MajorCommonTransmission

RAM 1500: Solenoid pack failure, limp mode and slipping (3rd gen 45RFE/545RFE auto)

Solenoid pack failure, limp mode and slipping (3rd gen 45RFE/545RFE auto) is a common transmission fault on the RAM 1500 on the 2002–2008 cars, and we rate it major. Putting it right costs $900 to $8,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 22 documented faults on the RAM 1500.

Vehicle: RAM 1500
Years: 2002–2008
Fuel: petrol
Gearbox: auto
System: Transmission

This page covers the RAM 1500 as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All RAM 1500 faults22 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Mechatronic / valve body yet. We would rather show none than show a picture of a different part.

What goes wrong

The 2002 to 2008 Ram 1500 V8 uses Chrysler's electronically controlled 45RFE and later 545RFE automatic. A common fault is the internal solenoid pack, which sets codes such as P0755 or a solenoid circuit fault and drops the gearbox into limp mode, holding second or third gear with no shifting. The fix is replacing the whole solenoid block, not one solenoid. These gearboxes also suffer from slipping, flare and delayed engagement as clutches wear, especially under towing, which ends in a rebuild. Driving on in limp mode overheats and further damages the gearbox. There was no recall.

What you would notice

Stuck in one gear with high revs at speed (limp mode)
Check engine light with a harsh or no shift
Delayed engagement when selecting Drive or Reverse
Slipping or flaring between gears, especially when towing
Problem clears after switching off and restarting, then returns

How to check it

Where to look. Automatic transmission under the cab; solenoid pack is inside the transmission on the valve body

Start the truck cold and make sure the check engine light goes out. Select Reverse then Drive and count how long it takes to engage; more than a second or two is a warning sign. On the test drive, accelerate gently and then firmly and feel for clean shifts through all gears, and watch for revs flaring between gears. Drive long enough for the gearbox to get fully warm, because limp mode often shows up once it is hot. Ask whether the transmission has had a solenoid pack, service or rebuild, and whether it has towed. If a workshop inspection is possible: scan the transmission computer for stored and history codes (P0755, P0750, P0700, P0731-P0736), and check the fluid level and condition at the correct temperature.

Parts involved: Mechatronic / valve body.

What it costs to put right

$900 to $8,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has the transmission ever gone into limp mode?”
“Has the solenoid pack been replaced, or the gearbox rebuilt?”
“Has the truck been used for towing?”

Now check the RAM 1500 you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

Go-Parts: OBD P0755 Dodge Ram 1500 2002-2008 4.7L V8 (failed solenoid pack in 45RFE/545RFE, limp mode stuck in 2nd or 3rd)
Wikipedia: Chrysler RFE transmission (45RFE/545RFE applications and known issues)
Powertrain Products Knowledgebase: Everything You Need To Know About Our Remanufactured 545RFE Transmissions

RAM 1500 buyer questions

Is solenoid pack failure, limp mode and slipping (3rd gen 45rfe/545rfe auto) serious on a RAM 1500?

We rate it major and common on the RAM 1500. The 2002 to 2008 Ram 1500 V8 uses Chrysler's electronically controlled 45RFE and later 545RFE automatic. A common fault is the internal solenoid pack, which sets codes such as P0755 or a solenoid circuit fault and drops the gearbox into limp mode, holding second or third gear with no shifting. The fix is replacing the whole solenoid block, not one solenoid. These gearboxes also suffer from slipping, flare and delayed engagement as clutches wear, especially under towing, which ends in a rebuild. Driving on in limp mode overheats and further damages the gearbox. There was no recall.

How much does it cost to fix on a RAM 1500?

$900 to $8,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which RAM 1500 years are affected?

Our research records this fault on the 2002–2008 RAM 1500. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.