DTC code
P1740
Torque Converter Clutch Inductive Signature Malfunction
Technical guide
Symptoms
- Check Engine light on
- erratic shifting
- transmission slipping
- torque converter shudder/judder (well documented on Honda/Acura)
- engine stalling when coming to a stop
- poor fuel economy.
Probable causes
- 1) Faulty torque converter clutch (TCC) solenoid. 2) Faulty overdrive solenoid. 3) Low
- overheated or contaminated transmission fluid preventing proper clutch apply. 4) Wiring or connector issues in the TCC/overdrive solenoid circuit. 5) Damaged torque converter.
Diagnostic steps
- Retrieve the code and freeze frame data with a scan tool and confirm the make-specific definition.
- Check transmission fluid level and condition first — low, burnt or contaminated fluid is a common root cause; if the fluid is at fault, service it and re-test (on Honda/Acura with TCC judder, sources recommend a triple drain-and-fill with genuine Honda ATF-DW1).
- Visually inspect the TCC/overdrive solenoid wiring and connectors for damage or poor connections.
- Test the TCC and overdrive solenoids (command them with a scan tool and verify operation/resistance per spec).
- Road-test while monitoring TCC apply on live data — verify whether engine RPM drops when lockup is commanded.
- If solenoids and wiring test good and shudder persists, suspect the torque converter itself. High severity — diagnose as soon as possible.
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 P1740
Nothing confirmed yet for this code. No guess is offered on purpose.
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