P0846: How to Diagnose & Fix — Transmission Fluid Pressure Sensor/Switch "B" Circuit Range/Performance
3 vehicles · 3 makes · $350-$2,800 repair
How to diagnose and fix P0846: 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.
Hyundai Venue · 2020–2026
Hyundai TSB 23-AT-010H (August 2023) covers 2020MY-and-later Venue (QX) equipped with the IVT, alongside Elantra, Accent and Kona IVT models. The IVT driven-pulley oil pressure sensor (part 48885-02300) can fail electrically or read out of range, turning on the check-engine light with P0845 (sensor output at or below 0.27 V or at or above 4.50 V), P0846 (sensor output 2.5-3.5 V with target-vs-actual driven-pulley pressure off by 4 bar or more) or P0867 (target vs actual secondary pulley pressure differing by more than 7 bar). The bulletin exists because dealers had been replacing whole transmissions for what is a sensor fault: when the vehicle has ONLY the DTC and no drivability complaint (no slipping, shift shock, poor acceleration or failure to engage), the sensor is replaced through the IVT oil pan with a new pan gasket and 7 quarts of fluid, then 'Oil Pressure Characteristics Input' and adaptive-value relearn are performed with GDS-M. If drivability symptoms are present the whole IVT is still replaced. Note P0867 also appears in the T8X campaign list for 2020-22 units, so an owner with P0867 should have both bulletins checked.
Common Symptoms
- Check engine light with the car driving normally
- Stored P0845, P0846 or P0867 in the transmission control unit
- Slipping, shift shock or poor acceleration (means the IVT is replaced, not just the sensor)
How to Fix
Have the dealer scan the TCU. If only P0845/P0846/P0867 are stored and the car drives normally, TSB 23-AT-010H authorises replacing the IVT oil pressure sensor (48885-02300), IVT pan gasket (48282-2H000), plug gaskets and fluid, followed by the GDS oil-pressure characteristics input and adaptive learning - subject to actual warranty eligibility. The US 10-year/100,000-mile powertrain warranty generally applies to the original owner; subsequent owners normally retain 5-year/60,000-mile new-vehicle coverage, subject to its terms. Ask the dealer to verify coverage for the diagnosed part. If slipping or shift shock accompanies the code, the transmission itself is replaced.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Sources for this issue (2)
Jeep Liberty · 2003–2012
The 42RLE four-speed automatic used behind the 3.7L V6 develops solenoid-pack and pressure-sensor faults that produce delayed or abandoned upshifts, harsh 2-3 shifts, slipping, and limp mode locked in second gear. The characteristic codes reported by owners are P0755 (2/4 shift solenoid) and P0846 (transmission fluid pressure sensor/switch B range-performance), the latter almost always chased to the solenoid/pressure-sensor pack. The forum record also carries an important diagnostic caveat: P0846 has returned after a new solenoid pack, even after two pack replacements, and owners advise confirming the wiring is intact before buying another pack, so a second solenoid pack is often the wrong answer. Fluid neglect accelerates all of it - the 42RLE is intolerant of burnt or low ATF.
Common Symptoms
- Delayed or missing upshift
- Harsh or banging 2-3 shift
- Stuck in second gear (limp mode)
- Slipping under load
- Check engine light with transmission codes
- Shift quality changes when hitting bumps (harness chafe)
How to Fix
Diagnose before parts: check fluid level and condition, scan for the exact code, then inspect the transmission harness where it passes between the body and chassis for crush damage and check valve body bolt torque. Where the solenoid/pressure-sensor pack is genuinely at fault, it is replaced through the pan with the transmission in the vehicle - a moderate job, not a rebuild. Use only ATF+4; the wrong fluid causes shudder and accelerates solenoid wear. Persistent slipping after a good solenoid pack points to the valve body or to internal clutch wear, which is a rebuild. No recall covers this.
Sources for this issue (3)
CUPRA Leon · 2018–2018
The 2018 Leon Mk3 Cupra (hatch and ST) built before the mid-2018 switch to petrol particulate filters (the "pre-GPF" cars) uses the 6-speed wet-clutch DQ250 DSG. Cars registered from late 2018 got the 7-speed DQ381 instead. Owners on the SEAT Cupra forum rate the DQ250 well, and it is a different gearbox from the dry-clutch DQ200 7-speed in lower-powered VW Group cars. When a DQ250 does go wrong, specialists say the mechatronic unit is usually to blame rather than the clutches. This unit bolts onto the gearbox and holds the control electronics, solenoids, pressure sensors, a pressure accumulator and the hydraulic plate, and it sets the pressure for both clutches. Old or contaminated fluid, clutch-wear debris blocking the valve screens, worn solenoids and high oil temperatures can all upset that pressure control. The problems usually show up once the gearbox is fully warm. Typical stored codes in the transmission module include P0841 and P0871 (pressure sensor range), P17BF (implausible shift pressure), P189C (implausible clutch 2 pressure) and P0717 (input speed sensor).
Common Symptoms
- Shifts get harsh or jerky once the gearbox is fully warm, especially from 1st to 2nd
- Engagement into Drive or Reverse is delayed
- The PRNDS display flashes and the gearbox drops into neutral
- The gearbox goes into limp mode and only offers some gears (for example 2nd, 4th and reverse)
- The gearbox sometimes refuses to change gear
How to Fix
1. Start by reading the fault memory in the transmission module (address 02). Note each code and whether it is stored or intermittent. A pressure code such as P0841 can mean a sensor reading is off after the fluid has broken down or become contaminated, so it does not prove the whole mechatronic unit has failed. 2. Check the fluid level and condition. Dark or burnt-smelling fluid points to overheating. Ask whether the DSG service has been done: specialists recommend fresh fluid and a new filter every 60,000 km. 3. A specialist can log clutch 1 and clutch 2 pressures, shift times and oil temperature on a drive, run the clutch actuator tests and do a pressure-hold test on the accumulator. This shows whether the fault is a single sensor or solenoid, or the whole unit. 4. Many DQ250 faults clear up after a fluid and filter service, a solenoid test, clutch adaptations and a software update. If they don't, the mechanic can repair the mechatronic unit or swap it for a remanufactured one. A complete gearbox replacement is rarely needed. 5. None of the cited sources mention a recall, service bulletin or extended warranty for this gearbox on the Leon. Once the factory warranty has run out, the owner normally pays for the repair. Cost (US parts and labour, generic DQ250 figures): about $400–$800 for a fluid and filter service and about $1,400–$2,800 to repair or exchange the mechatronic unit.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine VW DQ250 DSG transmission filter kit with six litres fluid
perform a due DQ250 fluid-and-filter service after diagnosis and before condemning the mechatronic Fitment/availability: Confirmed DQ250/02E/0D9 six-speed wet-clutch gearbox only; kit includes genuine filter 02E305051C, six litres G05218…
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Sources for this issue (4)
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P0846 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 P0846 mean?
P0846 stands for "Transmission Fluid Pressure Sensor/Switch "B" Circuit Range/Performance." This code means the transmission control module sees a signal from transmission fluid pressure sensor/switch B that is present but outside the expected (range/performance) values for current operating conditions. This sensor reports hydraulic pressure used to apply clutches and control shifts, so an implausible reading affects shift control. Symptoms can include harsh or delayed shifts, slipping, or the transmission entering failsafe mode. The fault is usually with the sensor, fluid pressure itself, or wiring rather than a total electrical failure.
What are the most common causes of P0846?
The most common causes of P0846 are: Faulty transmission fluid pressure sensor/switch B, Low or dirty transmission fluid, Internal hydraulic leak or low line pressure, Stuck or faulty pressure control solenoid, Wiring or connector problems, Valve body wear, Faulty transmission control module (less common). The specific cause varies by vehicle.
How much does it cost to fix P0846?
Repair costs for P0846 range from $350 to $2,800, depending on the vehicle and root cause.
Which vehicles are affected by P0846?
Au7o has documented P0846 across 3 vehicle models from 3 manufacturers: CUPRA, Hyundai, Jeep.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.