Skip the auto shop - Our mechanics make house calls

P0872 OBD-II Trouble Code: Transmission Fluid Pressure Sensor/Switch C Circuit Low

diagnostic check engine light

P0872 code definition

A P0872 trouble code refers to a problem detected by the Powertrain Control Module (PCM) with the fluid pressure within the transmission. Some vehicle PCMs place the transmission into Limp-in mode in addition to storing a code and illuminating the Check Engine light. Related trouble codes include a P0870, P0871, P0873, and P0874 code.

What the P0872 code means

A P0872 trouble code means that the transmission fluid pressure has exceeded or fallen below limits set by the manufacturer.

What causes the P0872 code?

A transmission leak causing a low fluid condition is one cause of a P0872 trouble code. Additional causes include a defective high pressure pump, a malfunctioning transmission temperature sensor, an overheating engine, a slipping or malfunctioning transmission, or a faulty PCM.

What are the symptoms of the P0872 code?

Some common symptoms of a P0872 trouble code include the smell of overheated transmission fluid, sometimes accompanied by smoke. In addition to these signs, the transmission might also slip or fail to engage.

How does a mechanic diagnose the P0872 code?

To diagnose a P0872 trouble code, the mechanic needs to gather certain tools, including an OBD-II scanner, a manufacturer's wiring diagram, and a digital volt/ohmmeter. Once they have the proper tools, the mechanic can then proceed to diagnose the trouble code by taking the following steps:

  • Using the manufacturer's wiring diagram, carefully inspect the PCM wiring, connectors, and related components.
  • Examine the transmission fluid for any abnormalities or burnt smell. The mechanic should also look for any leaks.
  • If abnormalities or a burnt smell are detected, remove the transmission pan and look for any debris that might signify damage.
  • After making the necessary repairs, clear the P0872 trouble code and test the system to see if the code returns.
  • Connect the OBD-II scanner to the diagnostic connector and downloading any stored trouble codes or freeze frame data.
  • Once the necessary repairs have been made, the mechanic should fill the transmission with fluid, clear the code, and then start the vehicle, allowing it to reach a normal operating temperature. Test drive the vehicle to see if the trouble code returns.
  • Unplug the electrical connector from the transmission temperature sensor and test it for reference voltage and ground signal using the volt/ohmmeter.
  • If both are present, test the resistance of the sensor and compare it to the manufacturer's specifications.
  • The mechanic should also check the vehicle's fuses to make sure none are blown.
  • If all of the circuits and components check out, disconnect the PCM electrical connector and test the continuity and resistance between the PCM and the transmission temperature sensor.
  • Finally, the mechanic should then clear the code and re-test the system to see if the code returns.

Common mistakes when diagnosing the P0872 code

When diagnosing and repairing a P0872 trouble code, mistakes comonly made by mechanics range from fixing a transmission leak while not realizing the low fluid condition has damaged the transmission internally to rebuilding the transmission when unnecessary just because the transmission overheated.

How serious is the P0872 code?

When a vehicle PCM stores a P0872 trouble code it is important to have the problem diagnoses and fixed as soon as possible to prevent further potential transmission damage.

What repairs can fix the P0872 code?

The mechanic should make repairs to the transmission in the following order:

Need help with a P0872 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....
How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...


Related questions

Q: Trouble code P2432 - 2007 Lexus GX470

Hi - the P2432 code is an indication of low pressure from the pressure sensor. This pump is electric and may be worn out or simply needs the bearings oiled or replaced (if that is possible) - in either event,...

Q: How do I know that my OBD system is working right?

The OBD system on your vehicle is a self-monitoring system. The Powertrain Control Module monitors and controls all of the systems and functions that regulate fuel, ignition, emissions, and engine cooling as well as having some minor control over air...

Q: I have a 2003 Subaru Forester and upon starting this morning it ran fine for a minute or two. Then the Check Engine Light came on.

Too much air flowing into the intake causes the engine to lean out too much air in relation to the fuel and misfire. At an idle, the PCV valve restricts air flow, to reduce this problem. At high manifold vacuum...