P0712 Transmission fluid temperature sensor signal reads too low

Transmission fluid temperature sensor circuit low input

Severity not verified — if the car runs badly, have it inspected

We found no source saying how urgently P0712 needs attention. A bad temperature sensor alone is a sensor fault, but complaints pair the code with harsh cold shifting and a transmission overheating light, so we leave the rating open.

It gets more serious if:

  • Inspect soon: If the transmission overheat or "AT OIL TEMP" light comes on, or shifting is harsh, slips or the car goes into limp mode, have it inspected soon.

Source: how we rate severity

P0712 in short

P0712 means the signal from the transmission fluid temperature sensor is lower than the computer expects, which is what a short to ground or a failed sensor produces. Wiring, the sensor, or the control module are the possibilities. Some bulletins fix it by replacing the sensor, not the transmission.

The computer reads the transmission fluid temperature from a sensor, and uses it to time shifts and torque converter lock-up. P0712 sets when the voltage is lower than the sensor can legitimately give, which usually means the circuit is shorted to ground or the sensor has failed.

TroubleCodes.net lists a wiring short to ground, the sensor, and the engine or transmission computer as probable causes. Kia has a bulletin for 6-speed automatics with P0711, P0712 or P0713 that says to replace the transmission oil temperature sensor when the code is current or in history, and not to replace the transaxle.

Other makers point elsewhere: a Buick Lucerne bulletin lists P0712 with other transmission codes and tells technicians to repair and re-route the transmission wiring harnesses, and a Mitsubishi Outlander bulletin reprograms the transmission computer for P0712 and P0713. A Subaru Legacy owner says a dealer replaced the valve body for P0712 and the transmission noise stayed, so the code alone does not prove an internal fault.

Most likely causes

  1. Failed transmission fluid temperature sensor

    Supported by vehicle data
    Why it ranks here
    TroubleCodes.net lists the sensor, and Kia bulletin TRA043R2 says to replace the oil temperature sensor on 6-speed automatics when P0712 is current or in history.
    What would change this
    Rises if the sensor reading is stuck cold or implausible against a warm transmission. Falls if the reading rises normally as the fluid warms.

  2. Wiring shorted to ground, or a damaged harness

    Supported by vehicle data
    Why it ranks here
    TroubleCodes.net lists a wiring short to ground. GM bulletin SB-06-06-04-021A on the 2006-2009 Lucerne repairs and re-routes the transmission harnesses for several codes including P0712.
    What would change this
    Rises if the sensor signal wire shows continuity to ground or a harness is rubbed. Falls if the wiring tests good.

  3. Transmission computer fault or outdated software

    Possible — needs testing
    Why it ranks here
    TroubleCodes.net lists the control module. Mitsubishi bulletin 07-23-006 reprograms the transmission computer for P0712, and a Dodge Caliber owner was told to get a software update.
    What would change this
    Rises if the sensor and wiring test good, or the dealer finds a software update for your VIN. Falls if a sensor or wiring fault is found.
    How to test the transmission control module (tcm)

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read the stored codes and watch the transmission fluid temperature on a scan tool while the engine warms from cold.

    Low riskTool: scan tool with transmission live data

    • IfThe temperature reading stays very low or implausible while the transmission is warm

      It meansThe sensor or its circuit is suspect.

      Go to step 2

    • IfThe reading rises normally with warm-up

      It meansThe fault may be intermittent. Check the wiring and connectors.

      Go to step 2

    • IfOther transmission codes are stored too

      It meansDiagnose them together, since a shared harness or module fault is possible.

      Go to step 3

  2. Inspect the transmission harness and connector for rubbed insulation, corrosion or a pinched wire, and test the sensor circuit for a short to ground.

    Use cautionTool: multimeter

    Warning:Transmission parts can be hot, and you may need to work under the car. Use jack stands, let the transmission cool and disconnect the battery before touching harness connectors.

  3. Ask a dealer whether your VIN has a software update or sensor replacement bulletin for P0712.

    Low risk

Symptoms

  • Check engine light on
  • Harsh or rough shifting, mainly when the transmission is cold
  • Transmission overheat or "AT OIL TEMP" light Gets more serious: stop and have it checked.
  • Limp-home mode or slipping Gets more serious: stop and have it checked.
  • No symptoms other than the light

How to fix

  1. Ask a dealer whether a bulletin or software update applies to your VIN for P0712.

  2. With the engine off and the transmission cool, look at the visible transmission harness and connector for rubbed or corroded wiring.

Parts and cost context

  • Transmission control module (TCM):The module is rarely first. Kia says to replace the temperature sensor, not the transaxle. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Buick

  • 2006–2009 · Lucerne

    Supported by vehicle data

    GM bulletin SB-06-06-04-021A lists P0712 with other transmission codes, no start or no crank, and loss of PRNDL backlighting, and prescribes repairing and re-routing the transmission wiring harnesses. Whether the bulletin is still current is not verified.

  • SB-06-06-04-021AStatus unverified

    Check engine light, no start/crank, PRNDL backlighting loss, P0712 and other codes

    2006–2009lucerne · issued · NHTSA 10032193

    Lists P2761, P0712, P0713, P0716, P0717 and/or P0748 and tells technicians to repair and re-route the transmission wiring harnesses.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Mitsubishi

  • 2007 · Outlander

    Supported by vehicle data

    Mitsubishi bulletin 07-23-006 reprograms the transmission control module for P0712 and P0713 on the 2007 Outlander. Whether the bulletin is still current is not verified.

  • 0723006Status unverified

    TCM reprogramming for P0712, P0713, service required with no MIL

    2007outlander · issued · NHTSA 10022412

    Reprograms the transmission control module for P0712 and P0713 when SERVICE REQUIRED is displayed with no check engine light.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Subaru

  • 2016 · Legacy

    Possible — needs testing

    An NHTSA complaint on a 2016 Legacy says a dealer replaced the valve body for P0712 after an "AT OIL TEMP" light and slipping, and the transmission still made loud noises. Owner report only.

Dodge

  • 2009 · Caliber

    Possible — needs testing

    An NHTSA complaint on a 2009 Caliber lists P0712 with several other transmission codes; a shop suggested a transmission computer software update and the codes returned after clearing. Owner report only.

  • P0711Transmission fluid temperature reading does not make sense

    Same system Supported by vehicle data

    Kia TSB TRA043R2 covers P0711, P0712 and P0713 together for the transmission temperature sensor, so check all three.

  • P0713Transmission fluid temperature sensor A circuit, high input

    Same system Supported by vehicle data

    Kia bulletin TRA043R2 and Mitsubishi bulletin 07-23-006 both list P0713 with P0712, the high-input counterpart.

  • P0717No signal from the transmission input or turbine speed sensor

    Shares causes Supported by vehicle data

    GM bulletin SB-06-06-04-021A lists P0712 and P0717 together for a damaged transmission harness on the 2006-2009 Lucerne.

All Transmission codes

P0712 questions

What does P0712 mean?

The transmission fluid temperature sensor circuit is sending a signal that is lower than the computer expects, usually from a short to ground or a failed sensor.

Does P0712 mean the transmission is failing?

Not necessarily. The code is about the sensor circuit. Kia says to replace the temperature sensor and not the transaxle, and a Subaru owner found noises remained after a valve body replacement.

Sources and review

  1. P0712 - Transmission fluid temperature sensor - low input — TroubleCodes.net
  2. NHTSA complaint 11497377: 2016 Subaru Legacy — NHTSA Office of Defects Investigation
  3. NHTSA complaint 11085068: 2009 Dodge Caliber — NHTSA Office of Defects Investigation
  4. Kia TSB TRA043R2 (NHTSA 10090166) — Kia Motors America ,
  5. GM bulletin SB-06-06-04-021A (NHTSA 10032193) — General Motors ,
  6. Mitsubishi bulletin 07-23-006 (NHTSA 10022412) — Mitsubishi Motors North America ,
Last reviewed
Written by
Saurabh K.
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