99 Dodge Stratus P0740 Code: Torque Converter Clutch Solenoid Circuit Issue and Diagnosis

If your transmission is a 41TE type, P0740 means the Torque Converter Clutch (TCC) solenoid circuit is open — TCC is not a gear but part of the transmission's locking mechanism. Start with basic circuit checks using a DVOM. The 'solenoid pack' often includes multiple solenoids and is typically replaced as a unit.

I don't know what model transmission my 1999 Dodge Stratus has — can you help me identify it? I've had the shift solenoid replaced three times in two years. How do I perform circuit checks using a multimeter or DVOM? Any guidance would be appreciated.

A structured troubleshooting approach — including wiring diagrams and a digital volt-ohm meter (DVOM) — is essential for diagnosing this issue. Your comment that you don't know the transmission model suggests it may be best to consult a professional mechanic.

Sorry, I meant I don’t know what transmission model my car has — not that I’m joking about it!

There are no other diagnostic codes. The vehicle runs fine under normal conditions. I’ve checked the temperature gauge and speedometer — everything works normally. Only issue is inability to shift into overdrive. I'm having trouble finding official wiring diagrams — will keep searching when time permits.

Only P0740 code present; car drives fine under all conditions, no issues with engine performance or instrument cluster. The problem is specifically that it won’t go into the highest gear (overdrive).

For a non-DIY user, here's how to properly diagnose P0740: Using a scan tool, check the number of times the code has set. If it’s three or fewer trips, proceed to step 3; if more than three, move to next step. Record all DTCs and one trip failure. Erase codes using the scan tool. With the transmission at normal operating temperature, drive in 4th gear at light throttle (50 MPH) for 17–20 seconds. The scan tool should show either partial or full lock-up (PEMCC/FEMCC). Gradually increase throttle — a transition from PEMCC to FEMCC should occur within 5–10 seconds. Repeat this process two more times. If P0740 is still present, proceed; if not, go to step 8. Step 3: Connect a 0–300 psi (21 kg/cm²) pressure gauge to the TCC OFF test port. Using the scan tool, record and erase DTCs as per manufacturer instructions. Drive in overdrive until transmission reaches normal operating temperature. Step 4: At speeds above 50 MPH, release throttle and tip-in to about 1/4 throttle (25–29 degrees) and hold for 10 seconds. Repeat three times while monitoring the scan tool and pressure gauge. If a PEMCC-to-FEMCC transition occurs during any of these attempts, conditions for setting P0740 are not present — go to step 8. If no transition occurs, proceed. Step 5: If the pressure gauge reads less than 10 psi (0.7 kg/cm²) during step 4, inspect and repair the oil pump bushing. Always replace the torque converter if P0740 is set without a P1784 code. Clean the transmission and oil cooler thoroughly. Step 6: If P1784 was present before erasing codes, replace the transmission solenoid pack. Otherwise, proceed. Step 7: While driving, come to a stop and shift into Neutral. Monitor the L-R pressure switch with the scan tool. If it shows 'CLOSED', replace the valve body. If not, replace the solenoid pack. Step 8: Inspect for loose terminals or faulty connections: - Engine ground - TCM ground - TCM battery feed - TCM fused ignition output circuit - Power feed to transmission control relay Repair as needed. If previous steps fail, erase codes and perform VER-1A verification test. If the transaxle still doesn’t function correctly, inspect battery voltage — low voltage can cause non-DTC symptoms. Ensure the battery is fully charged and correct any issues before final testing.

Thanks for the detailed explanation — really helpful!