Your ICP sensor - 7.3 Injection Control Pressure Sensor - continuously monitors your diesel engine's oil delivery pressure.
The 7.3 ICP sends the current pressure reading to the Powertrain Control Module (PCM) which in turn signals the 7.3 Injection Pressure Regulator (IPR) to add or reduce pressure.
The three of them, along with the 7.3 HPOP, provide enough oil pressure to the oil rails so that when you press on the accelerator, your 7.3 injectors actuate, your engine gets diesel and the cylinders fire ... ideally, as smoothly as possible.
Just what does the ICP sensor on a 7.3 Powerstroke do?
In a diesel engine as heavily-reliant on adequate and correct oil pressure as the 7.3 HEUI system is, the 7.3 PCM needs instant and accurate information on the amount of pressure in the 7.3 oil rails. This is so that the PCM can determine how much pressure, at any given second, to deliver to the injectors for maximum fuel firing efficiency.
Broken down, the 7.3 Injection Control Pressure sensor tells the PCM what the oil pressure is in the driver's side oil rail. It uses a five volt signal and returns it to the PCM. This analog voltage signal to the PCM tells it how much pressure's in the oil rails.
And in conjunction with the 7.3 IPR, HPOP, and PCM, the Injection Control Pressure Sensor on your 7.3 provides this pressure information feedback in a continuous loop.
Broken down and simplified, these are the four components on your 7.3 Powerstroke diesel that regulate oil pressure in order to accurately and efficiently actuate your injectors enabling them to fire and create combustion.
If, or should I say when, your 7.3 ICP fails, the PCM in your truck won't know how much pressure's in the oil rails and it won't be able to regulate that pressure to efficiently actuate the injectors, resulting in poor engine performance.
What will actually happen is that it will get incorrect data from your 7.3 ICP and then deliver incorrect oil pressure, causing at best rough-running and at worst a no-start condition.
But let's not get ahead of ourselves.
Just where is the ICP sensor on a 7.3 Powerstroke, anyway?
Your 7.3 diesel's ICP sensor is located on the driver's side cylinder head toward the front of the engine compartment ... near the HPOP.
7.3 Powerstroke ICP sensor failure symptoms include:
The worst symptom of a bad, i.e. failed, ICP sensor on your 7.3 is that your engine just won't start at all.
But, to tell you the truth, so many failed parts on your 7.3 diesel cause the exact same symptoms that it's hard to tell what's not working.
Luckily, and if you have even an inexpensive ODBII scan tool combined with a free to cheap cell phone app, you can do some further ICP investigation.
If there's oil on the sensor's female plug receptacle, its leads, or around the pigtail connector male plug, you've got a failed ICP sensor.
If your Check Engine Light - CEL - comes on and you have a diagnostic tool to read the OBD-II trouble code, a code of P2285 or related ICP codes P2283, P2284, P2286, and P2287 point to trouble in your 7.3's ICP sensor electrical circuit or the sensor itself.
But before we get to scan tools, apps, and PIDs...
One quick way to diagnose a failed 7.3 ICP sensor is to lift the plastic clip on the wiring connector and remove the pigtail from the sensor. If there's oil on the sensor's plug receptacle, its leads, or around the pigtail connector, you've got a failed ICP sensor.
As mentioned above, the 7.3 ICP sensor measures pressure from the oil rail. Over time, all that oil pressure on your ICP pushes and exerts force on the sensor's internal components and plastic electrical connector housing. A couple hundred thousand miles of that and it's bound to fail. When it does, the oil will cause bad electrical readings as well as corrode the sensor's ability to send those signals.
Here's how to further test ICP sensor 7.3 as the cause of whatever above symptoms your Powerstroke's having.
With your engine running, pull the connector, disconnect your 7.3 ICP pigtail. This causes the PCM to deliver a default ICP value of 725 PSI at idle. As apposed to the stock setting of 500-550 PSI at idle. There should be a noticeable difference in idle when you unplug your ICP.
If you don't feel a difference, your 7.3 ICP is most likely already running on this default setting. This could mean that your ICP is bad.
Now, some people do this, but I wouldn't recommend running your 7.3 without ICP readings. The sensor's there for a reason. Replace it if it's bad.
If you have a scan tool you can view your 7.3 diesel's various ICP pressure readings with the following PID.
Here are some helpful numbers in diagnosing your 7.3 ICP pressure.
Warmed up, your 7.3 diesel’s ICP pressure at idle should be close to 480-500psi (for a 99-2003) with about 8-12% IPR duty cycle.
At WOT in neutral your 7.3 ICP should be – 1100-1200psi – With a caveat that after s/n 896812, after 3 minutes of WOT with no load, the number would be 1800psi. Because at WOT, your 7.3 ICP pressure number will spike and then level off if you stay on the throttle.
A good, healthy 1999-2003 7.3 HPOP can hold between 2800-3000psi during hard acceleration. A lot of 7.3s do just fine with an HPOP that produces 2600-2800psi.
And, if you're a masochist...
If you've got an Auto Enginuity scan tool or SnapOn scan tool and want to get into the grit and grime of troubleshooting... Well, you're either a tech or you seriously love troubleshooting. In any case, here are some numbers from the service CD on normal PSI, MPa - Megapascals, and 7.3 ICP Voltage.
I've had an aftermarket 7.3 ICP sensor in my 2002 Ford F250 7.3 for about 2 years, so it works for me. If you're "OEM or death" and have the money, here's an OEM one on Amazon.
OEM Ford 7.3 ICP Part Number - F6TZ-9F838-A
International 7.3 ICP Part Number - 1807329C92
Interchangeable 7.3 ICP Part Numbers - F4TZ-9F838-A , F6TZ-9F838-A, 1807329C92, ICP102
Given that an ICP sensor's a pretty simple part, this 7.3 ICP sensor is OEM, it works, and will most likely get the job done with a minimum of headache.
On the other hand, if you're like me and are willing to roll the dice to save some dough, here are a couple of aftermarket 7.3 ICPs that should do the trick. Mine's been in for a couple years now and still going strong. Knock on wood...
NOTE: I've got an enhanced AAA towing membership as insurance against my ... "proclivity" to use aftermarket parts.
How to change the ICP sensor on 7.3 Powerstrokes.
9 lb./ft. - 108 lb./INCH
As you can see, the three wires on the replacement pigtail aren't color-coded. So a "trick" I use is to remove, splice, and solder ONE WIRE AT A TIME, matching it to the same wire on the old pigtail as I go.
The ICP sensor on your 7.3 Powerstroke diesel is a pretty common failure item. When it does fail the good news is it's relatively easy to diagnose, remove, and replace with a new part to get you and your 7.3 Powerstroke back on the road.
Oh, and don't forget to check and replace the ICP pigtail if necessary.
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