Faulty shift solenoid(s) (both sources). Low, old, burnt or dirty transmission fluid (OBD-Codes.com lists low and burnt fluid; RepairPal lists dirty fluid that restricts hydraulic passages). Shorted or open circuits in the transmission control wiring harness, including the part inside the transmission case (OBD-Codes.com). Faulty input or output speed sensor (OBD-Codes.com). Bad electronic pressure regulator or failed transmission pump (OBD-Codes.com). Defective valve body (RepairPal). Torque converter or torque converter lockup clutch/solenoid problems (both sources). Internal mechanical failure such as clutch failure or worn or broken parts (OBD-Codes.com). Faulty transmission range sensor or engine coolant temperature sensor (RepairPal). Defective PCM or a PCM programming error (OBD-Codes.com). The sources differ: OBD-Codes.com adds fluid level, wiring, speed sensors, the pump, pressure regulator and the PCM, while RepairPal adds the transmission range sensor, the coolant temperature sensor and the valve body.

Repair fluid leaks and refill with the correct transmission fluid. Repair damaged transmission wiring or connectors. Replace faulty shift solenoids (OBD-Codes.com says some models require the whole solenoid set to be replaced at once). Replace a faulty speed sensor, range sensor or pressure regulator when testing confirms it. Repair or rebuild the transmission, torque converter or valve body when there is mechanical failure. Repair or reprogram the PCM/TCM only after other causes are ruled out.

P0780🔧 Transmission / ShiftingStop and fix promptly

P0780: Shift Malfunction (Meaning, Causes, Fixes)

Q: What does P0780 mean?

P0780 means the computer has detected that the automatic transmission isn't shifting properly, usually because input and output shaft speeds don't match what it expects. Common causes include low or burnt transmission fluid, faulty shift solenoids, wiring problems, speed sensor faults and internal transmission wear. Automatic transmissions on OBD-II vehicles are controlled by the powertrain control module (PCM) or a separate transmission control module (TCM). The controller uses solenoids to send pressurized fluid through the valve body to change gears, and compares signals from the input and output speed sensors to check that each shift happens properly. OBD-Codes.com says P0780 is stored when the PCM detects that the transmission is not shifting properly, which can be caused by either a mechanical or an electronic fault, and that on some models it takes several drive cycles before the check engine light comes on, so it may first show as a pending code. RepairPal explains it two ways: it says the PCM sees a greater or smaller than specified RPM difference between the input shaft and output shaft, during a shift or even at steady speed (often meaning slipping or improper shifting), and it also says the PCM sets P0780 whenever the TCM stores other codes about the transmission's ability to shift. The sources word the name differently too: OBD-Codes.com calls it "Shift Malfunction", while RepairPal's title is "Shift Error". It is a generic code that only applies to automatic transmissions; OBD-Codes.com lists Ford, Honda, Mazda, Mercedes and VW among makes that use it. Because P0780 is often stored alongside more specific transmission codes, read all stored codes before deciding on a repair.

Q: Can I keep driving with P0780?

Stop and fix promptly. Treat it as urgent. Both sources agree: RepairPal rates P0780 Urgent, meaning it can cause severe damage or be unsafe, and OBD-Codes.com says it should be addressed as urgent because a minor problem can turn into a catastrophic one if it's left alone. If the transmission is slipping, shifting harshly or stuck in limp mode, drive gently, avoid highway and heavy-traffic driving, and get it checked soon.

Reviewed 2026-10-24 · Based on 2 cited source(s)

What P0780 means

Automatic transmissions on OBD-II vehicles are controlled by the powertrain control module (PCM) or a separate transmission control module (TCM). The controller uses solenoids to send pressurized fluid through the valve body to change gears, and compares signals from the input and output speed sensors to check that each shift happens properly. OBD-Codes.com says P0780 is stored when the PCM detects that the transmission is not shifting properly, which can be caused by either a mechanical or an electronic fault, and that on some models it takes several drive cycles before the check engine light comes on, so it may first show as a pending code. RepairPal explains it two ways: it says the PCM sees a greater or smaller than specified RPM difference between the input shaft and output shaft, during a shift or even at steady speed (often meaning slipping or improper shifting), and it also says the PCM sets P0780 whenever the TCM stores other codes about the transmission's ability to shift. The sources word the name differently too: OBD-Codes.com calls it "Shift Malfunction", while RepairPal's title is "Shift Error". It is a generic code that only applies to automatic transmissions; OBD-Codes.com lists Ford, Honda, Mazda, Mercedes and VW among makes that use it. Because P0780 is often stored alongside more specific transmission codes, read all stored codes before deciding on a repair.

Severity: can I keep driving?

Stop and fix promptly

Treat it as urgent. Both sources agree: RepairPal rates P0780 Urgent, meaning it can cause severe damage or be unsafe, and OBD-Codes.com says it should be addressed as urgent because a minor problem can turn into a catastrophic one if it's left alone. If the transmission is slipping, shifting harshly or stuck in limp mode, drive gently, avoid highway and heavy-traffic driving, and get it checked soon.

Common symptoms

Check engine light on (RepairPal; OBD-Codes.com says it may take several drive cycles)
Erratic, delayed or harsh shifts, or the transmission doesn't shift properly (both sources)
Transmission slipping (OBD-Codes.com)
Delayed engagement when shifting into gear (OBD-Codes.com)
Whining noise from the transmission pump (OBD-Codes.com)
Worse fuel economy (RepairPal)
Sometimes stalling when coming to a stop after highway driving, or misfire-like symptoms (RepairPal)
In unusual cases, no noticeable symptoms (RepairPal)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Faulty shift solenoid(s) (both sources)
Low, old, burnt or dirty transmission fluid (OBD-Codes.com lists low and burnt fluid; RepairPal lists dirty fluid that restricts hydraulic passages)
Shorted or open circuits in the transmission control wiring harness, including the part inside the transmission case (OBD-Codes.com)
Faulty input or output speed sensor (OBD-Codes.com)
Bad electronic pressure regulator or failed transmission pump (OBD-Codes.com)
Defective valve body (RepairPal)
Torque converter or torque converter lockup clutch/solenoid problems (both sources)
Internal mechanical failure such as clutch failure or worn or broken parts (OBD-Codes.com)
Faulty transmission range sensor or engine coolant temperature sensor (RepairPal)
Defective PCM or a PCM programming error (OBD-Codes.com)
The sources differ: OBD-Codes.com adds fluid level, wiring, speed sensors, the pump, pressure regulator and the PCM, while RepairPal adds the transmission range sensor, the coolant temperature sensor and the valve body

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Read and write down all stored codes and the freeze frame data. Other transmission codes stored with P0780 usually point to the real cause.
Check the transmission fluid level and condition. OBD-Codes.com says low fluid causes slipping, poor shifting and delayed engagement; if the fluid is more than about 2 quarts low, find and fix the leak before refilling with the recommended fluid.
If the fluid smells or looks burnt, OBD-Codes.com says to suspect internal mechanical failure that may need a rebuild.
Look for leaks at the transmission, the transmission cooler and the cooler lines.
Inspect the transmission wiring harness and connectors, especially near hot exhaust parts and sharp edges.
Clear the code and test drive to see if it comes back.

Typical fixes

Repair fluid leaks and refill with the correct transmission fluid
Repair damaged transmission wiring or connectors
Replace faulty shift solenoids (OBD-Codes.com says some models require the whole solenoid set to be replaced at once)
Replace a faulty speed sensor, range sensor or pressure regulator when testing confirms it
Repair or rebuild the transmission, torque converter or valve body when there is mechanical failure
Repair or reprogram the PCM/TCM only after other causes are ruled out

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

The transmission slips, has delayed engagement or burnt fluid, which can mean internal damage
OBD-Codes.com's diagnosis uses a scan tool, a digital volt/ohmmeter, a transmission pressure gauge to check pump pressure, and the service manual
RepairPal says P0780 can be hard to confirm: a technician compares input and output speed on a road test and watches for an RPM flare between shifts
RepairPal lists engine misfires, internal transmission problems and driveline problems as common misdiagnoses, and OBD-Codes.com notes transmissions are often rebuilt when an electrical fault was the real cause, so get a proper diagnosis before agreeing to a rebuild

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Is P0780 serious?

Yes. RepairPal rates it Urgent and OBD-Codes.com says to treat it as urgent, since a minor shifting problem can become a major transmission failure if ignored.

Can I keep driving with P0780?

Only gently and for short trips until it's checked. If the transmission is slipping or shifting harshly, avoid highway driving and get it diagnosed soon.

Does P0780 mean I need a new transmission?

Not necessarily. Low fluid, wiring problems, a shift solenoid or a sensor can set it. OBD-Codes.com warns that transmissions are often rebuilt when the real cause was electrical, so check fluid and wiring and get a proper diagnosis first.

Why is P0780 stored with other transmission codes?

RepairPal says the PCM sets P0780 when the TCM stores other codes about the transmission's ability to shift. Those more specific codes usually point to the actual fault.

How much does it cost to fix P0780?

Neither source gives a repair cost. It can range from adding fluid or fixing a wire to replacing solenoids or rebuilding the transmission, so get a diagnosis and a written estimate first.

Sources

Last reviewed 2026-10-24. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.