1997 MAZDA MX-5 Factory Repair Manual

Courtesy of MAZDA MOTORS CORP.
Fig. 4: Identifying TCM Component Connector Terminals

Courtesy of MAZDA MOTORS CORP.
Fig. 5: Identifying ECM Component Connector Terminals

Courtesy of MAZDA MOTORS CORP.
DIAGNOSTIC TESTS
DTC P0705: TRANSMISSION RANGE SWITCH CIRCUIT MALFUNCTION & DTC P0706:
TRANSMISSION RANGE SWITCH CIRCUIT RANGE/PERFORMANCE
Condition
No signal is received from range switch or more than 2 signals are received at one time. Possible causes for
either condition are:
Transmission range switch malfunction.
Damaged wiring or connectors between transmission range switch and TCM.
TCM malfunction.
Diagnosis & Repair Procedure
NOTE: For connector terminal identification, see COMPONENT CONNECTOR
IDENTIFICATION table under SELF-DIAGNOSTIC SYSTEM. For circuit or wire
color identification, see appropriate wiring diagram in WIRING DIAGRAMS
.

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1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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Sunday, July 05, 2009 1:35:03 PMPage 9 © 2005 Mitchell Repair Information Company, LLC.

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

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1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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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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Sunday, July 05, 2009 1:35:04 PMPage 12 © 2005 Mitchell Repair Information Company, LLC.

Condition
TCM outputs solenoid pattern of 1st gear when gear ratio is other than 1st gear. Possible causes are:
Low ATF level.
Low line pressure.
Control valve stuck.
Solenoid valve malfunction.
TCM malfunction.
Diagnosis & Repair Procedure
1. Ensure ATF level and condition is okay. Check line pressure and stall speed. See LINE PRESSURE
TEST and STALL SPEED under TESTING in MAZDA NC4A-EL OVERHAUL article. Repair any
components as necessary. If malfunction is not present, go to next step.
2. Inspect 1-2, 2-3 and 3-4 shift solenoid valves. See SOLENOID VALVES
under COMPONENT
TESTING. Repair as needed. If solenoid valves are okay, go to next step.
3. Inspect valve body. Ensure all valves operate smoothly. Repair as needed. If valve body is okay, go to
next step.
4. Clear DTC and retest. See CLEARING CODES
. If code P0731 is still present, replace TCM. If code is
no longer present and symptom still exists, problem may be caused by intermittent clutch slippage.
Further investigation may be required. See MAZDA NC4A-EL OVERHAUL article.
DTC P0732: INCORRECT 2ND GEAR RATIO
Condition
TCM outputs solenoid pattern of 2nd gear when gear ratio is other than 2nd gear. Possible causes are:
Low ATF level.
Direct clutch slippage.
One-way clutch slippage.
Faulty band servo.
Low line pressure.
Control valve stuck.
Solenoid valve malfunction.
TCM malfunction.
Diagnosis & Repair Procedure
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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Sunday, July 05, 2009 1:35:04 PMPage 13 © 2005 Mitchell Repair Information Company, LLC.

1. Ensure ATF level and condition is okay. Check line pressure and stall speed. See LINE PRESSURE
TEST and STALL SPEED under TESTING in MAZDA NC4A-EL OVERHAUL article. Repair any
components as necessary. If malfunction is not present, go to next step.
2. Inspect 1-2, 2-3 and 3-4 shift solenoid valves. See SOLENOID VALVES
under COMPONENT
TESTING. Repair as needed. If solenoid valves are okay, go to next step.
3. Inspect valve body. Ensure all valves operate smoothly. Repair as needed. If valve body is okay, go to
next step.
4. Clear DTC and retest. See CLEARING CODES
. If code P0732 is still present, replace PCM. If code is
no longer present and symptom still exists, problem may be caused by intermittent clutch slippage.
Further investigation may be required. See MAZDA NC4A-EL OVERHAUL article.
DTC P0733: INCORRECT 3RD GEAR RATIO
Condition
TCM outputs solenoid pattern of 3rd gear when gear ratio is other than 3rd gear. Possible causes are:
Low ATF level.
Direct clutch slippage.
One-way clutch slippage.
Front clutch slippage.
Low line pressure.
Control valve stuck.
Solenoid valve malfunction.
TCM malfunction.
Diagnosis & Repair Procedure
1. Ensure ATF level and condition is okay. Check line pressure and stall speed. See LINE PRESSURE
TEST and STALL SPEED under TESTING in MAZDA NC4A-EL OVERHAUL article. Repair any
components as necessary. If malfunction is not present, go to next step.
2. Inspect 1-2, 2-3 and 3-4 shift solenoid valves. See SOLENOID VALVES
under COMPONENT
TESTING. Repair as needed. If solenoid valves are okay, go to next step.
3. Inspect valve body. Ensure all valves operate smoothly. Repair as needed. If valve body is okay, go to
next step.
4. Clear DTC and retest. See CLEARING CODES
. If DTC P0733 is still present, replace PCM. If code is
no longer present and symptom still exists, problem may be caused by intermittent clutch slippage.
Further investigation may be required. See MAZDA NC4A-EL OVERHAUL article.
DTC P0734: INCORRECT 4TH GEAR RATIO 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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Condition
TCM outputs solenoid pattern of 3rd gear when gear ratio is other than 3rd gear. Possible causes are:
Low ATF level.
Band servo slippage.
Front clutch slippage.
Low line pressure.
Control valve stuck.
Solenoid valve malfunction.
TCM malfunction.
Diagnosis & Repair Procedure
1. Ensure ATF level and condition is okay. Check line pressure and stall speed. See LINE PRESSURE
TEST and STALL SPEED under TESTING in MAZDA NC4A-EL OVERHAUL article. Repair any
components as necessary. If malfunction is not present, go to next step.
2. Inspect 1-2, 2-3 and 3-4 shift solenoid valves. See SOLENOID VALVES
under COMPONENT
TESTING. Repair as needed. If solenoid valves are okay, go to next step.
3. Inspect valve body. Ensure all valves operate smoothly. Repair as needed. If valve body is okay, go to
next step.
4. Clear DTC and retest. See CLEARING CODES
. If DTC P0734 is still present, replace PCM. If code is
no longer present and symptom still exists, problem may be caused by intermittent clutch slippage.
Further investigation may be required. See MAZDA NC4A-EL OVERHAUL article.
DTC P0740: TORQUE CONVERTER CLUTCH MALFUNCTION
Condition
TCM outputs TCC signal, but TCC does not operate. Possible causes are:
Low ATF level.
Low line pressure.
Torque converter slippage.
Control valve stuck.
Lock-up solenoid valve malfunction.
TCM malfunction.
Diagnosis & Repair Procedure
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
Microsoft
Sunday, July 05, 2009 1:35:04 PMPage 15 © 2005 Mitchell Repair Information Company, LLC.

1. Inspect ATF level and condition. Correct as needed. If fluid level and condition is okay, check line
pressure. See LINE PRESSURE TEST under TESTING in MAZDA NC4A-EL OVERHAUL article.
Follow repair recommendations if line pressure is not within specifications. If line pressure is okay, go to
next step.
2. Inspect lock-up solenoid. See SOLENOID VALVES
under COMPONENT TESTING. Repair as
needed. If solenoid valve is okay, go to next step.
3. Inspect lock-up control valve in valve body. If valve is okay, go to next step.
4. Using an EC-AT tester connected to TCM, ensure that engine speed and turbine speed during TCC lock-
up in 4th gear are the same. If speeds are different, replace torque converter. If speeds are the same, go to
next step.
5. Clear DTC. See CLEARING CODES
. Retrieve DTC. If DTC P0740 is still present, replace TCM. If
code is no longer present and symptom still exists, problem may be caused by intermittent TCC slippage.
Further investigation may be required. See MAZDA NC4A-EL OVERHAUL article.
DTC P0750: 1-2 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. 2E (Blue/Yellow 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 1-2 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 DTC and road test vehicle. Retrieve DTC. If DTC P0750 is still present, replace TCM. If code is no
longer present, system is okay.
DTC P0755: 2-3 SHIFT SOLENOID MALFUNCTION
Possible Causes:
Short or open circuit between TCM and solenoid.
TCM malfunction.

1997 Mazda MX-5 Miata
1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls
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Sunday, July 05, 2009 1:35:04 PMPage 16 © 2005 Mitchell Repair Information Company, LLC.