P0871: How to Diagnose & Fix — Transmission Fluid Pressure Sensor/Switch "C" Circuit Range/Performance
4 vehicles · 4 makes · $150-$3,500 repair
How to diagnose and fix P0871: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Dodge Dart · 2013–2016
The 2.4L Dart paired with the Aisin 6-speed automatic experiences TCM failures that cause erratic shifting, failure to shift, and limp mode. The TCM mounted on the transmission is exposed to heat and vibration, leading to internal circuit board failures. Unlike the DDCT issues on 1.4T models, this affects the conventional automatic transmission.
Common Symptoms
- Transmission stuck in limp mode (2nd gear only)
- Erratic or harsh shifting
- Check engine light with transmission codes
- Transmission fails to shift into higher gears
- Delayed engagement when shifting from Park
How to Fix
Replace the TCM (Mopar 68164473AH or equivalent). The replacement TCM must be programmed with the VIN and transmission adaptation data at the dealer using wiTECH. Aftermarket remanufactured TCMs are available but must still be dealer-programmed. Cost is $600-$1,200 installed.
Sources for this issue (1)
RAM 1500 · 2013–2024
The 8-speed (ZF 8HP70 / TorqueFlite) develops a torque-converter clutch shudder felt as a vibration/judder around 30-50 mph light throttle, along with harsh downshifts, drive-engagement slam, and occasional limp mode (stuck in one gear with CEL). Root causes are degraded/aged transmission fluid and worn torque-converter clutch material, sometimes with valve-body or solenoid issues. Ram markets the trans as 'sealed/lifetime fill,' but ZF recommends fluid service every ~40-60k miles, and skipping it drives most of these complaints.
Common Symptoms
- Shudder/vibration at light throttle 30-50 mph
- Harsh or clunky downshifts
- Slam into drive/reverse
- Limp mode (stuck gear) with CEL
- Delayed or flaring shifts
How to Fix
Start with a proper fluid-and-filter service using the correct ZF 8HP fluid (many shudders clear up with fresh fluid) and apply the latest transmission software/TCM updates. If shudder persists, inspect/replace the torque converter; harsh-shift or limp events may require valve-body or solenoid repair. Adopt a 40-60k-mile fluid interval rather than the 'lifetime' claim to prevent recurrence.
Sources for this issue (2)
Chevrolet Silverado 2500HD · 2001–2019
Separate from the well-known torque converter shudder, the Allison 1000 in these trucks is documented for shift solenoid faults that drop the transmission into limp mode. The TCM sets P0700 - a generic 'transmission fault' pointer - accompanied by a specific solenoid code such as P0871 or P0872 (shift solenoid E stuck / on when commanded off). When that code sets, the transmission falls to hydraulic default, the TCM inhibits torque converter clutch engagement, and the truck is left in a single gear, usually third, sometimes refusing to move at all until it is restarted. On a loaded 2500HD this strands the truck. Forum diagnosis repeatedly finds the cause outside the solenoid itself: low or burnt fluid, a loose battery ground, or a chafed harness behind the transmission.
Common Symptoms
- Transmission stuck in one gear (limp mode)
- Check engine light with P0700
- Harsh or no shifts
- Torque converter clutch will not lock up
- Truck will not move until restarted
- Service transmission message
How to Fix
Do not open the transmission on a P0700 alone - read the sub-code first. Check fluid level and condition, then inspect the internal wiring harness pass-through connector, the transmission harness where it routes behind the case, and the battery/chassis grounds, all documented causes of these codes. If the solenoid body is genuinely at fault, the internal control solenoid body and the internal harness are replaced with the pan down. Fluid and filter service on the Allison's real interval (much shorter for tow and plow duty) is the strongest prevention. No recall covers this.
Sources for this issue (3)
Jeep Wrangler · 2012–2025
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P0871 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0871 mean?
P0871 stands for "Transmission Fluid Pressure Sensor/Switch "C" Circuit Range/Performance." This code sets when the transmission control module receives a signal from transmission fluid pressure sensor/switch C that is out of the expected range or implausible for the current conditions. This sensor monitors hydraulic pressure inside the transmission, which the module relies on to control clutch apply and shift quality. Symptoms can include harsh, delayed, or erratic shifts, slipping, or the transmission entering a failsafe mode. The cause is typically the sensor, actual fluid pressure problems, or the wiring.
What are the most common causes of P0871?
The most common causes of P0871 are: Faulty transmission fluid pressure sensor/switch C, Low or degraded transmission fluid, Internal hydraulic leak or low line pressure, Stuck or faulty pressure control solenoid, Wiring or connector issues, Valve body wear or contamination, Faulty transmission control module (less common). The specific cause varies by vehicle.
How much does it cost to fix P0871?
Repair costs for P0871 range from $150 to $3,500, depending on the vehicle and root cause.
Which vehicles are affected by P0871?
Au7o has documented P0871 across 4 vehicle models from 4 manufacturers: Chevrolet, Dodge, Jeep, RAM.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.