Ford 4F27E and FNR5 problems: Focus, Fusion, Mazda3

TSS parts for the Ford 4F27E transmission: filter, Dorado overhaul kit and friction plates

In short

The 2000 to 2011 Focus automatic has the 4F27E 4-speed; Mazda calls its version FN4A-EL, and the 5-speed version is the FNR5, which Mazda calls FS5A-EL.
The FNR5 isn't a 4F27E with one more gear: they share the filter, pan gasket, band and other parts, but their ratios, planetary and valve body differ.
Per Ford, a 2-3 flare or no 3rd and 4th with burnt fluid means the direct clutch failed; the servo bore needs checking too.
If it neutrals going into 4th, ATSG points to the solenoid body gasket, shift solenoid A, the servo or debris in the separator plate.
Mazda requires flushing the cooler before installing a rebuilt unit: debris from the earlier failure is the most common cause of repeat failures.

If your automatic Focus, Fusion or Mazda3 flares going into 3rd, drops into neutral on the 3-4 shift, gets stuck in 3rd or bangs into gear, it most likely has a 4F27E, which Mazda calls FN4A-EL, or its 5-speed version, the FNR5. This article covers which cars have them, how to tell the 4-speed and 5-speed apart, their most documented problems according to Ford and Mazda bulletins and rebuild specialists, their codes, the fluid they take and which parts get replaced.

Which cars have the 4F27E and the FNR5?

The 4F27E is an electronic 4-speed front-wheel-drive automatic with an O/D button on the shifter. Ford built it at its Van Dyke plant in Sterling Heights, Michigan, and Mazda uses a version it calls FN4A-EL. The 5-speed is the FNR5, which Ford's Fusion owner guides call the "Mazda FNR5" and Mazda calls FS5A-EL.

Model	Automatic transmission
Ford Focus 2000 to 2011	4F27E 4-speed
Ford Transit Connect 2010 to 2013	4F27E 4-speed
Ford Fusion and Mercury Milan 2.3 (2006 to 2009)	FNR5 5-speed
Mazda 4-speed models, such as the Mazda3 2.0 through 2009	FN4A-EL, Mazda's version of the 4F27E
Mazda 5-speed models, such as the Mazda3 2.3 and 2.5, Mazda5 and CX-7 2.5	FS5A-EL, Mazda's name for the FNR5

Mazda's spec sheets tell you whether a given car has 4 or 5 speeds; in Mexico, for example, the Mazda3 2.0 had the 4-speed through 2009 and every 2010 to 2013 Mazda3 had the 5-speed. Mexico's first-generation EcoSport 2.0 automatic is a 4-speed too, which the Transmisiones Veinte 07 identifier lists as a 4F27E.

Not this family: the 2012-and-later Focus, which has the dual-clutch PowerShift; the 2001 to 2008 Escape and Tribute, with the CD4E; the V6 Fusion and Mazda6 and the CX-7 turbo, with 6-speeds from another family; the 2010-and-later Fusion 2.5, with the 6F35; and SKYACTIV Mazdas. More by model in our guides What transmission does my Ford have? and What transmission does my Mazda have?.

Is the FNR5 a 4F27E with one more gear?

No. They're the same family and share several parts, such as the filter, pan gasket, band, pump bushing and seal and the EPC solenoid, but every gear ratio is different: per Mazda Mexico, the 4-speed runs from 2.816 in 1st to 0.725 in 4th, and the 5-speed from 3.620 in 1st to 0.692 in 5th. The rear planetary and direct clutch hub don't interchange either (24 splines on the 4F27E, 25 on the FNR5): Transmission Digest documented a 4F27E that shifted from 2nd to neutral instead of 3rd because it had been fitted with an FNR5 planetary. The FNR5 also has an auxiliary valve body with an extra solenoid, and its gasket, friction and piston kits are different.

Even Ford's 4F27E and Mazda's FN4A-EL aren't identical part for part: according to Transmission Digest, the Mazda reverse piston is 1.375 in. tall and the Ford one 1.455 in. Ford and Mazda also letter the solenoids differently: per TransGo, Ford's shift solenoid A is Mazda's D. That's why it pays to identify the unit before ordering parts.

How to tell which one you have

The spec sheet or window sticker says whether the automatic is a 4-speed or a 5-speed.
The driver's door label: in Ford's owner guides, the transmission code is 2 on the 2008 Focus 4-speed and C on the Fusion with the FNR5.
The tag on the unit: per ATSG, on the 4F27E it's on the right side of the case.
For the shop: the FNR5 has an auxiliary valve body, and its range switch differs from the 4F27E's 9-pin switch.

2-3 flare or no 3rd and 4th: the direct clutch

It's the most documented problem. In technical service bulletin 14-0002, Ford says some 2008 to 2011 Focus and 2010 to 2013 Transit Connect vehicles with the 4F27E may have a 2-3 or 2-4 upshift flare or lack 3rd and/or 4th gear, with burnt fluid and codes P0733, P0734, P0751 and/or P0972. The cause is direct clutch failure, and Ford's repair is to overhaul the transmission with a direct clutch repair kit and a seal kit.

Ford also says to inspect the servo rod bore in the case: if it's worn, direct clutch pressure leaks, and it's repaired by installing a bushing. On these units the servo applies the 2-4 band and also releases it in 3rd. Transmission Digest confirms it on the 4F27E and the FNR5: a worn servo pin bore is the usual cause of a 2-3 flare before or after an overhaul, and it can come with gear ratio and solenoid codes. After the repair, Ford warns that the transmission relearns and may shift firmer than normal for several days.

Neutral on the 3-4 shift

Ford issued bulletins for 2002 to 2004 Focus models that missed 2nd or 4th or dropped into neutral shifting into 4th, and a service tip for a 3-4 flare or neutral on 2000 to 2003 models. According to ATSG, it's one of the most frequent calls to its tech hotline on the 4F27E (FN4A-EL), and the causes it lists are:

A failed bonded gasket on the solenoid body, leaking shift solenoid A feed pressure.
A mechanically failed shift solenoid A (SSD on a Mazda).
A failed servo.
Debris blocking an orifice in the separator plate.

Stuck in 3rd: fail-safe mode

According to ATSG, if the 4F27E loses electronic control, as with a blown fuse, it runs in fail-safe mode: 3rd gear only in every forward range, with maximum line pressure and the converter clutch released, while P, R and N still work. The Focus has no separate transmission module: the engine computer (PCM) controls the transmission. We found no source for the FNR5's fail-safe gear. Other causes of limp mode are in Why won't my automatic transmission shift?.

What about the O/D OFF light? If it's on steadily, that's normal: someone pressed the button on the shifter and turned overdrive off. A flashing light is different: per the 2008 and 2010 Focus owner guides, if the light flashes steadily or doesn't illuminate, have the transmission serviced soon, or damage may occur. What each shifter letter and button means is in What do the letters on an automatic shifter mean?.

Harsh engagement into Drive or Reverse, or harsh shifts

Ford issued several bulletins for 2000 to 2005 Focus models with harsh engagement, the check engine light and code P0705, a transmission range circuit failure. In the valve body, Sonnax documents wear in the pressure regulator bore on all four versions (4F27E, FN4A-EL, FNR5 and FS5A-EL): at one end it causes high line pressure, harsh shifts and overheating from reduced cooler and converter flow; at the other, low line pressure, soft shifts and burnt clutches and bands.

Not everything is the transmission: Transmission Digest documented a 2006 Focus with harsh garage shifts and no codes where a new valve body didn't help, because the cause was a poor stop light ground in the trunk that raised line pressure. Mazda also issued bulletins for a 1-2 shift shock on the 2004 and 2005 Mazda3. If it slips or shifts hard, our guide to why an automatic transmission slips or shifts hard also helps.

Shudder: the converter and code P0741

According to Sonnax, writing in Transmission Digest, code P0741 on the FNR5 and 4F27E really means the computer detected excessive converter clutch slippage. It can come from erratic speed sensors, the converter clutch solenoid, worn valve body bores, low line pressure or a glazed converter clutch, but most often there's a leak in the converter apply circuit, usually at the rear pump stator bushings, which they recommend replacing on every overhaul. On the 4F27E, shift solenoid B effectively works as the lockup solenoid, according to Transmission Digest.

On the 2000 Focus, Ford also issued bulletins for shudder or stalling when slowing to a stop, tied to the engine computer's calibration: make sure the computer has its latest calibration before opening the transmission.

Overheating or a burnt smell

Burnt fluid shows up in bulletin 14-0002 along with direct clutch failure, and pressure regulator wear reduces flow to the cooler, according to Sonnax. If you're repairing or replacing the transmission, Mazda requires power flushing the cooler and lines first: per its bulletin, the most common cause of repeat failures is lack of lubrication to the planetary gears, from debris of the earlier failure trapped in the cooler's internal mesh baffle. What the fluid's color and debris tell you is in Burnt transmission fluid, metal in the pan or water.

Common trouble codes

Code	What it points to
P0705	Transmission range circuit; Ford tied it to harsh engagement on 2000 to 2005 Focus models
P0715 and P0720	Input (turbine) and output speed sensors
P0731 to P0734	Incorrect ratio in 1st, 2nd, 3rd or 4th; P0733 and P0734 come with direct clutch failure
P0741	Excessive converter clutch slippage
P0751 and P0972	Shift solenoid A; listed in bulletin 14-0002
P0750 to P0759	Shift solenoids A and B (on the 4F27E, B handles the lockup)

Note that on the Focus the engine computer controls the transmission, and Mazda's solenoid letters differ from Ford's. Sun Transmissions explains codes P0705, P0715, P0730 and P0741.

What fluid does it take?

Focus with the 4F27E: early owner guides call for MERCON V and those from 2008 for MERCON LV. Ford now authorizes MERCON LV in every 4F27E, including for refilling the earlier ones.
Fusion with the FNR5: the owner guides called for Motorcraft FNR5 fluid (Mazda M5); Ford's current chart lists MERCON V.
Non-SKYACTIV Mazda3, Mazda5, four-cylinder Mazda6, CX-7 2.5 and Mazda2: Mazda ATF M-V. Mazda says it isn't the same fluid as MERCON V or MERCON LV, and that a generic or universal ATF may damage the transmission.
On the Focus and Fusion, the level is checked on the dipstick with the transmission warm, the lever in P and the engine running.
Ford says not to use transmission fluid additives, treatments or cleaning agents.

How it's diagnosed and repaired

Scan it: on the Focus, the transmission codes are in the engine computer.
Check the level on the dipstick, warm, and make sure it's the right fluid.
If it bangs into gear with no codes, check the electrical grounds too.
If it flares from 2nd to 3rd or has no 3rd or 4th, it's rebuilt with a direct clutch kit, checking the servo bore.
If you fit a used unit, check that its final drive ratio matches your car: Ford has a bulletin for delayed shifts after a transaxle or final drive ratio change.
Flush the cooler and lines before installing a rebuilt unit, and confirm whether it's a 4-speed or a 5-speed before ordering parts.

How much does the repair cost? It depends on what failed: a sensor, a solenoid or a ground isn't the same as a rebuild. Get a diagnosis before accepting a replacement transmission.

See TSS parts for the 4F27E and FNR5

TSS parts for the 4F27E and FNR5

The TSS catalog lists the parts for the whole family. The most requested are:

Deep pan filter with a 1-3/8 in. inlet, the best seller in this family, and shallow pan filter with a 5/8 in. inlet; confirm which one your car takes.
TSS Rojo and Dorado overhaul kits for the 4F27E and the FNR5; we explain the difference in TSS Rojo vs Dorado overhaul kits.
TSS friction plate packs for the 4F27E, FN4A-EL and FNR5.
2-4 (overdrive) band, molded servo piston and Farpack pan gasket.
Shift solenoids A and B, EPC solenoid, range switch and output speed sensor.
Pump bushing, seal and O-ring, and axle seals.

Before ordering, confirm whether your transmission is a 4-speed or a 5-speed. To buy online in the US, Sun Transmissions has the 4F27E and FN4A-EL and FNR5 and FS5A-EL collections.

TSS is an aftermarket brand with OEM-comparable quality and quality control on every product. You can buy it from our authorized distributors: in the United States from Sun Transmissions, and in Mexico the full TSS catalog at Transmisiones Veinte 07.

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