A failed 4L80E TCC solenoid kills lockup, kills your MPG, and throws P0741. Fix is straightforward if you catch it early.
Symptoms
- P0741 TCC stuck off (most common)
- P0740 TCC circuit
- Higher highway RPM at cruise
- MPG drop 2-4 MPG
- No converter lockup feel
- Sometimes erratic torque converter shudder
How the TCC solenoid works
- PWM-controlled by the PCM
- Routes pressure to the TCC apply circuit
- Coil resistance spec: 20-30 ohms
- Wear part - typically fails between 100k-180k miles
Diagnosis
Step 1: Pull DTCs
- P0741 confirms TCC stuck off
- P0742 confirms TCC stuck on (different problem)
Step 2: Check fluid
- Burnt fluid = converter clutch worn, not solenoid
- Clean fluid + P0741 = solenoid first suspect
Step 3: Resistance test
- Drop pan
- Disconnect solenoid wiring
- Ohm across terminals: 20-30 = good, infinite = open coil
Step 4: Check ground / PCM
- Backprobe ground wire with key on
- Should toggle when PCM commands lockup
- Bad ground = wiring, not solenoid
Replacement parts
Solenoid:
- AC Delco 24202375 (OEM)
- TransGo TCC-A (HD aftermarket)
- $25-$60 part
Always replace together:
- Pan gasket
- Filter
- 7+ quarts Dexron VI
Install
- Drain pan, drop pan
- Disconnect solenoid wiring connector
- Remove 2 valve body bolts holding TCC solenoid bracket
- Pull solenoid, insert new with new O-ring
- Reverse for reinstall
- Torque pan bolts in spec sequence (97 in-lb)
Total time and cost
DIY:
- Time: 2-3 hours
- Parts: $80-$150 (solenoid, gasket, filter, fluid)
- Code reset after install
Shop:
- Labor: $250-$450
- Parts: $80-$150
- Total: $330-$600
When solenoid is not the fix
If P0741 returns after a new solenoid, the problem is upstream:
- TCC apply piston / clutch worn
- Valve body wear (TCC regulator stuck)
- PCM ground or driver fault
Need a 4L80E TCC solenoid, full solenoid kit, or torque converter? Shop our 4L80E catalog. OEM solenoids, complete solenoid kits, HD converters. Free shipping over $70.
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