DTC code
P0740
Torque Converter Clutch Circuit Malfunction
Technical guide
Symptoms
- TCC shudder at highway speed
- poor fuel economy
- check engine light
Probable causes
- Torque converter clutch circuit fault
- failed TCC solenoid (very common)
- worn torque converter
- burnt ATF
- solenoid wiring
Diagnostic steps
- Check ATF condition - flush if burnt.
- Replace TCC solenoid (accessible in ATF pan).
- Replace torque converter if solenoid replacement fails.
Brand-specific notes (Honda)
Honda · Civic/Accord/CRV · all automatic transmission models
Symptoms
- Check engine light
- shudder at highway speed (65-75 km/h)
- poor fuel economy
- transmission not going into full lockup
- sometimes accompanied by flashing D light
Probable causes
- Failed torque converter clutch solenoid (very common Honda AT fault)
- worn torque converter
- low ATF level
- contaminated/burnt ATF
- solenoid wiring fault
Diagnostic steps
- Check ATF level and condition - burnt smell or dark color means flush needed.
- Flush ATF with Honda ATF-Z1 or DW1 (not generic Dexron).
- Replace TCC solenoid - accessible by dropping ATF pan.
- If solenoid replaced and issue persists: torque converter failure.
Cross-checked technical synthesis (QA). It does not replace the manufacturer's procedure.
Models most reported with this code (NHTSA)
Count of distinct owner complaints mentioning the code. US data — same engines, same failures.
AI here is a librarian: this page shows only what mechanics confirmed, or says “unknown”. It never suggests a diagnosis — MECCANIC interprets the code, never your car.
0 confirmed cases on P0740
Nothing confirmed yet for this code. No guess is offered on purpose.
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