RAM Fault Code
Free · no signupP0730
Trans Temp Warning / Limp Mode (4th Gear)
System
Ratio / Slip
Symptom
Trans Temp Warning / Limp Mode (4th Gear)
Diagnosis & fix steps
LOGIC: Incorrect Gear Ratio (Underdrive/Overdrive Clutch Slip).
ACTION: Drop the transmission pan. Check for an unseated or cracked spin-on filter neck seal. Check mechanical line pressure at the case port (spec: ~60 PSI idle, ramping to >160 PSI under load). If line pressure is low, inspect the valve body separator plate for cross-leakage or blown accumulator seals.
Red Seal field insights
Valve Body Cross-Leaks: The factory anodized aluminum accumulator pistons score the valve body bores over time. Pressure cross-leaks dump clamping force to the overdrive clutch pack, slipping and roasting the frictions under towing loads.
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
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Start your free trialRelated RAM fault codes
- P0734Slip Under Heavy Towing / Limp to 3rd
- P0713Delayed Cold Shifts / Check Trans Message
- P0744TCC Shudder / High Operating Temperature
- P0507Engine idles higher than normal (900+ RPM); Hissing sound from engine bay.
- P0751Missing 1st & 4th Gears / Long Shift Flare
- P0471Exhaust brake feels weak; Poor fuel economy; Turbo lag.
- P0871Check Engine Solid / Stuck in 4th Limp
- P0401Rough idle; EGR "Service" message; High intake temps.
- P0876Erratic Shift Stumble / 4th Gear Limp
- P020FEngine "stumble" or miss; Knocking sound under load; Increased exhaust smoke; CEL on.