P0742 on RAM: How to Diagnose & Fix
Torque Converter Clutch Circuit Stuck On
3 RAM models · 5 documented issues · 3 critical · $150-$8,000 repair
P0742 on RAM by model: symptoms, diagnosis and fix
The 2007-2018 RAM 3500 with the 68RFE 6-speed automatic transmission suffers from premature failure when towing heavy loads (over 10,000 lbs). The 68RFE is a derivative of the older 545RFE and was not adequately engineered for the torque output of the 6.7L Cummins. The overdrive clutch pack, solenoid pack, and torque converter are the primary failure points. Overheating during sustained towing destroys the clutch packs and warps the valve body. Many trucks experience complete transmission failure between 80,000-150,000 miles if used for regular towing. Rebuild cost: $3,000-5,000. Built/upgraded transmission: $5,000-8,000.
Common Symptoms
- Transmission slipping under heavy load
- Flare between 3rd and 4th gear
- No 3rd gear or no overdrive
- Transmission overheating warning while towing
- Harsh or delayed shifts
- Check engine light with transmission codes
- Complete loss of forward or reverse gears
How to Fix
For minor issues: Complete fluid and filter change with Mopar ATF+4 (68218057AA) and solenoid pack replacement ($400-800). For overheating prevention: Install an auxiliary transmission cooler and keep temps under 220F. For rebuilds: Use a reputable heavy-duty builder (SunCoast, Randys Worldwide, BD Diesel). A properly built 68RFE with billet shafts, upgraded clutch packs, and triple-disc torque converter ($5,000-8,000) will handle 800+ lb-ft of torque. For 2019+ trucks, the Aisin AS69RC replaced the 68RFE.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Geno's Garage QSK2004 68RFE service kit
Verify transmission, pan and required fluid quantity.
- Genuine Mopar ATF+4 68218058AC
68RFE only; verify transmission and service versus overhaul fill quantity.
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Sources for this issue (3)
The RAM 3500 equipped with the Aisin AS69RC 6-speed automatic transmission experiences torque converter shudder, overheating when towing, delayed shifts, and premature wear. The torque converter lockup clutch develops a shudder at light throttle and highway speeds. When towing heavy loads (10,000+ lbs), the transmission temperature can spike rapidly, triggering limp mode. TSB 21-013-19 addresses torque converter shudder with updated fluid and converter. The AS69RC uses a specific Aisin fluid (Mopar 68218058AA) and using incorrect ATF+4 causes accelerated wear. Converter replacement runs $2,000-3,500.
Common Symptoms
- Shudder or vibration at highway speed (40-60 mph)
- Transmission overheating when towing
- Delayed or harsh shifts
- Transmission temperature warning light
- Limp mode activation while towing
- Slipping sensation during light acceleration
- Torque converter lock/unlock cycling
How to Fix
For shudder: First try a complete fluid change with Mopar Aisin-specific ATF (68218058AA) - NOT standard ATF+4. If shudder persists, torque converter replacement is needed ($2,000-3,500). Check TSB 21-013-19 for updated converter part number. For overheating: Install an auxiliary transmission cooler ($200-400, B&M or Derale) and reduce towing speed. Ensure the external transmission filter (if equipped) is clean. Some 2013-2018 trucks qualify for extended warranty coverage on the Aisin transmission.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Mopar ASRC transmission fluid 05189966AF
AS69RC/AS68RC/AS66RC applications specifying 05189966AF or supersession; verify transmission and package quantity.
- Genuine Mopar 68224232AA AS69RC transmission filter
2013-2018 Ram 3500 high-output 6.7L Cummins with AS69RC as listed; not Ram 2500 and not approved here for 2019-2025. Fitment/availability: In stock at review
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Sources for this issue (4)
The ZF 8HP 8-speed automatic transmission can experience harsh shifting, hesitation, and jerky behavior. Some units have failed prematurely. Early model years (2013-2016) seem most affected. Multiple TSBs have been issued for software updates.
Common Symptoms
- Harsh or delayed shifts
- Transmission slipping
- Jerky acceleration
- Hesitation when accelerating
- Check engine light with trans codes
How to Fix
First step: Get latest transmission software update from dealer (often free). Change transmission fluid and filter every 60,000 miles using ZF Lifeguard 8 fluid only. If problems persist, valve body replacement may be needed ($1,500-2,500). Full transmission replacement runs $4,000-6,500.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Dorman 265-850 8-speed transmission pan/filter conversion
Confirm transmission code and OE pan cross-reference.
- ZF LifeguardFluid 8 seven-liter service fill
Confirm 845RE/8HP75 fluid specification and total quantity separately rather than inferring.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipDIY repairs can save significantly - dealer charges $1,500-2,500 but DIY costs are typically 50-70% less
- TipGet a proper diagnosis before replacing parts - similar symptoms can have different causes
- TipSearch RAM 1500 forums and owner groups for real-world experiences and DIY guides
- TipGet multiple quotes from independent mechanics - dealer prices can be 2-3x higher for the same repair
The 2019+ RAM 1500 uses the ZF 8HP75 8-speed automatic transmission which exhibits harsh shifting, delayed engagement, hesitation between gears, and rough downshifts. While the transmission itself is mechanically robust, the calibration and TCM (Transmission Control Module) programming have been problematic since launch. Stellantis has released multiple software updates via TSBs to address shift quality. TSB 21-018-22 REV.A addresses rough 1-2 upshift and 2-1 downshift. Some trucks require valve body replacement if software updates do not resolve the issue.
Common Symptoms
- Harsh or jerky 1-2 upshift
- Rough 2-1 downshift when stopping
- Hesitation or delay when accelerating from stop
- Transmission hunting between gears on hills
- Clunking noise when shifting into Drive or Reverse
- Delayed engagement when cold
How to Fix
First step: Visit dealer for the latest TCM software update (free under warranty). Reference TSB 21-018-22 REV.A for shift quality improvements. Perform a transmission adaptation reset after the update (dealer procedure). If software updates do not resolve the issue, valve body replacement may be needed ($800-1,500). Ensure transmission fluid is at proper level with correct Mopar ZF 8/9 speed ATF (68218925AB). Some owners report improvements after a complete fluid and filter change ($250-400).
The RAM ProMaster City uses the ZF 9HP48 9-speed automatic transmission which is plagued with harsh shifting, delayed engagement, gear hunting, and premature failure. The transmission struggles with low-speed maneuvers, often jerking or hesitating during parking lot driving. Some owners report the transmission failing to shift out of first gear or getting stuck in gear. Multiple TSBs have been issued for shift quality calibration (TSB 21-008-18 REV.C). The 9HP has been the subject of class-action lawsuits across multiple Stellantis vehicles. TCM software updates may help but many trucks need valve body replacement ($1,200-2,000) or complete transmission rebuild ($3,000-5,000).
Common Symptoms
- Harsh or jerky shifting at low speeds
- Hesitation when accelerating from stop
- Transmission hunting between gears
- Stuck in one gear (fails to upshift)
- Clunking when shifting into Drive or Reverse
- Delayed engagement (2-3 second delay)
- Check engine light with transmission fault codes
How to Fix
Start with TCM software update at dealer (free under warranty), reference TSB 21-008-18 REV.C. Have dealer perform transmission adaptation reset after update. If shifts remain harsh, request valve body inspection/replacement ($1,200-2,000). Ensure correct ZF 9-speed fluid is used (Mopar 68218925AA). Complete fluid change (not just drain and fill) every 40,000 miles. If transmission has failed completely, replacement/rebuild costs $3,000-5,000. Some owners opt for remanufactured transmissions from Jasper or AAMCO.
Sources for this issue (3)
P0742 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 P0742 mean on a RAM?
P0742 stands for "Torque Converter Clutch Circuit Stuck On." P0742 means the torque converter clutch (TCC) circuit is stuck on, meaning the lockup clutch that mechanically links the engine to the transmission stays engaged when it should release. The computer commands the clutch on and off, and when it detects the converter clutch remaining applied, it sets this code. The classic symptom is the engine stalling when coming to a stop, similar to driving a manual without pushing the clutch in, along with possible harsh shifts or poor fuel economy. It points to a hydraulic or solenoid problem inside the transmission rather than the engine. On RAM it is documented across 3 models: 3500, 1500, ProMaster City.
What are the most common causes of P0742?
The most common causes of P0742 are: Stuck or failed torque converter clutch solenoid, Stuck valve in the valve body (TCC apply valve), Contaminated or degraded transmission fluid, Internal transmission hydraulic leak holding the clutch on, Wiring or connector fault to the TCC solenoid, Faulty torque converter, Dirty or clogged transmission filter. The specific cause varies by vehicle.
How much does it cost to fix P0742 on a RAM?
Published repair estimates on RAM range from $150 to $8,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0742 on a different make?
View P0742 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.