against master cylinder mounting
surface of booster. Adjust push rod screw by turning it until end of screw just touches inner edge of gauge slot.
Fig. 1: Adjusting Brake Booster Push Rod (B2300, B3000 & B4000)

Courtesy of FORD MOTOR CO.
REAR BRAKE SHOES ADJUSTMENT
B2300, B3000 & B4000
NOTE: Rear brakes are self-adjusting and require manual adjustment only if brake
shoes have been replaced.

1997 Mazda MX-5 Miata
BRAKE SYSTEM 1995-97 BRAKES Mazda - Disc & Drum
Microsoft
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929
1. Depress brake pedal several times. Depress parking brake pedal several times with a force of 44 lbs. (20
kg). If stroke is 5-7 notches, parking brake is properly adjusted. If stroke is not 5-7 notches, rotate
adjusting nut, located under parking brake pedal, until stroke is within specification.
2. Ensure rear brakes do not drag. Ensure parking brake warning light illuminates when brake pedal is
depressed one notch.
BRAKE PEDAL FREE PLAY
With engine off, depress pedal a few times to eliminate vacuum. Depress brake pedal by hand and check pedal
free play. See BRAKE PEDAL FREE PLAY SPECIFICATIONS
. Adjust play by loosening push rod lock
nut. Turn push rod until correct free play is obtained. Tighten push rod lock nut to 18-25 ft. lbs. (24-34 N.m).
BRAKE PEDAL FREE PLAY SPECIFICATIONS
BRAKE PEDAL HEIGHT & STOPLIGHT SWITCH
Miata, MPV, MX-3, MX-6, RX7, 626 & 929
1. Released pedal height is measured from carpet surface on vertical portion of firewall to pedal pad center.
Disconnect stoplight switch electrical connector. Loosen lock nut on stoplight switch. Rotate switch away
from pedal. Loosen push rod lock nut. Rotate push rod until correct pedal height is obtained. See
BRAKE PEDAL HEIGHT SPECIFICATIONS
.
2. Adjust pedal free play. See BRAKE PEDAL FREE PLAY
. Tighten push rod lock nut to 18-25 ft. lbs.
(24-34 N.m).
3. Rotate stoplight switch until it contacts pedal and then rotate an additional 1/2 turn. Tighten stoplight
switch lock nut 10-13 ft. lbs. (14-18 N.m). Reconnect stoplight switch electrical connector.
4. Applied pedal height is measured from angled portion of firewall (without carpet) to pedal pad center.
Start engine. Depress brake pedal with 132 lbs. (60 kg) pressure.
5. Measure applied pedal hei
ght. See BRAKE PEDAL HEIGHT SPECIFICATIONS . If distance is not NOTE: On B2300, B3000 & B4000, brake pedal free play is built into pedal linkage and
is not adjustable.
ApplicationIn. (mm)
Miata, MPV & MX-3.16-.28 (4-7)
Millenia, MX-6, Protege & 626.16-.47 (4-12)
RX7.12-.31 (3-8)
929.12-.47 (8-12)
NOTE: B2300, B3000 & B4000 are equipped with dual brake master cylinder and
vacuum booster. System is designed to permit full stroke of master cylinder
when brake pedal is fully depressed. Brake pedal height adjustment is not
required.

1997 Mazda MX-5 Miata
BRAKE SYSTEM 1995-97 BRAKES Mazda - Disc & Drum
Microsoft
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as specified, check for air in system, rear brake adjustment (drum brakes) or worn shoes or pads.
BRAKE PEDAL HEIGHT SPECIFICATIONS
Millenia & Protege
1. Released pedal height is measured between brake pedal and stoplight switch mounting bracket. See Fig.
3 . Disconnect stoplight switch electrical connector and remove switch. Measure length "L" between
stoplight switch mounting bracket and brake pedal. See Fig. 3
. On Millenia, length should be .79-
.90" (20-23 mm). On Protege, length should be .71-.86" (18-22 mm).
2. On all models, if clearance is as specified, install stoplight switch. No adjustment is necessary. If
clearance is not as specified, loosen lock nut "B" and rotate self-locking nut "A" counterclockwise until it
does not contact brake pedal.
3. Loosen push rod lock nut and rotate push rod until correct clearance between brake pedal and stoplight
switch mounting bracket is obtained. Tighten push rod lock nut. Rotate self-locking nut "A" clockwise
until clearance between brake pedal and end of self-locking nut "A" is .004-.039 (.1-1.0 mm). See Fig. 3
.
Tighten lock nut "B".
4. Install NEW stoplight switch. Stoplight switch is automatically adjusted by pulling back on brake pedal
until stoplight switch click noise is heard. Reconnect stoplight switch electrical connector. Check
stoplight operation. Adjust pedal free play. See BRAKE PEDAL FREE PLAY
. Tighten push rod lock
nut to 18-25 ft. lbs. (24-34 N.m).
5. Applied pedal height is measured from angled portion of firewall (without carpet) to pedal pad center.
Start engine. Depress brake pedal with 132 lbs. (60 kg) pressure. On Millenia, distance should be 2.7" (70
mm). On Protege, distance should be 3.8" (95 mm). On all models, if distance is not as specified, check
ApplicationIn. (mm)
Pedal Released
Miata6.8-7.1 (171-181)
MPV7.5-7.9 (191-201)
MX-37.6-7.7 (193-196)
MX-6 & 6267.5-7.7 (191-196)
RX76.5-6.9 (165-176)
9297.4-7.7 (188-195)
Pedal Applied (1)
Miata3.7 (95)
MPV, MX-6 & 6263.3 (85)
MX-32.8 (70)
RX73.9 (100)
9291.6 (40)
(1)Minimum height.
NOTE: When adjusting brake pedal height, a NEW stoplight switch must be used.
Stoplight switch can only be adjusted one time.

1997 Mazda MX-5 Miata
BRAKE SYSTEM 1995-97 BRAKES Mazda - Disc & Drum
Microsoft
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POWER BRAKE UNIT
1. With engine off, depress brake pedal several times. Press and hold brake pedal and start engine. If brake
pedal moves down slightly immediately after engine starts, power brake unit is operating. If brake pedal
does not move as specified, go to next step.
2. Run engine for 1-2 minutes. Stop engine. Press brake pedal several times and note if first pedal stroke is
longer than subsequent strokes. If first pedal stroke is longer than subsequent strokes, power brake unit is
operating. If length of strokes is equal, check valve and vacuum hose between vacuum source and power
brake unit. Repair as necessary, and go to next step.
3. Start engine. Press and hold brake pedal. Stop engine. Hold pedal down for about 30 seconds. If pedal
height remains at same height, power brake unit is operating. If pedal height recedes, check valve and
vacuum hose between vacuum source and power brake unit. Repair as necessary.
REMOVAL & INSTALLATION
FRONT DISC BRAKE PADS
Removal & Installation (B2300, B3000 & B4000)
1. To prevent master cylinder overflow when caliper piston is depressed, remove and discard some brake
fluid from master cylinder reservoir. Raise and support vehicle. Remove front wheel assemblies. Place a
large "C" clamp on caliper.
2. Tighten clamp to bottom piston in cylinder bore. Remove clamp. Remove 2 caliper pin bolts. Remove
caliper from rotor and wire aside. Slide brake pads off caliper anchor plate. Remove anchor plate (if
necessary). Replace pad if lining thickness is less than specified. See MINIMUM PAD LINING
SPECIFICATIONS (FRONT) .
3. To install, reverse removal procedure. Use "C" clamp and old pad to push caliper piston into piston bore
until piston bottoms out. Bleed air from brake system (if necessary).
Removal & Installation (Miata, Millenia, MPV, MX-6, 626 & 929)
1. Raise and support front of vehicle. Remove front wheel assemblies. Remove lower lock pin/guide bolt.
See Fig. 4
, Fig. 5 or Fig. 6 . Pivot caliper upward and support using rope.
2. Remove pads, shims, guide plates or pad guides and "V" springs (if equipped). Replace pad if lining
thickness is less than specified. See MINIMUM PAD LINING SPECIFICATIONS (FRONT)
.
3. To install, reverse removal procedure. Use Disc Brake Expander (49-0221-600C) and an old pad to push
piston full
y inward to install disc pads.
(38-46)

1997 Mazda MX-5 Miata
BRAKE SYSTEM 1995-97 BRAKES Mazda - Disc & Drum
Microsoft
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GENERATOR OUTPUT
1. Connect an ammeter (100-amp minimum) in-line between generator terminal "B" connector and terminal
"B" of wiring harness connector. See Fig. 1
. Turn headlights and all accessories on. Depress brake pedal.
Operate engine at 2500-3000 RPM.
2. Measure and record generator output. See GENERATOR MAXIMUM RATED OUTPUT
table. If
amperage is as specified, go to next step. If amperage is not as specified, repair or replace generator.
3. Turn off headlights and all accessories. Release brake pedal. Operate engine at 2500-3000 RPM and
measure amperage under no-load condition. No-load amperage should be 5 amps or greater. If amperage
is as specified, go to next step. If amperage is not as specified, repair or replace generator.
4. Operate engine at 2500-3000 RPM. Measure voltage between ground and terminals "S" and "L". If 14.1-
14.7 volts does not exist, repair or replace generator. If 14.1-14.7 volts exists, generator output is okay.
GENERATOR MAXIMUM RATED OUTPUT NOTE: Check generator wiring harness connections and drive belt tension. Battery
must be fully charged before testing. Wait at least 30 seconds after starting
engine before measuring system voltage.
CAUTION: Ensure generator terminal "B" does not contact ground.
ApplicationAmps
A/T70
M/T65

1997 Mazda MX-5 Miata
GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators
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Submerge other end of hose in container of brake fluid.
2. Fill reservoir with DOT 3 brake fluid. Have an assistant press and release clutch pedal several times, then
hold pedal down. With pedal pressed, loosen bleeder screw to let air and fluid escape.
3. Repeat step 2) until no more air bubbles emerge from hose. Tighten bleeder screw. Fill reservoir. Operate
clutch while inspecting for leaks. Check clutch and brake operation.
REMOVAL & INSTALLATION
CLUTCH ASSEMBLY
Removal (B2300, B2500, B3000 & B4000)
1. Disconnect negative battery cable. Shift transmission into Neutral. Remove gearshift lever. Raise and
support vehicle. Mark drive shaft flanges for installation reference. Remove drive shaft. Using Clutch
Disconnect Tool (T88T-70522-A), disconnect hydraulic line at transmission. See Fig. 2
. Plug hydraulic
line to prevent contamination. Disconnect wiring at transmission.
2. Remove starter. Remove exhaust components as necessary for clearance. On 4WD models, remove skid
plate and transfer case. On all models, secure transmission jack under transmission. Remove transmission
mount-to-crossmember nuts and bolts.
3. Remove nuts securing crossmember to frame side rails, and remove crossmember. Lower transmission
enough to gain access to transmission-to-engine block bolts. Remove transmission-to-engine block bolts.
Remove transmission.
4. If clutch parts are going to be reused, mark clutch cover and flywheel for reassembly reference. Loosen
pressure plate bolts evenly in crisscross pattern until springs are not under tension. Remove clutch cover
and clutch disc.
Inspection (B2300, B2500, B3000 & B4000)
1. Inspect disc for loose rivets, worn or defective springs, excessive wear, or oil contamination. Inspect
flywheel and clutch cover for burns, scoring, or grooves.
2. Measure flywheel and clutch cover runout. Resurface or replace flywheel and clutch cover if beyond
specification. See CLUTCH RUNOUT (MAXIMUM)
table.
3. Measure clutch disc runout. Replace disc if it is not to specification. See CLUTCH RUNOUT
(MAXIMUM) table. Inspect disc hub and input shaft splines for excessive wear. Hub must slide
smoothly on input shaft splines.
4. Inspect pilot bearing for wear. Apply inward pressure while rotating pilot bearing. If bearing sticks or has
excessive resistance, replace bearing. Check for tight fit in crankshaft. Replace as necessary. Inspect
release bearing for smooth operation, wear, damage, or looseness. Replace bearing as necessary.
CLUTCH RUNOUT (MAXIMUM)
ApplicationIn. (mm)
Disc0.028 (0.7)
Flywheel0.008 (0.20)

1997 Mazda MX-5 Miata
CLUTCH 1997-98 CLUTCHES Mazda - RWD
Microsoft
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Fig. 7: Exploded View Of Clutch Assembly (Typical)
Courtesy of MAZDA MOTORS CORP.
Inspection (Miata)
1. Inspect disc for loose rivets, worn springs, excessive wear, or oil contamination. Inspect flywheel and
clutch cover for burns, scoring, or grooves.
2. Measure flywheel and clutch cover runout. Resurface or replace flywheel and clutch cover if beyond
specification. See CLUTCH RUNOUT (MAXIMUM)
table. If flywheel ring gear is replaced, ensure
chamfer on flywheel teeth faces engine.
3. Measure clutch disc runout. Replace disc if it is not to specification. See CLUTCH RUNOUT
(MAXIMUM) table. Inspect disc hub and input shaft splines for excessive wear. Hub must slide
smoothly on input shaft splines.
4. Inspect pilot bearing for wear. Apply inward pressure while rotating pilot bearing. If bearing sticks or has
excessive resistance, replace bearing. Check for tight fit in crankshaft. Replace as necessary. Inspect
release bearing for smooth operation, wear, damage, or looseness. Replace bearing as necessary.

1997 Mazda MX-5 Miata
CLUTCH 1997-98 CLUTCHES Mazda - RWD
Microsoft
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