P0733 on 2023 Dodge Challenger: Gear 3 Incorrect Ratio Causes and Fixes

What's Unique About the 2023-2023 Dodge CHALLENGER

The 2023 Challenger, equipped with the ZF-designed 8-speed automatic transmission (850RE/8HP70), has a well-documented issue with the 'D' clutch hub. The original hub was made of a softer cast aluminum that can wear prematurely from contact with the steel clutch plates, causing the splines to fail and leading to slippage. Fortunately, Dodge has acknowledged this through Technical Service Bulletins (TSBs) and created a specific repair kit, allowing for a targeted fix rather than a costly full transmission replacement, which might be the only option on other vehicles.

Diagnostic Flowchart

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

Symptoms You May Notice

• Check Engine Light illuminated
• Vehicle enters 'limp mode' (stuck in one gear, often 3rd or 4th)
• Harsh or jerky shifting, especially into 3rd gear
• Transmission slipping (engine RPMs rise without an increase in speed)
• Delayed or failed engagement of gear
• Reduced fuel economy
• Vehicle will not move in reverse (as the D-clutch is also used for reverse)
• Banging or clunking noise on a cold start when shifting into gear

Most Likely Causes

1. Internal 'D' Clutch Failure 🔴 High Probability This is a known issue acknowledged by the manufacturer through multiple Technical Service Bulletins (TSBs), including #21-009-25 and #9100390. The original clutch hub is made of a cast aluminum that wears out from the steel clutch plates. This failure is widespread across many Stellantis vehicles using the 8HP series transmissions.
   How to confirm: Diagnosis is confirmed by a qualified technician by the presence of related codes like P1DA8 or P1D92, referencing the TSBs for vehicles with over 7,000 miles, and performing a clutch air pressure test on the D-clutch circuit as per the service library procedure. In some cases, the manufacturer requires the dealer to drop the pan and photograph any metal debris before approving a warranty repair.
   Typical fix: Installation of the manufacturer-specified 'D Clutch Repair Kit' (Part No. 68676892AB) as per TSB instructions. This involves partially disassembling the transmission. An aftermarket upgrade from Sonnax (Part No. 35570-70K) replaces the aluminum hub with a more durable steel one. 🎬 Watch: A deep dive into the D clutch overhaul process.
   Est. part cost: $250-$450 for the OEM Mopar repair kit.
2. Low or Burnt Transmission Fluid ⚪ Low Probability → Shop Transmission Assembly While possible, it's an unlikely root cause given the prevalence of the TSB for the D-clutch. These 'sealed' transmissions do not have a traditional dipstick, and checking the level is a complex, temperature-dependent procedure that must be done on a level hoist.
   How to confirm: Check the transmission fluid level and condition via the service procedure. Fluid should be at the correct level, have its characteristic color (not brown or black), and not have a burnt smell.
   Typical fix: Perform a transmission fluid and filter service with the correct Mopar ZF 8 & 9 Speed ATF. This rarely resolves P0733 if the D-clutch is already damaged.
   Est. part cost: $150-$250 for fluid and filter.
3. Faulty Shift Solenoid ⚪ Low Probability → Shop Transmission Valve Body While a possible cause on many vehicles, the TSBs for the Challenger point so strongly to the mechanical clutch failure that solenoids are an unlikely culprit for this specific code. This should only be investigated after the D-clutch issue is ruled out.
   How to confirm: Testing solenoid resistance and operation with a high-end scan tool. This is usually done after ruling out fluid issues and the known TSB.
   Typical fix: Replace the specific solenoid within the valve body.
   Est. part cost: $100-$200 per solenoid.

Rare But Worth Checking

• Valve Body or TCM Failure: → Shop Transmission Valve Body A failure in the transmission's valve body (mechatronics unit) or the Transmission Control Module (TCM) could theoretically cause this code, but it is far less common than the documented mechanical clutch issue. This should only be considered after all other possibilities, especially the TSB, are exhausted.

Diagnosis Steps

1. Verify the code P0733 with a quality OBD-II scanner.
2. Check for other related DTCs, specifically P1DA8 and P1D92, as mentioned in TSBs.
3. Check the vehicle's mileage. If it is over 7,000 miles (11,265 km), the issue is highly likely to be the one described in TSB 21-009-25.
4. Consult TSBs #21-009-25 and #9100390. These documents are the most critical diagnostic step for this specific vehicle and code.
5. If the TSBs apply, perform a clutch air pressure test on the D-clutch circuit as per the service library procedure to confirm the internal leak/failure.
6. If the pressure test fails, the diagnosis is a failed 'D' clutch pack. The recommended procedure is to install the repair kit.
7. As a preliminary step, a technician may check the transmission fluid level and condition, but this is unlikely to be the root cause.
8. If the TSBs do not seem to apply (e.g., very low mileage or no other codes), proceed with advanced diagnostics of shift solenoids and valve body pressures with a suitable scan tool.

Parts You'll Likely Need

• D Clutch Repair Kit (OEM #68676892AB) — This is the specific fix recommended by Dodge in TSB 21-009-25 to address the root cause of P0733 on RWD vehicles like the Challenger. This part number supersedes 68676892AA. 🎬 See this video for a close-up look at the D clutch failure.
  Trusted brands: Mopar
  OEM price range: $280-$420
• Upgraded Steel D-Clutch Hub (OEM #35570-70K) — An aftermarket solution that replaces the failure-prone OEM cast aluminum hub with a durable steel version to prevent future wear.
  Trusted brands: Sonnax
  Aftermarket price range: $270-$300
• Mopar ZF 8 & 9 Speed ATF (OEM #68218925AB) — The correct transmission fluid is required when performing any internal transmission work or service.
  Trusted brands: Mopar
  OEM price range: $25-$35 per quart
• Transmission Filter (Pan Assembly) — The filter is integrated into the transmission pan and should be replaced whenever the transmission is serviced or internal repairs are performed.
  Trusted brands: Mopar, ZF
  OEM price range: $100-$150
  Aftermarket price range: $50-$100

Related Codes That Often Appear With This One

• P1DA8-00 — Incorrect Gear Ratio Clutch A, B, or D Defective. This code is explicitly linked with P0733 in TSB 21-009-25, pointing to the same D-clutch failure.
• P1D92-00 — Incorrect Gear Ratio - Clutch 4 Defective. This is another code mentioned in TSB 21-009-25 that points to the same internal clutch pack problem.
• P0700 — Transmission Control System Malfunction. This is a generic code that simply indicates the TCM has stored a fault. It will almost always be present with a more specific code like P0733.

Technical Service Bulletins (TSBs) & Recalls

• 21-009-25 REV. C: Links P0733 to an incorrect gear ratio in 3rd gear and specifies a mileage threshold (7,000 miles) for the diagnosis. It lists affected vehicles, related codes (P1DA8, P1D92), and the specific labor time (6.7 hrs for LA/LD platform).
• 9100390 Rev 1: Explicitly states that a 'D Clutch Repair Kit' is available for P0733 and that transmission replacement is NOT required.
• S2621000003 REV.A: Lists P0733 as a potential code for a range of 8-speed transmissions used by the manufacturer, including the 8HP70 found in the Challenger.

Platform-Specific Known Issues

• The 2023 Dodge Challenger equipped with 8-speed automatic transmissions is subject to a known issue with the 'D' clutch pack. Manufacturer TSBs #21-009-25 and #9100390 Rev 1 detail this specific failure, which causes code P0733. The bulletins confirm that a targeted repair using a specific clutch kit is the correct procedure, and a full transmission replacement is not necessary for this fault.

Mechanic-Grade Diagnostic Values

• Resistance of Electronic Pressure Regulating Solenoids (EPRS) — expected: 5.0 - 5.05 Ohms at 20°C (68°F). Failure: A reading of infinite resistance (open circuit) or zero ohms (short circuit).
• Resistance of On/Off Shift Solenoids (MV1) — expected: 10 to 11 Ohms at 20°C (68°F). Failure: A reading significantly outside this range, or infinite/zero ohms.

Scan Tool Commands That Help

• wiTECH: Reset Adaptive Values — This must be performed after replacing the valve body or clutch components to clear the old, learned clutch application data from the TCM's memory.
• wiTECH: Quick Learn / Static Adaptation (STADA) — Immediately after resetting adaptive values. This is a static procedure (vehicle not moving) that performs an initial relearn of the clutch fill times and pressures. It is required after any internal transmission repair to establish a baseline for proper shifting.
• wiTECH: Adaptation Drive Learn Procedure — If shift quality is still poor after performing the Quick Learn. This is a dynamic, on-road procedure where the vehicle is driven under specific load, speed, and temperature conditions to fine-tune the shift adapts for smoothness.

Wiring & Ground Locations

• TCM (Transmission Control Module) — The TCM is integrated into the valve body assembly (called a mechatronic unit) and is located inside the transmission oil pan.. Because the TCM is internal, external wiring issues are limited to the main harness connector at the transmission case, its power feeds, and grounds. A failure often requires removal of the oil pan and valve body to service.
• TCU/TCM Fuses — Power for the transmission controls is supplied through fuses in both the under-hood fuse box (Power Distribution Center) and the rear fuse box located in the trunk near the battery.. A loss of power to the TCM will cause numerous transmission fault codes and a no-shift condition. While not a common cause for an isolated P0733, it's a fundamental check for any transmission electrical issue.

Real Owner Repair Stories

• Ram Heavy Duty Forum (Ram with 8HP75-LCV 8-speed transmission, 26,000 miles) — P0733 'Gear 3 Incorrect Ratio' code and 'Service Transmission' message on the dash.
  ❌ Tried (didn't work) The initial diagnosis from the dealer was a faulty valve body.
  ✅ What actually fixed it The manufacturer (RAM) required the technician to drop the transmission pan and take pictures. Upon doing so, metal shavings were found. Due to the contamination, the final repair was a full transmission replacement, performed under warranty.
• AR15.com Forum (2015 Ram 1500 with 8-speed transmission, 77,000 miles) — On a cold start, experienced a 'bang' when shifting into reverse, followed by a lurch during acceleration which triggered the P0733 code.
  ❌ Tried (didn't work) Restarting the truck made it drive smoothly temporarily, but the code remained.
  ✅ What actually fixed it The user was documenting the beginning of the diagnostic process, which perfectly matches the classic symptoms of the D-clutch failure. The story confirms the symptom pattern that owners should watch for.

When the Usual Fixes Don't Work

• While the manufacturer TSBs state that a full transmission replacement is NOT required for code P0733, real-world owner experiences show this is not always the case. In an instance involving a Ram truck with the same transmission family, the code was set at just 26,000 miles. Although the initial diagnosis was a faulty valve body, the manufacturer required the dealer to inspect the transmission pan. Upon finding metal shavings, the repair escalated to a complete transmission replacement under warranty. This indicates that if the D-clutch failure is not caught early, the resulting debris can contaminate the entire unit, making the targeted TSB repair insufficient and necessitating a much more expensive full replacement.

OEM Part Supersession History

• 68676892AA → 68676892AB — Part revision by the manufacturer. Revisions typically address unforeseen weaknesses or manufacturing process improvements.
  Heads up: The new part number (AB) should be used. The old part number (AA) is obsolete.