Question 1

What does P1870 mean?

Accepted Answer

P1870 - Transmission Component Slipping (GM). GM-specific: Internal transmission component is slipping beyond acceptable limits. Often the TCC or 3-4 clutch pack.

Question 2

What are the symptoms of P1870?

Accepted Answer

TCC slip on highway, RPM flutters at cruise speed, Harsh shifts, Check engine light

Question 3

What causes P1870?

Accepted Answer

TCC apply valve bore worn, 3-4 clutch pack failure, Solenoid body ball capsule leaking, Low line pressure, Contaminated fluid

Question 4

How much does it cost to fix P1870?

Accepted Answer

Typical repair cost: $500-$3,500. On GM 4L60E transmissions, P1870 is one of the most common transmission codes. It usually means the TCC apply valve bore in the valve body has worn and isn't directing enough pressure to the TCC. A valve body resleeve or replacement is the proper fix. A band-aid is to install a corvette servo.

P1870 — Transmission Component Slipping (GM)

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Common symptoms of P1870

Common causes of P1870

Repair cost & difficulty

Vehicles commonly affected

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