The Winnebago Solis is a compact Class B motorhome built on the Ram ProMaster chassis — a deliberate departure from the Sprinter platform that gives it a lower price point and wider body. The Solis attracts buyers who want a livable van layout without the Mercedes-Benz premium. But the ProMaster platform brings its own set of quirks, and the Solis community has documented them thoroughly.

Here are the 7 most common Winnebago Solis problems and what to do about them.

1. ProMaster 9-Speed Transmission Recall

Ram ProMaster vans from 2019–2021 with the 9-speed automatic transmission were subject to a significant Stellantis recall for transmission shifting problems. Affected vans could experience harsh shifts, unexpected downshifts, and in some cases a failure to engage Park. This directly affects Solis units built on those model year chassis.

Fix: Check your VIN immediately at nhtsa.gov. If the recall is open, contact a Ram ProMaster dealer for a free software update to the transmission control module. If you’ve experienced rough shifting and the recall has been completed, a transmission fluid flush and refill with the correct TF-0870 fluid often resolves residual shift quality issues.

2. Truma Combi Heater Not Igniting

The Truma Combi is the heart of the Solis’s heating and hot water system, but owners frequently report ignition failures after storage or in cold weather. The system makes three ignition attempts before locking out.

Fix: First ensure the LP tank valve is fully open and the tank has adequate fuel. Air in the gas line after storage is the most common cause — attempt the ignition sequence twice to purge it. For a lockout reset, hold the power button for 5 seconds. Error codes 3 and 10 indicate igniter electrode issues. Check that the exhaust and intake vents on the exterior are not blocked by debris or ice.

3. 59P vs. 59PX Sleeping Arrangement Confusion

The Solis 59P has a fixed rear bench that converts to a bed, while the 59PX has a motorized drop-down overhead bed in addition to the rear seating area. Many buyers confuse the two at purchase, and the difference significantly affects the van’s livability for couples. On used units, previous owners sometimes remove the overhead bed components, further complicating identification.

Fix: On the 59PX, the overhead bed motor and mounting track are visible in the rear ceiling area even when stowed. The 59PX also has a dedicated motor control button near the rear. If buying used, verify the floorplan against the Winnebago VIN decoder to confirm what you’re actually purchasing.

4. Parts Backorder Crisis for ProMaster Components

The ProMaster chassis has historically suffered from severe parts availability issues, particularly for body panels, transmission components, and HVAC parts. During 2021–2023, wait times of 3–6 months for certain parts were common. This is less severe now but remains a consideration for owners who need quick turnaround on repairs.

Fix: Keep a relationship with a Ram ProMaster commercial fleet dealer rather than a consumer dealer — they typically have better access to parts inventory. For Winnebago-specific coach parts, Lichtsinn RV in Forest City, Iowa maintains one of the best Solis parts inventories in the country.

5. ProMaster Front-Wheel Drive Traction Limitations

Unlike the Sprinter-based Winnebago models, the Solis is front-wheel drive. This catches many buyers off guard when the van struggles with traction on grass campsite surfaces, wet boat ramps, or light snow. The front wheels are carrying engine weight and handling steering — adding traction stress under load reduces capability significantly.

Fix: Carry a set of MaxTrax or similar traction boards for soft ground recovery. Maintain proper tire pressure — overinflated front tires dramatically reduce traction on soft surfaces. Consider Michelin Agilis CrossClimate tires as an upgrade if you frequently camp off paved surfaces; they provide significantly better all-surface traction than the OEM tires.

6. Compact Galley — Water System Pressure Issues

The Solis galley is genuinely compact, and the water system uses a smaller pump than larger Winnebago models. Owners report low water pressure at the faucet, especially when multiple fixtures are used simultaneously, and occasional pump cycling noise that disrupts sleep.

Fix: Install a SHURflo accumulator tank inline with the water system — this eliminates pump cycling noise and improves pressure consistency. Check all PEX connection fittings under the galley panel annually, as vibration from driving can loosen push-fit connections on ProMaster-chassis vans over time.

7. Roof Fan Lid Rattle at Highway Speed

The MaxxAir or Fantastic vent fan lid on the Solis frequently develops a rattle at highway speeds due to the van’s relatively high roofline catching wind. This is one of the most reported annoyances in the Solis community — minor in impact but relentless in irritation.

Fix: Install a Maxxair vent cover/rain shield over the existing lid — it breaks the wind pattern and eliminates the rattle in most cases. As a temporary fix, place a folded microfiber cloth under the lid edge at highway speed. The vent cover mod takes about 20 minutes and costs under $50.

The Bottom Line

The Winnebago Solis is a well-designed, livable van at a price point below the Sprinter-based models. Most of its issues are ProMaster platform-related rather than Winnebago-specific, and the owner community is active and helpful.

For instant answers to Solis technical questions, try SprinterRVDesk.com — a free AI expert for Winnebago owners. Select Solis from the model menu and ask anything about your van.