P1870 Code: Transmission Component Slipping
⚠️ Severe · drivable
You can drive short distances, but slipping can damage the transmission further — get it diagnosed quickly.
What P1870 means
The engine computer detected that a transmission component is slipping, most often the torque converter clutch. When the transmission can't hold the expected gear ratio or lockup, the computer stores P1870. Continuing to drive with slipping parts can cause costly internal damage.
Symptoms
- Check engine light is on
- Transmission slips or shudders
- Delayed gear engagement
- Higher engine RPM at highway speed
- Reduced fuel economy
Common causes
- most common: Worn torque converter clutch
- common: Low or dirty transmission fluid
- common: Faulty torque converter clutch solenoid
- less common: Internal transmission wear
- less common: Wiring to the transmission solenoids
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Check and replace the transmission fluid and filter | Yes | $60–150 |
| Replace the torque converter clutch solenoid | Mechanic | $150–400 |
| Replace or rebuild the torque converter | Mechanic | $500–1500 |
Frequently asked questions
Can I drive with a P1870 code?
Only short distances and with care. Slipping parts can damage the transmission badly if you keep driving, so have it diagnosed promptly.
Is a P1870 the same as a bad transmission?
Not always. It means a component is slipping, often the torque converter clutch. Sometimes a fluid change or a solenoid fixes it; other times the torque converter or transmission needs work.
How much does it cost to fix a P1870?
A fluid service is $60–$150. A torque converter clutch solenoid is $150–$400, and replacing or rebuilding the converter can run $500–$1,500 or more.
Related codes
P0741
P0741 Code: Torque Converter Clutch Circuit Performance or Stuck Off
P0740P0740 Code: Torque Converter Clutch Circuit Malfunction
P0730P0730 Code: Incorrect Gear Ratio
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.