1997 MAZDA MX-5 sensor

1. Ensure all connections are clean and tight. Repair as needed. Turn ignition on. Using voltmeter,
backprobe TCM connector (as applicable). Measure voltage between ground and specified terminal. See
DTC P0705 VOLTAGE TEST
table. If all voltages are within specification, go to step 5 . If any voltage
is not within specification, go to next step.
DTC P0705 VOLTAGE TEST
2. Check continuity of circuits between transmission range switch and TCM. See appropriate wiring
diagram in WIRING DIAGRAMS
. Repair as needed. If all circuits are okay, go to next step.
3. Disconnect negative battery cable. Disconnect transmission range switch harness connector. Inspect
continuity of transmission range switch internal circuits. See TRANSMISSION RANGE SWITCH

under COMPONENT TESTING. Replace as needed. If switch is okay, go to next step.
4. Reconnect negative battery cable. Turn ignition on. Measure voltage at terminal "I" (Black/Blue wire) on
transmission range switch harness connector. If battery voltage does not exist, repair Black/Blue wire
between switch and ignition switch. If battery voltage exists, go to next step.
5. Road test vehicle. Retrieve DTC. If code P0705 is still present, replace TCM. If code is no longer present,
system is okay.
DTC P0710: TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR CIRCUIT MALFUNCTION
& DTC P0711: TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR CIRCUIT
RANGE/PERFORMANCE
Condition
Voltage input to TCM is less than .1 volt or greater than 5.0 volts. Possible causes for condition are:
Transmission fluid temperature sensor malfunction.
Damaged wiring or connectors between transmission fluid temperature sensor and TCM.
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.
TCM Terminal
No.Measured
Voltage
Range Switch Position
2B0"P" Or "N"
2B10-14"R", "D", "S" Or "L"
2D10-14"D"
2D0All Except "D"
2F10-14"S"
2F0All Except "S"
2H10-14"L"
2H0All Except "L"

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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2. Measure voltage between terminal No. 1G (Green wire) and No. 2P (Black/Light Blue wire) on TCM
connector. Voltage should be about 3.3 volts at 77°F (25°C). If voltage is within specifications, go to step
6 . If voltage is not within specifications, go to next step.
3. Turn ignition off. Disconnect TCM harness connector. Measure resistance between terminals No. 1G and
No. 2P. See TFT SENSOR SPECIFICATIONS
table. If resistance is within specification, go to step 6 .
If resistance is not within specification, go to next step.
4. Inspect TFT sensor. Disconnect TFT sensor harness connector. Measure resistance between connector
terminals. See TFT SENSOR SPECIFICATIONS
table. If resistance is within specification, go to step
6 . If resistance is not within specification, replace TFT sensor.
5. Check continuity of circuits between TFT sensor and TCM. See appropriate wiring diagram in WIRING
DIAGRAMS . Repair as needed. If circuit is okay, go to next step.
6. Reconnect all harness connectors. Road test vehicle. Retrieve DTC. If code P0710 or P0711 is still
present, replace TCM. If code is no longer present, system is okay.
TFT SENSOR SPECIFICATIONS
DTC P0715: INPUT/TURBINE SPEED SENSOR
Condition
Input/Turbine speed sensor signal is not input to TCM when vehicle is moving. Possible causes for condition
are:
Input/Turbine speed sensor malfunction.
Damaged wiring or connectors between turbine speed sensor and TCM.
TCM malfunction.
Diagnosis & Repair Procedure
1. Turn ignition on. Using voltmeter, backprobe TCM harness connector. DO NOT disconnect connector.
Measure AC voltage between terminals No. 2J (positive) and No. 2L (negative). Voltage should be 0-.1
volts when idling and zero with engine stopped. If voltage is within specification, go to step 5 . If voltage
is not within specification, go to next step.
2. Turn ignition off. Disconnect TCM harness connector. Check for continuity between terminals No. 2J
(Yellow/Green wire) and No. 2L (Yellow/Blue wire). If continuity is present, go to step 5 . If continuity
is not present, go to next step.
3. Inspect sensor. See INPUT/TURBINE SPEED SENSOR
under COMPONENT TESTING. Repair as
needed. If sensor is okay, go to next step.
4. Check continuity of circuits between input/turbine speed sensor and TCM. See appropriate wiring
dia
gram in WIRING DIAGRAMS . Repair as needed. If circuits are okay, go to next step.
Fluid Temperaturek/ohms
68°F (20°C)2.5
140°F (60°C).6
176°F (80°C).35

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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Sunday, July 05, 2009 1:35:04 PMPage 11 © 2005 Mitchell Repair Information Company, LLC.

5. Reconnect all harness connectors. Road test vehicle. Retrieve DTC. If code P0715 is still present, replace
PCM. If code is no longer present, system is okay.
DTC P0725: ENGINE SPEED INPUT CIRCUIT MALFUNCTION
Condition
Engine speed input signal is not input to TCM. Possible causes are:
Crankshaft position sensor malfunction.
Damaged wiring or connectors between ECM and TCM.
ECM malfunction.
TCM malfunction.
Diagnosis & Repair Procedure
1. Ensure all connections are clean and tight. Repair as needed. Turn ignition on. Using voltmeter,
backprobe TCM harness connector. DO NOT disconnect connector.
2. Measure voltage between ground and terminal No. 1N (White wire) on TCM harness connector. Voltage
should be zero or 4.5-5.5 volts with engine stopped or 2-3 volts with engine idling. If voltage is within
specifications, go to step 7 . If voltage is not within specifications, go to next step.
3. Ignition off. Measure continuity between terminal No. 1N (White wire) on TCM harness connector and
terminal No. 4F (White wire) on ECM harness connector. If continuity is not present, repair wiring then
go to step 7 .
4. Using voltmeter, backprobe ECM harness connector. Measure voltage between ground and terminal No.
4H (Yellow/White wire). Voltage should be less than one volt with engine stopped or greater than one
volt with engine idling. If voltage is within specifications, go to step 7 . If voltage is not within
specifications, go to next step.
5. Inspect crankshaft position sensor. See appropriate SYSTEM & COMPONENT TESTS article in
ENGINE PERFORMANCE. Replace as needed. If sensor is okay, go to next step.
6. Turn ignition off. Using ohmmeter, backprobe TCM harness connector. DO NOT disconnect connector.
Measure resistance between terminals 1N (White wire) and 2P (Black/Light Green wire). If resistance is
7.2-8.0 ohms, go to next step. If resistance is not 7.2-8.0 ohms, replace TCM.
7. Reconnect all harness connectors. Road test vehicle. Retrieve DTC. If code P0725 is still present, replace
TCM. If code is no longer present, problem is intermittent.
DTC P0731: INCORRECT 1ST GEAR RATIO NOTE: If DTC P0335 is also present, repair it first and then proceed with this test. Go to
appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE and
perform test.
NOTE: If any following DTC is also present, repair it first and then proceed with this
test: DTC P0750
, P0755 , P0760 .

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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Shift solenoid 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. 2G (Orange wire) on TCM connector. During test
drive, voltage should be less than one volt when solenoid is off and battery voltage when solenoid is on.
See SOLENOID OPERATION
table under TCM OUTPUT DEVICES. If voltage is within
specification, go to step 5 . If voltage is not within specification, go to next step.
3. Turn ignition off. Disconnect TCM harness connector. Measure resistance between ground and terminal
No. 2G. If resistance is 13-27 ohms at 68°F (20°C), go to step 5 . If resistance is not 13-27 ohms at 68°F
(20°C), go to next step.
4. Inspect 2-3 shift solenoid and related circuits. See SOLENOID VALVES
under COMPONENT
TESTING. Repair as needed. If solenoid valve and related circuits are okay, go to next step.
5. Clear trouble codes and road test vehicle. Retrieve DTC. If DTC P0755 is still present, replace TCM. If
code is no longer present, system is okay.
DTC P0760: 3-4 SHIFT SOLENOID MALFUNCTION
Possible Causes:
Short or open circuit between TCM and solenoid.
TCM malfunction.
Shift solenoid 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. 2I (Blue wire) on TCM connector. During test drive,
voltage should be less than one volt when solenoid is off and battery voltage when solenoid is on. See
SOLENOID OPERATION
table under TCM OUTPUT DEVICES. If voltage is within specification, go
to step 5 . If voltage is not within specification, go to next step.
3. Turn ignition off. Disconnect TCM harness connector. Measure resistance between ground and terminal
No. 2E. If resistance is 13-27 ohms at 68°F (20°C), go to step 5 . If resistance is not 13-27 ohms at 68°F
(20°C), go to next step.
4. Inspect 3-4 shift solenoid and related circuits. See SOLENOID VALVES
under COMPONENT
TESTING. Repair as needed. If solenoid valve and related circuits are okay, go to next step.
5. Clear codes and road test vehicle. Retrieve DTC. If DTC P0760 is still present, replace TCM. If code is
no longer present, problem is intermittent. Further investigation may be necessary.
DTC P1720: VEHICLE SPEED SENSOR SIGNAL MISSING

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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Sunday, July 05, 2009 1:35:04 PMPage 17 © 2005 Mitchell Repair Information Company, LLC.

Condition
Vehicle speed sensor signal is not input to TCM. Possible causes are:
Vehicle speed sensor malfunction.
Vehicle speedometer sensor malfunction.
Damaged circuits or connectors between sensors and TCM.
Diagnosis & Repair Procedure
1. Ensure all connections are clean and tight. Repair as needed. Turn ignition on. Using voltmeter,
backprobe TCM harness connector. DO NOT disconnect connector. Test drive vehicle.
2. Measure voltage between ground and terminal No. 1P (Green/Red wire) on TCM harness connector.
During test drive voltage should be about 4 volts. When parked, voltage should be less than 1.5 or 7-9
volts. If voltage is within specifications, go to step 5 . If voltage is not within specifications, go to next
step.
3. Turn ignition off. Disconnect negative battery cable. Remove instrument cluster. Disconnect TCM
harness connectors. Ensure continuity exists on Green/Red wire between terminal No. 1P on TCM
connector and terminal No. 2F on instrument cluster harness left connector. Repair as needed. If
continuity exists, go to next step.
4. With combination meter removed, measure voltage between terminals No. 2F and 2D on combination
meter connector using analog voltmeter. Raise and support vehicle. Rotate rear wheels. If voltage pulse is
present, go to next step. If voltage pulse is not present, inspect speedometer cable. Replace as needed. If
cable is okay, replace combination meter or circuit board (as applicable).
5. Clear codes and road test vehicle. Retrieve DTC. If DTC 1720 is still present, replace TCM. If code is no
longer present, problem may be caused by poor connection. Repair as needed.
DTC P1743: TORQUE CONVERTER CLUTCH (TCC) SOLENOID MALFUNCTION
Possible Causes:
Short or open circuit between TCM and solenoid.
TCM malfunction.
Lock-up solenoid 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. 2K (Yellow/Black wire). Battery voltage should be
present with solenoid on and zero volts with solenoid off. If voltage is within specifications, go to step 5 .
If voltage is not within specifications, go to next step.
3. Turn ignition off. Disconnect TCM harness connector. Measure resistance between ground and terminal
No. 2K. If resistance is 13-25 ohms at 68°F (20°C), go to step 5 . If resistance is not 13-25 ohms at 68°F
(20°C),
go to next step.

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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4. Inspect lock-up solenoid and related circuits. See SOLENOID VALVES under COMPONENT
TESTING. Repair as needed. If solenoid valve and related circuits are okay, go to next step.
5. Clear codes and road test vehicle. Retrieve DTC. If DTC P1743 is still present, replace TCM. If code is
no longer present, problem may be caused by poor connection. Repair as needed.
DTC P1765: 3-2 CONTROL SOLENOID VALVE MALFUNCTION
Possible Causes:
Short or open circuit between TCM and solenoid.
TCM malfunction.
3-2 control solenoid 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. Drive vehicle and measure voltage between ground and terminal No. 2M (Blue/Orange wire). Battery
voltage should be present with solenoid on during 3-2 or 4-3 downshift, and zero volts with solenoid off.
If voltage is within specifications, go to step 5 . If voltage is not within specifications, go to next step.
3. Turn ignition off. Disconnect TCM harness connector. Measure resistance between ground and terminal
No. 2M. If resistance is 13-27 ohms at 68°F (20°C), go to step 5 . If resistance is not 13-27 ohms at 68°F
(20°C), go to next step.
4. Inspect 3-2 control clutch solenoid and related circuits. See SOLENOID VALVES
under
COMPONENT TESTING. Repair as needed. If solenoid valve and related circuits are okay, go to next
step.
5. Clear codes and road test vehicle. Retrieve DTC. If DTC P1765 is still present, replace TCM. If code is
no longer present, problem may be caused by poor connection. Repair as needed.
DTC P1790: THROTTLE POSITION (TP) SENSOR MALFUNCTION
Condition
TP sensor voltage is less than one volt or more than 4.9 volts. Possible causes are:
Poor harness connection at TP sensor.
Circuit fault between TP sensor and ECM or TCM.
TP sensor malfunction.
ECM or TCM malfunction.
Diagnosis & Repair Procedure
NOTE: If DTC P0725 is also present, repair it first and then proceed with this test.

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1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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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

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1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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HOLD SWITCH
1. Turn ignition on. Ensure HOLD indicator illuminates with switch depressed. Ensure indicator light is not
illuminated when switch is released. If switch is not working as described, go to next step.
2. Access switch connector under center console. Disconnect connector. Check continuity between
terminals "A" and "B". See Fig. 6
. Continuity should exist when switch is depressed. When switch is
released, continuity should not exist. Replace as needed. If HOLD switch system does not function
correctly, inspect circuits between switch and TCM. See appropriate wiring diagram in WIRING
DIAGRAMS .
Fig. 6: Testing HOLD Switch

Courtesy of MAZDA MOTORS CORP.
INPUT/TURBINE SPEED SENSOR IDENTIFICATION
table under SELF-DIAGNOSTIC SYSTEM. For circuit or wire
color identification, see appropriate wiring diagram in WIRING DIAGRAMS
.

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
Microsoft
Sunday, July 05, 2009 1:35:04 PMPage 21 © 2005 Mitchell Repair Information Company, LLC.