6.0L Power Stroke Problems, Part 7: FICM
Much like a plugged oil cooler, where failure slowly creeps up on an unsuspecting truck owner, fuel injection control module (FICM) failure is also rampant on the 6.0L Power Stroke. Believe it or not, weak batteries damage the FICM’s internal circuitry. This can be mind-blowing for those who are new to the 6.0L Power Stroke, but it’s true. And with the FICM being required to pull off the 6.0L’s precise injection events, performance suffers considerably when this vital module heads south. Unfortunately, by the time you notice the FICM is on its way out, it’s too late… Below, we’ll explain exactly what the FICM’s role is on the 6.0L Power Stroke, why it fails and how you can prevent it from dying.
What Does The FICM Do?
The 6.0L Power Stroke’s fuel injection control module (FICM) is similar in functionality to the injector driver module (IDM) on the 7.3L Power Stroke. If an IDM is as unfamiliar to you as a FICM, the gist of it is that these modules take their orders from the powertrain control module (PCM is what Ford calls its ECM) and calculate the start of injection and injector duration. In the 6.0L’s case, the FICM sends a 48-volt, 20-amp pulse to the injector coil, the coil being what allows the spool valve to open and allow high-pressure oil to activate the fuel side of the HEUI injector. Hard-starting is almost always the first sign of an ailing FICM.
The Importance Of Adequate Voltage
In order for the injector to open at the right time and inject fuel for the correct duration, the FICM must send optimal voltage to the injector coil, which (as we already mentioned) is 48 volts. When voltage begins to drop off, the coils start to operate on a delay, causing injector misfires, rough engine operation, or excessive smoke. As a result of the inaccurate operation of the injector coil, the injector’s spool valve may not allow the appropriate amount of high-pressure oil into the injector, thereby hindering performance. Fuel economy normally takes a hit, too.
Dying batteries, an alternator than can no longer recharge the batteries or a combination of both are a FICM’s worst nightmare. For any other vehicle on planet earth, simply replacing the batteries or alternator and going on your way would be the norm. Unfortunately, when the batteries don’t supply at least 12.6 volts to the FICM, its delicate internal circuitry is damaged. What’s worse is that some folks misdiagnose a failing FICM for a bad injector. Always check the condition of the FICM with an appropriate scan tool before replacing an injector. Voltage supplied from the FICM to the injectors should be at least 45-48 volts with the key on, while cranking the engine and when the engine is running (note that 45 volts is the bare minimum allowed according to Ford).
What a Failing FICM Looks and Sounds Like
When you aren’t getting 48-volts to the injector coils you get: hard starts, rough idle, loss of power, poor drivability, and excessive smoke out the tailpipe—and in cold weather each of those symptoms will be amplified. Let the problem worsen and you’ll get a P0611 code for the FICM or injector misfire codes, and sometimes even PCM error codes. Once the FICM sends less than 30-volts to the injectors the engine won’t want to turn over at all, but you’ll definitely notice the problem before things get that bad.
Pulling The FICM
Located on the driver side valve cover under the degas bottle, the FICM is neither hard to find or remove. You can start by disconnecting both negative battery cables, unbolting the degas bottle using an 8mm socket and moving it out of the way, just be careful not to break off the degas bottle’s plastic fittings. To avoid any coolant splashing and a possible mess, a couple gallons of coolant can be drained from the system. For more working room you can also remove the air intake up to the turbo or remove the degas bottle completely.
There are several ways to address a bad FICM. The most affordable method is to remove the FICM, split it open and replace the power board side yourself. We’ll note that the power board side is what converts 12-volts from the vehicle into the 48-volt signal that’s needed to fire the injectors and is what usually goes out (the logic side, the side with all the resistors and capacitors, almost never fails). Another affordable option is to have your FICM repaired by a specialist, which generally ranges from $250 to $350. A third path is to perform a half-shell replacement, where the entire power supply half (including the case half) of the FICM is replaced. The final option is to start over with a brand-new unit.
How To Prevent FICM Failure
You have to keep a closer eye on your batteries in a 6.0L Power Stroke than you do in virtually any other vehicle. Our advice is to have your batteries load-tested every year, namely before winter hits, and if they’re questionable replace them. In addition, if you don’t think the factory alternator is charging the batteries, have it tested and replace it if need-be. Remember that weak batteries damage the 6.0L’s FICM, a damaged FICM means less injection efficiency and ultimately less horsepower and fuel economy.
More From Driving Line
- Just as dying batteries take out the FICM, the phenomenon known as stiction is the common killer of the 6.0L’s injectors. You can read all about it here.