P1870 on Chevrolet
Transmission Component Slipping
P1870 on Chevrolet vehicles indicates transmission component slipping. Au7o has documented this code across 1 Chevrolet model — most commonly on Avalanche. This manufacturer-specific code (common on GM and Ford automatics, e.g. 4L60E) means the computer detected slippage between transmission components, most often at the torque converter clutch, where commanded engagement does not match actual behavior. When it sets, the PCM typically raises line pressure to protect the transmission and may lock out the converter clutch. Symptoms include harsh or delayed shifts, RPM flare/slipping, and reduced fuel economy. It often points to a worn valve body bore or TCC components and should be addressed before further internal damage occurs. Typical repair costs on Chevrolet range from $1,500 to $3,500, depending on the specific model and root cause.
Common Causes of P1870
- •Worn torque converter clutch (TCC) regulator valve bore in the valve body
- •Faulty TCC solenoid or PWM solenoid
- •Worn or failing torque converter clutch
- •Low or degraded transmission fluid
- •Worn internal clutches or seals (e.g., input shaft O-ring)
- •Worn valve body / internal hydraulic leak
P1870 on Chevrolet by Model
Chevrolet Avalanche(1 issue)
- 4L60E Transmission 3-4 Clutch Failure / Slipping2002-2013
Avalanches equipped with the 4L60E automatic commonly lose 3rd and 4th gear due to 3-4 clutch pack burnout, a known factory weak point. The long fluid circuit feeding the 3-4 clutch leaks at the input housing (steel shaft galls the aluminum bore) and at the 2-4 servo, so the clutches slip, overheat, and burn. Symptoms are smooth 1-2 shifts but a flare/neutral feeling into 3rd, often with delayed engagement.
Looking for P1870 on a different make?
View P1870 across all makes →Frequently Asked Questions
What does P1870 mean on Chevrolet?▼
P1870 stands for "Transmission Component Slipping." This manufacturer-specific code (common on GM and Ford automatics, e.g. 4L60E) means the computer detected slippage between transmission components, most often at the torque converter clutch, where commanded engagement does not match actual behavior. When it sets, the PCM typically raises line pressure to protect the transmission and may lock out the converter clutch. Symptoms include harsh or delayed shifts, RPM flare/slipping, and reduced fuel economy. It often points to a worn valve body bore or TCC components and should be addressed before further internal damage occurs. On Chevrolet specifically, this code is documented across 1 model.
What causes P1870 on Chevrolet vehicles?▼
Common causes on Chevrolet: Worn torque converter clutch (TCC) regulator valve bore in the valve body, Faulty TCC solenoid or PWM solenoid, Worn or failing torque converter clutch, Low or degraded transmission fluid, Worn internal clutches or seals (e.g., input shaft O-ring). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P1870 on a Chevrolet?▼
Repair costs on Chevrolet range from $1,500 to $3,500, depending on the specific model and root cause.
Which Chevrolet models have P1870 documented?▼
Au7o has documented P1870 on 1 Chevrolet model: Avalanche.