Mazda MX-5 Miata (1997+). Manual — part 18

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

Disconnect output speed sensor connector. See Fig. 3 . Measure resistance between terminals. Resistance
should be 245 ohms. Replace as needed.

SOLENOID VALVES (EXCEPT TCC SOLENOID)

Disconnect negative battery cable. Disconnect transmission solenoid harness connector. See Fig. 3 . Note that
solenoids ground through transmission case. Check resistance between connector terminals and ground. See
Fig. 7 . Resistance should be 13-27 ohms. Replace solenoids as necessary. See SOLENOID VALVE
IDENTIFICATION table. Ensure transmission case is grounded.

Fig. 7: Identifying Solenoid Valve Terminals
Courtesy of MAZDA MOTORS CORP.

SOLENOID VALVE IDENTIFICATION

TCC SOLENOID

Disconnect negative battery cable. Disconnect TCC solenoid harness connector. See Fig. 3 . Check resistance

Solenoid Valve

(1)

Terminal No.

1-2 Shift Solenoid

C

2-3 Shift Solenoid

D

3-4 Shift Solenoid

A

3-2 Control

B

(1)

See Fig. 7 for terminal identification.

1997 Mazda MX-5 Miata

1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls

between connector terminals and ground. Resistance should be 13-25 ohms. Replace solenoids as necessary.
Ensure transmission case is grounded.

VEHICLE SPEED SENSOR (VSS)

Disconnect negative battery cable. Remove combination meter. Disconnect harness connectors and speedometer
cable. Connect analog voltmeter leads to meter terminals "A" and "B". See Fig. 8 . Using appropriate
screwdriver, rotate speedometer cable shaft. If voltmeter needle does not fluctuate, replace sensor.

Fig. 8: Testing Vehicle Speed Sensor
Courtesy of MAZDA MOTORS CORP.

TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR

Disconnect TFT sensor harness connector. Sensor is threaded into cooler line banjo mounting on side of
transmission case. Measure resistance between connector terminals. See TFT SENSOR SPECIFICATIONS
table.

TFT SENSOR SPECIFICATIONS

NOTE:

Vehicle speed sensor signal is input to TCM from combination meter driven by
speedometer cable.

Fluid Temperature

k/ohms

68°F (20°C)

2.5

140°F (60°C)

.6

1997 Mazda MX-5 Miata

1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls

TRANSMISSION RANGE SWITCH

1. Check for starter operation with ignition switch in START position and selector lever in "P" and "N"

position only. Ensure back-up lights illuminate with ignition in ON position and selector lever in "R"
position. If any problems are found, go to next step.

2. Disconnect transmission range switch connector. See Fig. 3 . Check continuity between specified

terminals. See Fig. 9 . If continuity is not as specified, replace switch.

Fig. 9: Checking Transmission Range Switch
Courtesy of MAZDA MOTORS CORP.

176°F (80°C)

.35

1997 Mazda MX-5 Miata

1997 AUTOMATIC TRANSMISSIONS NC4A-EL Electronic Controls