DTC P0742 [FN4A-EL]

id0502a1808000

DTC P0742

Torque converter clutch (TCC) stuck ON

DETECTION CONDITION

• All of following conditions are satisfied under each of following throttle conditions.
- ATF temperature 20 °C {68 °F} or above.
- Driving in 4GR at D range.
- Engine running.
- Turbine speed within 225-4,988 rpm.
- Vehicle speed below 70 km/h {43 mph}.
- Torque converter clutch (TCC) no operation
- Difference between engine speed and turbine speed below 50 rpm
- DTC P0734 not output
• Throttle conditions.
- Throttle opening angle (TP PID) above 10.1% and 5 s or more have passed.
- Throttle opening angle (TP PID) within 3.1-10.1% and 3 s or more have passed.
- Throttle opening angle at closed throttle position and 5 s or more have passed.
Diagnostic support note:
• This is a continuous monitor (CCM).
• MIL does not illuminate if PCM detects the above malfunction conditions during first drive cycle.
• PENDING CODE is not available.
• FREEZE FRAME DATA is not available.
• HOLD indicator light flashes.
• DTC is stored in the PCM memory.

POSSIBLE CAUSE

• ATF level low
• Deteriorated ATF
• Shift solenoids A, B, C, D, E, and pressure control solenoid stuck
• Line pressure low
2-4 brake band slipping
3-4 clutch slipping
• Control valve stuck
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1

VERIFY RELATED REPAIR INFORMATION AVAILABILITY

• Check for related Service Bulletins availability.
• Is any related repair information available?
Yes
Perform repair or diagnosis according to available repair information.
• If vehicle is not repaired, go to next step.
No
Go to next step.
2

CHECK ATF CONDITION

• Turn the ignition switch off.
• Check ATF condition.
- Clear red: Normal
- Milky: Water mixed in fluid
- Reddish brown: Deteriorated ATF
• Is it normal?
Yes
Go to next step.
No
If ATF color is milky or reddish brown, replace ATF, then go to Step 4.
3

CHECK ATF LEVEL

• Start engine.
• Warm up ATX.
• Is ATF level within specification?
Yes
Go to next step.
No
Adjust ATF level, then go to Step 6.
4

INSPECT LINE PRESSURE

• Start engine.
• Measure line pressure.

Specification

D, S, L range

Idle: 330-470 kPa {3.4-4.7 kgf/cm2,

48-68 psi}

Stall: 1,030-1,190 kPa {10.5-12.1 kgf/cm2,

150-172 psi}

R position

Idle: 490-710 kPa {5.0-7.2 kgf/cm2,

71-102 psi}

Stall: 1,700-2,050 kPa {17.4-20.9 kgf/cm2, 247-297 psi}

• Is line pressure within specification?
Yes
Go to next step.
No
• All ranges: Replace oil pump or control valve body, then go to Step 6.
• Any ranges: Replace ATX, then go to Step 6.
(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-99).)
5

CHECK OPERATION OF EACH VALVE AND EACH SPRING

• Turn the ignition switch off.
• Remove control valve body.
• Disassemble control valve body.
• Is each valve operation normal and is return spring normal?
(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-99).)
Yes
Replace ATX, then go to next step.
(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-99).)
No
Repair or replace shift valve and return spring, then go to next step.
(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-99).)
6

VERIFY TROUBLESHOOTING OF DTC P0742 COMPLETED

• Make sure to reconnect all disconnected connectors.
• Clear DTC from memory using WDS or equivalent.
• Start engine.
• Warm up engine and ATX.
• Drive vehicle under following.
- ATF temperature: 20 °C {68 °F} or above
- Drive in D range, 4th gear (TCC not in operation)
- Vehicle speed: below 70 km/h {43 mph}.
• Throttle conditions
- Throttle opening angle (TP PID) above 10.1% and 5 s or more have passed.
- Throttle opening angle (TP PID) within 3.1-10.1% and 3 s or more have passed.
- Throttle opening angle at closed throttle position and 5 s or more have passed.
• Are any DTCs present?
Yes
Replace PCM, then go to next step.
No
Go to next step.
7

VERIFY AFTER REPAIR PROCEDURE

• Perform "After Repair Procedure".
• Are any DTCs present?
Yes
Go to applicable DTC inspection.
No
Troubleshooting completed.