P2706 on 2018-2020 Ram 3500: MS Solenoid Circuit Causes and Fixes

What's Unique About the 2018-2020 Ram 3500

The 68RFE automatic transmission, used in Ram Heavy Duty trucks for many years, has a well-documented history of solenoid pack failures, making P2706 a common code. The 2018-2020 model years are particularly notable because they span a critical part change. 2018 models use a solenoid pack with a grey or white connector, while 2019 and newer models use an updated pack with a blue connector; the parts are not interchangeable. Furthermore, for 2019+ models, a specific 46-character code from the new solenoid must be programmed into the TCM, making the repair more complex.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: The 2018 model year is the last of the fourth-generation Ram HD, while 2019-2020 models are the fifth generation. This change affects the transmission solenoid pack. 2018 models use a pack with a grey/white connector (e.g., Mopar P/N 68353383AB), while 2019+ models use a pack with a blue connector (e.g., Mopar P/N 68456067AA). They are not interchangeable.

Symptoms You May Notice

• Check Engine Light is on
• Harsh, erratic, or delayed gear shifts
• Transmission gets stuck in one gear (limp mode), often 3rd or 4th
• Vehicle may not move from a stop, or has a long delay before engaging Drive
• Loud buzzing sound from the transmission in Park or Neutral when limp mode is active

Most Likely Causes

1. Failed Transmission Solenoid Pack 🔴 High Probability The 68RFE solenoid pack is a widely known failure item due to internal electronic components (like coil wires) breaking down from heat, vibration, and fluid contamination over time. Service documents explicitly state that P2706 is an electrical fault within the solenoid assembly itself.
   How to confirm: After ruling out wiring and software issues, the diagnosis is confirmed by replacing the solenoid pack. An advanced scan tool may be able to read solenoid-specific data and circuit tests. The typical resistance for the MS solenoid should be around 1.3 ohms.
   Typical fix: Replace the entire solenoid pack assembly, along with the transmission filters and fluid. Ensure the correct part (connector color) is used for the model year.
   Est. part cost: $300-$600
2. Wiring Harness or Connector Issue 🟡 Medium Probability The main transmission harness connector is exposed to road salt and moisture, which can cause corrosion on the pins. Wires can also chafe or break, particularly in the harness leading to the transmission.
   How to confirm: Visually inspect the main round connector on the driver's side of the transmission for corrosion, bent pins, or damage. Pay close attention to pin 21, which is the circuit for the MS solenoid. Trace the harness for any signs of chafing or breaks.
   Typical fix: Clean the connector pins with an electrical contact cleaner, repair the damaged wire, or replace the harness section if necessary.
   Est. part cost: $10-$500
3. Outdated Powertrain Control Module (PCM) Software ⚪ Low Probability Multiple TSBs (e.g., 18-061-20 REV. A for 2018, 18-066-23 for 2019) list P2706 as one of many codes that may be addressed by a PCM software update, indicating the fault detection logic can sometimes be too sensitive or part of a larger software glitch.
   How to confirm: A dealership or qualified shop using a wiTECH scan tool can check your vehicle's VIN against available TSBs to see if a software update is available and applicable.
   Typical fix: Flash the PCM/TCM with the latest software version. This should always be checked before replacing expensive hardware.
   Est. part cost: $0-$200

Rare But Worth Checking

• Faulty Transmission Control Module (TCM): The TCM (which is integrated into the PCM on these trucks) is the last thing to suspect. All other possibilities, especially the solenoid pack and wiring, should be exhausted before considering a faulty control module.

Diagnosis Steps

1. Scan for Codes: Use an OBD-II scanner to confirm P2706 and check for any other related codes like P0700, P0868, or P0871.
2. Check for TSBs: Contact a dealership or use a professional database to check your VIN for applicable software updates, such as TSBs 18-061-20, 18-066-23, or 18-055-22. A PCM flash may resolve the issue without part replacement.
3. Inspect External Wiring: Carefully inspect the main round transmission connector on the driver's side of the 68RFE case. Look for green or white corrosion, pushed-out pins, or harness damage.
4. Test the Circuit: For advanced users, disconnect the transmission connector and test for resistance between pin 21 (MS Solenoid Control) and pin 10 (Transmission Control Relay Output) on the solenoid side. The resistance should be approximately 1.3 ohms. An open circuit or high resistance indicates a failed solenoid pack.
5. Inspect Fluid: When the pan is dropped, inspect the fluid and pan magnet. Burnt, dark fluid or excessive metal shavings can indicate more severe mechanical issues beyond the solenoid pack.
6. Replace the Solenoid Pack: If TSBs, wiring, and connectors are all good, the solenoid pack is the presumed cause. Drop the transmission pan, remove the valve body, and replace the solenoid pack. Be sure to use the correct part for your model year (grey/white connector for 2018, blue for 2019+).
7. Replace Filters and Fluid: While the pan is off, replace the transmission sump filter and spin-on filter. Reassemble and refill with Mopar ATF+4 fluid to the correct level.
8. Program and Relearn (2019+): For 2019 and newer models, use an advanced scan tool to program the 46-character code from the new solenoid into the TCM. Perform a transmission 'Quicklearn' procedure for all model years to ensure proper shift adaptation.
9. Clear Codes and Test Drive: Clear the codes and perform a test drive, allowing the transmission to shift through all gears to confirm the repair.

Parts You'll Likely Need

• Transmission Solenoid Block / Pack (2019-2020) (OEM #68456067AA) — This is the most common failure point for P2706 on 2019+ models. It has a blue electrical connector and requires programming upon installation.
  Trusted brands: Mopar, Revmax (P/N 68RFE-801B), ATS Diesel (P/N 3030162464)
  OEM price range: $300-$450
  Aftermarket price range: $350-$600
• Transmission Solenoid Block / Pack (2018) (OEM #68353383AB) — This is the most common failure point for P2706 on 2018 models. It has a grey or white electrical connector.
  Trusted brands: Mopar, Revmax (P/N 68RFE-801), SunCoast, ATS Diesel
  OEM price range: $350-$550
  Aftermarket price range: $375-$450
• Transmission Filter Kit (Sump and Spin-on) (OEM #5013470AE) — These must be replaced whenever the transmission pan is removed to service the solenoid pack.
  Trusted brands: Mopar, Wix, Baldwin
  OEM price range: $40-$60
  Aftermarket price range: $25-$45
• Mopar ATF+4 Transmission Fluid — The correct fluid must be used. A pan drop and solenoid replacement typically requires 7-9 quarts.
  Trusted brands: Mopar, Valvoline, Castrol
  OEM price range: $10-$15 per quart
  Aftermarket price range: $7-$12 per quart

Related Codes That Often Appear With This One

• P0700 — This is a generic code indicating the TCM has stored a fault. It almost always appears with any specific transmission code like P2706.
• P0868 — This code means 'Line Pressure Low'. The MS solenoid helps control hydraulic pressure, so a fault in its circuit can lead to the TCM detecting incorrect line pressure.
• P0871 — This code relates to the Overdrive Pressure Switch. Since the MS solenoid is involved in the hydraulic circuit for various gears, a fault can trigger related pressure switch codes. An owner on RamForum.com reported P0871 and P2706 together, which led to a valve body replacement.

Technical Service Bulletins (TSBs) & Recalls

• For 2019 models, this TSB involves a PCM software update to address a very long list of potential DTCs, including P2706. This indicates the original software logic could be overly sensitive. It is not a guaranteed fix for a hard electrical failure but should be checked before parts replacement.
• Similar to the others, this TSB for 2020 models lists P2706 among dozens of other codes that can be addressed by a PCM flash. The sheer number of codes suggests the update corrects broad monitoring strategies within the PCM.
• This TSB for 2020 models also includes P2706 in a list of faults that may be resolved with a PCM software update. It also mentions enhancements for idle stability and downshift behavior.
• Specifically for 2018 models, this TSB notes that a PCM flash can resolve P2706, suggesting a software fix should be considered before replacing hardware on this model year.

Platform-Specific Known Issues

• The solenoid pack on the 68RFE transmission is a well-documented weak point that is prone to failure from heat and vibration, making P2706 a very common code for this platform.
• A part design change occurred for the 2019 model year. Owners and technicians must be careful to use the correct solenoid pack, as the grey/white connector (2018) and blue connector (2019+) versions are not interchangeable.
• For 2019+ models, the replacement procedure is more complex as it requires programming a unique 46-character ID from the new solenoid into the vehicle's computer using a compatible scan tool.

Mechanic-Grade Diagnostic Values

• Multi-Select (MS) Solenoid Coil Resistance — expected: ~1.3 Ohms. Failure: A reading significantly higher or lower, an open circuit (infinite resistance), or a short circuit (near zero resistance).
• Pressure Control (PC) Solenoid Resistance — expected: ~4.9 Ohms. Failure: A reading significantly outside this specification. While not the direct cause of P2706, it helps identify a faulty solenoid pack during testing.
• MS Solenoid Control Circuit (T140) Continuity — expected: Less than 5.0 Ohms. Failure: Resistance above 5.0 Ohms when measured from the TCM connector to the transmission harness connector indicates an open or high-resistance wire.

Scan Tool Commands That Help

• wiTECH (or equivalent advanced scan tool): Solenoid PI Curve Programming — This is a mandatory step for 2019 and newer models after replacing the solenoid pack. The 46-character alphanumeric code from the new solenoid's QR code must be entered into the TCM. Failure to do so will result in poor transmission performance.
• wiTECH (or equivalent advanced scan tool): Quick Learn / Transmission Relearn — This procedure should be performed after any major transmission service, including solenoid pack replacement, for all model years. It resets the clutch volume index (CVI) and allows the TCM to adapt to the new components for optimal shift quality.
• wiTECH (or equivalent advanced scan tool): Actuate Solenoid / VCU Outputs Test — During diagnosis, a technician can use the scan tool to command the MS solenoid on and off to see if it responds electrically. This can help confirm if the fault is active and within the solenoid itself before disassembly.

Wiring & Ground Locations

• Main Transmission Connector (C1) — On the driver's side of the 68RFE transmission case. It is a large, round connector.. This is the primary interface between the TCM and the entire solenoid pack. It is exposed to road debris and moisture, making it a common point for corrosion and pin damage.
• Pin 21 (MS Solenoid Control) — Within the main round transmission connector.. This specific pin carries the control signal from the TCM to the Multi-Select solenoid. All electrical tests for the MS solenoid circuit (resistance, continuity, short-to-ground) are performed using this pin as a reference.
• Pin 10 (Transmission Control Relay Output) — Within the main round transmission connector.. This pin provides the ground or return path for the solenoid circuit tests. Resistance is measured between Pin 21 and Pin 10 to test the solenoid coil itself.
• Engine/Transmission Ground Strap — Typically runs from the back of the cylinder head to the firewall or frame.. While not a direct cause of a specific solenoid circuit code, a poor or corroded main ground strap can cause a variety of electrical issues and unpredictable behavior in the transmission control system.

Real Owner Repair Stories

• YouTube video 'P2706 fix for 09 Hemi Ram' (2009 Ram 1500 (with a similar RFE transmission architecture)) — Truck got stuck in 4th gear (limp mode). After restarting, it experienced very long, delayed shifts. Codes P0700 and P2706 were present.
  ❌ Tried (didn't work) Restarting the vehicle only provided a temporary fix.
  ✅ What actually fixed it The owner replaced the transmission shift solenoid pack located inside the transmission pan, along with both transmission filters. This resolved all shifting issues and cleared the codes.

OEM Part Supersession History

• 68353383AB → 68353383AC — Standard part revision by the manufacturer.
  Heads up: Applies to 2018 and earlier models with the grey/white connector. These parts are interchangeable with older numbers like 5170877AF and 52119435AF.
• 68456067AA → 68456067AB — Standard part revision by the manufacturer.
  Heads up: Applies to 2019 and newer models with the blue connector. Part number 68367309AA was also replaced by this series. These parts are not backward compatible with 2018 or older transmissions.

Model Year Variations Within This Range

• 2018: Uses the 4th generation Ram chassis and a 68RFE solenoid pack with a grey or white connector (P/N 68353383AB or superseding numbers). This part does not require QR code programming.
• 2019-2020: Uses the 5th generation Ram chassis and an updated 68RFE with a different valve body and solenoid pack. The solenoid pack has a blue connector (P/N 68456067AA or superseding numbers) and features a dedicated TCC control solenoid. Replacement requires scanning a QR code on the new solenoid and programming a 46-character 'PI Curve' code into the TCM using a scan tool.