P0933 on 2010-2018 Ram 2500 6.7L Cummins: Hydraulic Pressure Sensor Causes and Fixes

What's Unique About the 2010-2018 Ram 2500

This code is extremely common on the Chrysler 68RFE automatic transmission paired with the 6.7L Cummins engine. The issue is almost always a failure of the line pressure sensor, also known as a transducer. While the sensor can sometimes be replaced individually, it is integrated into the main solenoid pack (or block). The most reliable, long-term repair is to replace the entire solenoid pack with a genuine Mopar part, as aftermarket or 'clone' sensors are known to fail prematurely or be faulty out of the box.

Generation note: This range covers the end of the third generation (2010) and the entire fourth generation (2011-2018) Ram 2500. Both generations used the 6.7L Cummins engine paired with the 68RFE transmission, and this P0933 fault is common to the transmission itself across this entire period.

Symptoms You May Notice

• Check Engine Light is on
• Transmission is stuck in one gear (limp mode), often 3rd or 4th
• Harsh, erratic, or delayed gear shifts
• Vehicle may not move forward from a stop until manually shifted
• With a scan tool, the line pressure reading is stuck at a high value (e.g., 252 psi) at startup

Most Likely Causes

1. Faulty Hydraulic Pressure Sensor (Transducer) 🔴 High Probability The line pressure sensor on the 68RFE is a known failure point. It is part of the solenoid pack assembly, which is a widely documented weak point.
   How to confirm: Use a scan tool to monitor live data. Compare 'Desired Line Pressure' to 'Actual Line Pressure'. If the actual pressure is stuck high (e.g., 252 psi) and does not change with RPM, the sensor has failed. A 2015 Ram owner on Turbo Diesel Register confirmed this exact symptom before fixing the issue by replacing the solenoid pack.
   Typical fix: Replace the entire transmission solenoid pack. Also replace the transmission fluid and both internal filters (sump and spin-on) at the same time.
   Est. part cost: $400-$600 for an OEM solenoid pack
2. Low or Burnt Transmission Fluid ⚪ Low Probability The 68RFE is sensitive to fluid level. A user on a Ram forum reported getting pressure codes P0933 and P0871 after a fluid change because the level was too low.
   How to confirm: Check the transmission fluid level and condition using the dipstick. The fluid should be at the correct level, red in color, and not have a burnt smell.
   Typical fix: Perform a transmission fluid and filter service using the correct Mopar ATF+4 fluid.
   Est. part cost: $100-$200
3. Wiring or Connector Issue ⚪ Low Probability The main transmission electrical connector is exposed to the elements. TSB 21-016-17 specifically addresses diagnosing water intrusion and corrosion at this 16-way connector, which can cause this code. A poorly seated connector can also cause false high-pressure readings.
   How to confirm: Disconnect and inspect the main round connector at the driver's side of the transmission case for corrosion, moisture, or spread/damaged pins. Check for proper pin drag.
   Typical fix: Clean the connector pins with electrical contact cleaner or repair/replace the damaged harness section.
   Est. part cost: $10-$300

Rare But Worth Checking

• Faulty Transmission Control Module (TCM) or Powertrain Control Module (PCM): This is very rare. The sensor and wiring should be ruled out completely before condemning the control module. A Reddit user with a 2018 Ram reported still having the code after replacing all transmission components, pointing towards a rare wiring or module issue.
• Internal Mechanical Transmission Failure: In some cases, a mechanical failure like a failed clutch or pump issue can cause pressure problems, but this is usually accompanied by other symptoms and codes.

Diagnosis Steps

1. Connect a high-quality OBD-II scanner capable of reading transmission live data.
2. Record and check for any other transmission-related codes, particularly P0869, P0934, and P0935.
3. Access the live data stream for the transmission.
4. With the engine running at idle in Park, observe the 'Desired Line Pressure' and 'Actual Line Pressure' values.
5. A healthy system will show both values being very close. A classic symptom of a failed sensor is the 'Actual Line Pressure' reading a fixed high value, such as 252 psi, from the moment the engine starts.
6. If the reading is stuck high, the pressure sensor is almost certainly faulty.
7. If the readings seem plausible, check the transmission fluid level and condition. Ensure it is full and not burnt.
8. Inspect the main transmission electrical connector on the driver's side for any signs of corrosion, moisture, or damaged pins, as noted in TSB 21-016-17.
9. If all other checks pass, the most likely cause remains the hydraulic pressure sensor, which is best replaced as part of the solenoid pack assembly.

Parts You'll Likely Need

• Transmission Solenoid Pack (Block) (OEM #68376695AB) — This assembly contains the hydraulic pressure sensor (transducer) that is the primary cause of code P0933. This is the most current part number for models with a gray connector and supersedes 68376695AA and 68353383AB. Replacing the whole pack is the most reliable fix.
  Trusted brands: Mopar, Revmax, SunCoast
  OEM price range: $400-$600
  Aftermarket price range: $250-$450
• Line Pressure Sensor (Individual) (OEM #4799758AD) — In some cases, only the individual sensor is replaced. While less common and potentially less reliable than replacing the entire pack, it is a documented repair that has solved the P0933 and P0868 codes for some owners.
  Trusted brands: Mopar, Wells
  OEM price range: $50-$100
  Aftermarket price range: $30-$60
• Transmission Filter Kit (Sump and Spin-on) (OEM #5013470AE (Sump), 5015267AD (Spin-on)) — These should always be replaced when the transmission pan is removed for service.
  Trusted brands: Mopar, Wix, ATP
  OEM price range: $50-$80
  Aftermarket price range: $30-$60
• Mopar ATF+4 Automatic Transmission Fluid — The transmission must be refilled with the correct fluid after replacing the solenoid pack. A typical service requires 7-9 quarts.
  Trusted brands: Mopar
  OEM price range: $10-$15 per quart
  Aftermarket price range: $8-$12 per quart

Related Codes That Often Appear With This One

• P0869 — This code for 'Line Pressure High' is often triggered because the faulty P0933 sensor is sending an erroneously high pressure reading to the TCM.
• P0934 — This code for 'Line Pressure Sensor Circuit Low' can appear with P0933 if the sensor is failing intermittently, causing the signal to fluctuate wildly.
• P0935 — This code for 'Line Pressure Sensor Circuit High' often appears alongside P0933, as a stuck-high sensor reading can trigger both a performance fault and a circuit-high fault.

Technical Service Bulletins (TSBs) & Recalls

• TSB 21-016-17: Details diagnostic procedures for water intrusion and corrosion at the 16-way transmission electrical connector, which can be a direct cause of P0933.
• TSB 18-069-25: Notes a link between P0933, P0868 (Line Pressure Low), and subsequent gear ratio error codes, pointing to the pressure sensor fault as the root cause.
• TSB 18-091-16 / 18-057-15 REV A: Both list P0933 as a potential Diagnostic Trouble Code related to transmission performance and diagnostics.

Platform-Specific Known Issues

• Solenoid Connector Color: The solenoid pack for 2010-2018 models uses a gray or white electrical connector. Starting in 2019, the 68RFE was updated to use a pack with a blue connector that is electronically coded to the vehicle and is not interchangeable with earlier models.

Mechanic-Grade Diagnostic Values

• Line Pressure Sensor (LPS) operating voltage — expected: 0.35 to 4.75 volts. Failure: Voltage outside this range will set a P0934 (low) or P0935 (high) circuit code. A stuck voltage reading indicates a failed sensor.
• Pressure Control Solenoid (PCS) resistance — expected: 4.3 - 4.9 Ohms. Failure: Resistance outside this range indicates a faulty solenoid coil.
• Pressure Control Solenoid (PCS) circuit current draw — expected: Up to 1 Amp (maximum commanded current). Failure: Inability to draw ~1 Amp when commanded by a scan tool suggests a problem in the wiring, PCM driver, or the solenoid itself.
• Line Pressure Duty Cycle % at idle — expected: 22% to 24%. Failure: A duty cycle consistently at 5% indicates the computer is maxing out its command to lower pressure, pointing to a mechanical or hydraulic issue.
• Line Pressure Sensor Signal and Sensor Ground circuit resistance — expected: Below 5.0 Ohms. Failure: Resistance above 5.0 Ohms indicates an open or high-resistance in the wiring harness between the PCM and the transmission connector.

Scan Tool Commands That Help

• wiTECH, Snap-on, AutoEnginuity: Quick Learn — This procedure is mandatory after replacing the solenoid pack or valve body. It allows the TCM to learn the hydraulic characteristics of the new components and establish baseline clutch volume indexes (CVIs). Failure to perform a Quick Learn will result in poor shift quality and can cause premature transmission wear.
• wiTECH or equivalent: Line Pressure Actuation Test — Using a special tool (Miller #8333 Transmission Simulator), a technician can command specific line pressures and verify if the scan tool readings match the commanded state. This helps isolate a faulty sensor from a wiring or PCM issue.

Wiring & Ground Locations

• Solenoid/TRS Assembly Connector (C107) — Main round 16-pin connector on the driver's side of the transmission case.. This is the primary connection for the entire solenoid pack, including the line pressure sensor. Corrosion (often hidden under the yellow cap), spread pins, or a poorly seated connection here is a common cause of P0933 and related codes.
• Pin 12 (Solenoid/TRS Connector) — Pin 12 on the main round transmission connector.. This is the Pressure Control Solenoid (PCS) control circuit. Testing current draw on this wire can verify the integrity of the solenoid coil and the PCM's driver circuit.
• Pin T38 (PCM Connector) — This is the Line Pressure Sensor Signal circuit pin at the Powertrain Control Module (PCM).. Testing for continuity and resistance on this circuit between the PCM and the transmission connector can identify an open or shorted wire in the main harness.
• Pin T160 (PCM Connector) — This is the Sensor Ground circuit pin at the Powertrain Control Module (PCM).. A high-resistance or open ground on this circuit can cause the sensor to send an erroneously high voltage signal, triggering P0933 and P0935.

Real Owner Repair Stories

• YouTube channel 'OCD AUTO' (2013 Ram w/ 6.7L Cummins) — P0933 code would set immediately when revving the engine. Scan tool showed actual line pressure was much higher than desired, and the PCM was maxing out the duty cycle trying to lower it.
  ❌ Tried (didn't work) The transmission had already been replaced, but the code persisted., Technician verified pin tension at the main connector was good., Verified the Pressure Control Solenoid circuit could draw a full 1 amp of current, ruling out a wiring/PCM driver issue.
  ✅ What actually fixed it The replacement transmission was new but came with a faulty, cheap 'clone' line pressure sensor. Replacing only the individual sensor with a quality aftermarket (Wells) part resolved the issue. The faulty sensor was not reading pressure accurately.
• Reddit user u/thesose67 (2018 Ram 2500 w/ 6.7L Cummins) — Persistent P0933 code, which would be accompanied by P0935 if the truck was restarted without clearing codes.
  ❌ Tried (didn't work) Replaced valve body with an ATS performance unit., Replaced individual sensors., Replaced the entire shift solenoid with a Revmax unit., Installed a deep pan and thermal bypass., Checked wiring at the main solenoid harness.
  ✅ What actually fixed it The user's post is a diagnostic journey without a final confirmed fix, but it highlights a critical scenario where replacing all common components (valve body, solenoid pack, sensors) with aftermarket parts did not solve the problem, pointing strongly to a hard-to-find wiring harness issue or a rare PCM fault.

OEM Part Supersession History

• 68376695AA → 68376695AB — Standard part number revision by Mopar for the gray connector solenoid pack.
  Heads up: Both 68376695AA and 68376695AB are for 2010-2018 models with a gray or white connector. They are not compatible with 2019+ models that use a blue, electronically-coded connector.
• 52120000AA → 68376695AB — Older part number that was replaced by the updated gray connector design.
  Heads up: 68376695AB is the correct service replacement.

Model Year Variations Within This Range

• 2010: Early 2010 models may still use the white connector solenoid pack from the earlier 68RFE design. Around 2011, the gray connector solenoid pack became standard. While the white connector solenoid can service all models up to 2018, the gray connector pack cannot be retrofitted to earlier transmissions designed for the black connector (pre-2004).

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Front End "Death Wobble" 🔴 High — Common, especially on trucks with higher mileage, larger tires, or worn suspension components. Can be triggered by hitting a bump at highway speeds. (Ref: No specific recall, but it is a widely acknowledged issue. The primary cause is typically a worn track bar, but can also involve ball joints, tie rod ends, and steering dampers.)
• EGR System Clogging and Failure 🟠 Medium — Very common. The 6.7L Cummins produces significant soot, which clogs the EGR valve and cooler. Cleaning is recommended every ~67,500 miles to prevent issues. Failure can lead to performance loss, coolant leaks, and overheating. (Ref: TSB #18-012-12 REV. A was issued for some models to address related codes with a software update, but hardware failure is the most common problem.)
• VGT Turbo Actuator Failure / Stuck Vanes 🔴 High — A very common failure point on the Holset VGT turbo. The electronic actuator fails or the variable vanes inside the turbo get stuck with carbon buildup ('Stuck Turbo Syndrome'). This leads to a loss of power, poor throttle response, excessive smoke, and loss of the exhaust brake function.
• Radiator Leaks (Plastic End Tanks) 🟠 Medium — Failures of the plastic end tank seams are common, especially on trucks used for towing or that experience frequent heat cycles. Often starts as a slow coolant loss with no visible puddle before becoming a major leak.
• Aftertreatment System Failures (DPF, SCR, DEF) 🔴 High — The emissions system is a frequent source of expensive repairs. Failures include clogged Diesel Particulate Filters (DPF), failed SCR canisters, faulty NOx sensors, and DEF pump/header issues. These repairs can cost thousands of dollars.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For this specific P0933 repair, buying a used solenoid pack from a junkyard is generally not recommended. The line pressure sensor within the pack is a known high-failure item, and a used part carries a significant risk of having the same fault or failing shortly after installation. The labor involved in accessing the part is substantial, making it unwise to risk a repeat repair with a part of unknown history.

Donor-vehicle mileage cap: roughly under 60000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Verify the connector color (must be gray or white for this year range).
• Inspect the connector pins for any signs of corrosion, damage, or being bent.
• If possible, get the VIN of the donor vehicle to confirm it's from a 2010-2018 model.
• Avoid parts from vehicles that show signs of flood damage or have been in a severe accident that could have impacted the transmission.

OEM-only on this vehicle (don't cheap out):

• Transmission Solenoid Pack (Block)

Aftermarket brands forum-validated for this vehicle:

• Revmax (Often cited in forums as a quality remanufacturer/upgrader)
• SunCoast (Known for performance and heavy-duty rebuild components)
• Sonnax (Provides high-quality individual components and valve body upgrades, though not a complete solenoid pack)

Brands owners have reported issues with on this vehicle:

• Unbranded 'clone' or 'no-name' parts from online marketplaces (e.g., Amazon, eBay). These are frequently reported by technicians and owners to be defective out of the box or fail very quickly, as documented in multiple diagnostic videos and forum posts.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0869 — A direct companion code for 'Transmission Fluid Pressure High'. The faulty sensor that causes P0933 sends a false high-pressure reading, triggering both codes simultaneously.
• P0935 — Indicates 'Hydraulic Pressure Sensor Circuit High'. This code is often logged alongside P0933 as part of the same sensor failure event, as documented in owner reports.
• P0934 — Indicates 'Hydraulic Pressure Sensor Circuit Low'. This points to a fault in the same sensor circuit as P0933 and can be caused by a wiring issue or a different failure mode of the sensor.
• P0868 — Indicates 'Line Pressure Low'. TSB 18-069-25 notes a link between P0933 and P0868, suggesting that an erratic sensor can send both high and low signals, causing multiple pressure-related codes.
• P0871 — Can appear with P0933 when the root cause is low transmission fluid. The incorrect fluid level can cause erratic pressure readings across multiple circuits.

Frequently Asked Questions