2002 7.3 excursion idm location

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IDM location?

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Does anyone know where the IDM is located on a 2002 7.3 F-350 dually? I have the factory manual on CD and all it tells me is that it is in the engine bay on the left. I thought I read somewhere on this site that it was under the left front wheel well, but I cant find it for the life of me. /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/confused.gif Thanks, Ron  

Drivers side firewall, follow the wiring harness back from the valve cover.  

I followed the harness and it goes through the firewall into the cab and into what I thought was the PCM. Is the IDM inside the cab behind the e-brake? If that's the IDM, where is the PCM? Thanks, Ron  

Remove the LF wheel well liner and you will see it up inside the fender. It's right behind the F XXX emblem on the fender. FMT  

Thanks, It looks like it will be a weekend job. Thanks again. Ron  

[ QUOTE ] Thanks, It looks like it will be a weekend job. Thanks again. Ron [/ QUOTE ] yes, it is a pain in the a** to get to. be patient and long extensions is my best advice. redrocket  

Located here /ubbthreads/images/graemlins/biggrin.gif /ubbthreads/images/graemlins/biggrin.gif  

THANKS MO_SMOKE!!! /ubbthreads/images/graemlins/laugh.gif That pic. really cleared it up for me. No wonder I couldnt find it! Thanks, Ron  

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Modding the IDM on a 7.3

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Nice writeup Evan....can't wait to hear about the dyno and what if any improvements are noted.  

Any dyno results yet?  

Can this be done to the obs trucks? Thanks Ryan.  

DieselWrencher1 said: Can this be done to the obs trucks? Thanks Ryan. Click to expand...

racehauler said: Any dyno results yet? Click to expand...

Just another update: I was shut out of the dyno day on Saturday so I'll have to make an appointment with my local dyno to get it tested.  

i never picked the resistors by the IDM model numbers, always by the part numbers. what part number is your IDM? the first 4 numbers/letters. idm mod was always good for 45hp/100 ft-lbs. the smaller resistor will make less power, slightly.  

I should have looked at that, Joe. But I didn't think about it since I was going off of the info on the other site. Is there any safety factor to going with the smaller resistor across the board? As far as not pushing the other components closer to their limits?  

what kind of resistor should i use for mine i have a OBS truck and i whant the maximum out of this mod. does it make the truck smoke any?  

Has anybody ever repaired the IDM? There is a video on the internet but does not mention the component values. I just got a van now and migh need to fix mine. 7.3 97  

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Ford 7.3L Injector Drive Module (IDM) Operation

The Ford Power Stroke 7.3L engine has established its legacy as a reliable and stout diesel engine. Over two million of the engines were produced from 1994 through 2003. It was replaced with the 6.0L Power Stroke engine in 2003 because it could not meet new federal emission standards.

Because of their proven track record as being a solid long lasting engine, the repair market for the Ford Power Stroke 7.3L engines is quite healthy. As with any high production vehicle, problems can and will occur. One area for potential repairs is the Injector Driver Module, or “IDM”.

The 7.3L utilizes Hydraulically actuated Electronically controlled Unit Injectors, commonly referred to as HEUI or “HUEY” injectors. These injectors utilize high pressure oil which is controlled by a poppet valve inside the injector to achieve injection pressures of up to 21,000 psi. The poppet valve operation is electronically controlled by an injector mounted solenoid.

Because of the high pressures involved, the solenoid-operated poppet valve requires 115 volts at up to 8 amps to operate, which is more power than the Powertrain Control Module (PCM) can provide. Because of this, the injectors are directly controlled by a separate control module called the Injector Driver Module (IDM). The IDM provides the high voltage and switching signals to turn the injectors on and off.

The IDM and PCM work together to control the entire fuel system (see Figure 1). The PCM receives inputs from numerous sensors then transmits injection timing signals to the IDM module, which then carries out the activation of the injectors.

Injector Power & Ground

The injectors are grouped into two banks of four injectors each. Each bank shares a common power feed which is generated by the IDM. The voltage supplied to the injectors is 115 volts DC and is only activated when one of the injectors is firing.

The injectors have 8 individual ground circuits. An injection event occurs when the IDM supplies power to the bank for the injector to be fired while simultaneously grounding the desired injector's ground circuit. The pulse supplied to the solenoid is typically between .5-2.0 milliseconds.

Injection Fuel Volume

Unlike gasoline injectors or other electronically controlled diesel injectors, the fuel volume is not controlled by the pulse width that is supplied to the injector. Instead, fuel volume is controlled by the oil pressure supplied to the injector, referred to as the Injection Control Pressure (ICP).

Oil pressure is supplied to the injector by a mechanically driven injection pump (A) at pressures of up to 3,000 psi. The injector is also supplied fuel at approximately 40-50 psi (B). Separation between the fuel and oil is accomplished with internal and external o-rings.

When the solenoid is activated the high pressure oil is supplied to the top of an internal intensifier piston, which acts upon a fuel plunger causing the fuel to be injected. The intensifier piston has an area that is seven times larger than the fuel plunger. Because of this, the pressure on the plunger is amplified to achieve injection pressures of up to 21,000 psi.

The Injection Control Pressure (ICP) is closed-looped controlled by the PCM. The PCM monitors the ICP Sensor (C) and modulates the ICP Regulator (D) to achieve the desired control pressure for the current operating condition. The fuel volume injected is directly proportional to the injection control pressure. The PCM monitors numerous input sensors to calculate the fuel demand including the Accelerator Pedal Position sensor, Engine Coolant Temperature sensor and Manifold Absolute Pressure to name a few.

Injection Timing and Synchronization

In order for the IDM to synchronize the injection events to crankshaft position it must communicate with the PCM.

The PCM generates two digital control signals for the IDM: the Fuel Delivery Control Signal (F) and the Cylinder Identification (G). The FDCS signal is used by the IDM to control injection timing and duration. The CID signal provides synchronization to the engine's first and fifth injector.

Cylinder Identification Signal (CID)

The PCM receives engine rotational position information from the Camshaft Position sensor (CMP). The CMP (E) is a hall-effect device. It outputs 12 volts to the PCM whenever it detects the iron of a spoke on the target wheel in front of it. It outputs 0 volts whenever it detects the space between the spokes. The target wheel spokes and spaces are each 15 crank degrees apart, except for narrow spoke which indicates cylinder number 1 and a wide spoke which indicates cylinder number 4 (fifth in firing order).

The PCM receives the Camshaft Position signal and transmits a modified signal (G) to the IDM that indicates which injector bank should be firing. Bank 1 consisting of cylinders 1, 3, 5 and 7 is located on the passenger side while bank 2 consisting of cylinders 2, 4, 6 and 8 is located on the driver's side. The IDM uses this signal to determine which high side driver should be switched on.

Fuel Delivery Control Signal (FDCS)

Actual injector timing and duration is controlled by the Fuel Delivery Controlled Signal. The PCM generates and transmits a pulse for each injection event (F) to the IDM. The IDM uses this signal to turn on the proper low side driver for the injector being activated.

The IDM is programmed with the firing order of the vehicle. Using both the CID and FDC signals from the PCM the IDM provides precise synchronization of injection events to piston position.

Self Diagnostics

The IDM monitors the injector switching circuits and can transmit diagnostic information to the PCM if it detects a fault (H). The PCM will store a Diagnostic Trouble Code (DTC) specific to the type of failure, which can be retrieved using the appropriate diagnostic equipment. There are numerous diagnostic codes related to the IDM so consult the vehicle specific service information for a definition of each code.

Failure Modes

The IDM module is mounted in the engine compartment and due to its location is very susceptible to water damage. Water intrusion takes place through an air vent that is an integral part of the IDM case. Once water enters the module, failure is eminent and usually results in a no-start condition. On units remanufactured by GB the vent has been redesigned to prevent this type of failure.

Another failure mode is the result of failed wiring between the IDM and the injectors. The fuel injectors on the 7.3L are located under the valve covers. Because of this, the wires for each bank of injectors pass through connectors that are molded into the valve cover gaskets. The wiring on the inside of the valve covers are constantly exposed to hot oil. Over time these connectors can become brittle and crack causing the wires to short together causing IDM failure. This type of failure must be diagnosed PRIOR to replacing the IDM; otherwise failure of the replacement module will result. Additionally, these poor connections can be intermittent so a visual inspection and electrical test is recommended prior to condemning or replacing an IDM. Intermittent connections can be difficult to diagnose and can result in intermittent injector fire either on a single injector or an entire bank. Failure to locate this type of failure can result in costly warranty come-backs. In order to properly inspect the wiring to the injectors the valve covers should be removed. It is a best practice to replace the valve cover gaskets when reinstalled if they are the original gaskets. GB has published Tech Bulletin TB#103 that details the tests that should be performed prior to replacement. The bulletin can be downloaded here .

Replacement Tips and Warnings

The actual replacement of the IDM is not technically challenging, however proper diagnosis to eliminate damage to the new IDM is critical. Here are some tips that can help:

Check for Diagnostic Trouble Codes (DTC). Follow the appropriate service manual tests for each DTC retrieved.

Perform a thorough visual inspection on the wiring between the IDM and the injectors. Flexing and wiggling the wiring harness can detect some faults and should be performed during the pin point test detailed in TB# 103.

Inspect the connectors at the valve cover gaskets both on the inside and outside. Make sure the connectors, wires and seals are not broken or soft.

Inspect the outside of the IDM. If there is corrosion present or the paint is peeling off, chances are the IDM has internal water damage. If the aluminum vent cover is missing then water damage is highly probable.

Use caution when working on the IDM system. High voltage is present on the injector wires when the engine is running (115 volts). These wires are shielded and piercing the wires will result in wiring harness damage not to mention personal injury.

GB offers two part numbers to cover all 7.3L Power Stroke applications from 1994 through 2003. 1994-98 model years use part number 921-110 while 1999-2003 utilize GB part number 921-120. Another quick way to identify the IDM is by color. If the OE module is silver or bare aluminum it is the early module (921-110) while the 921-120 version is black.

GB also provides rebuild & return (R&R) services for customers. Please contact us for more information.

Curious to learn more? Visit our Knowledge Center , packed with fuel injection-related articles and topics to assist you in better understanding fuel injection systems and technologies.

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6 Symptoms to Detect IDM Failure On a 7.3L Powerstroke

The main task of IDM in your 7.3 Powerstroke’s engine is to send high voltage signals to the injectors. 

It is a dumb part with one function and you can interchange the part regardless of engine model. 

And, you have guessed it right. IDM can also go bad like other parts. Let me enlighten you by telling you the 7.3 IDM symptoms and signs in detail. 

Signs of A Bad 7.3 IDM 

Stalling and sudden loss of power while running is the main sign of having a bad 7.3 IDM. 

But the list of signs and symptoms does not end there. Read the next part to get a clear picture.

6 Symptoms Of a 7.3L Powerstroke IDM Failure:

Know how to detect a bad 7.3 IDM by reading the symptoms explained in this part without skipping. It can save you a lot of trouble.

1. Running Problem

Lots of truck owners complained that they were having issues while driving the truck. 

All of a sudden, it stalls and starts right back up. You may think that the CPS has gone bad. 

But that might not be the case. If you pull the error codes, you will get something that indicates a bad IDM.

Corrosion or something else can damage the module. The quickest to confirm it is by looking at it. 

2. Power Loss

Another common symptom of having an improper-functioning injector driver module is experiencing random cutouts and sudden loss of power.

Those who don’t have the necessary rig to see the error codes should take their truck to the nearest servicing center. 

Sometimes, the tech can’t pull out the code due to various reasons. In that case, tell your mechanic to do a manual inspection. 

Owners described the situation in some forum discussions. The engine shuts down and restarts while running at full speed. 

So, you can understand that this is not an issue to be taken lightly. 

3. Running Rough

Some of you may not experience any of the symptoms mentioned above. The engine won’t shut off in the middle of anywhere.

But it can run rough without good reasons. You won’t see other components acting badly which are typically responsible for rough running. 

After doing a complete scan of the engine, it will probably show error code p1316. And, one can be assured of having a faulty IDM.

On the other hand, it is possible that the IDM is fine even though the error code clearly indicates that. You should also check the oil and see whether you have put too much.

Read Also: How To Test 7.3 Powerstroke Glow Plugs? (Step By Step)

4. No Starting at All

In some cases, a bad IDM keeps the engine from starting. Because the role of this module is to send high voltage signals for injectors.

And, failing to send the signal stops fuel from going into the cylinders which are necessary for ignition. 

5. Multiple Problems

I have come across a thread in The Diesel Garage forum where one user mentioned facing several issues. 

And, it all indicated a bad IDM. Let’s talk about what those are. 

First of all, the truck owner experienced knocking and shaking on a regular basis. It happened when the throttle was depressed. 

However, there were no signs of engine light or DTCs. Even the injectors turned out to be working fine after an injector buzz test. 

Interestingly, a cylinder contribution test revealed that a few cylinders were not getting enough fuel. 

One way to find out the problem and solution, you can interchange the IDM with another truck, and go for a test drive.

6. Error Codes

The final symptom I am going to tell you involves regular checkups or inspections. 

While doing a full computer scan of the system, you may get the error related to the IDM problem. 

I have already mentioned one. You should occasionally run it by your mechanic because he/she would know which ones are concerning. 

Pro Tip: As Injector Driver Module or IDM can go bad due to water damage, you should check for non-functioning wire, moisture, or traces of water. So, deal with it according to your inspection. If it doesn’t solve the issue, you will have to replace the whole module.

Read Also: Common 6.7 L Powerstroke Transmission Problems and Solution

What to Do When You Detect A Bad 7.3 IDM?

Once you have confirmed that the IDM is causing all the problems, you can take it to a mechanic. 

As it is a PCB board with some electrical components, it is possible to repair it.

If the module is beyond repair, you can replace it without much hassle. The procedure is simple, and you can take help from the steps below. 

• Locate the module inside the hood. You can find it on the driver’s side fender.
• Take off all the screws, and take out the circuit.
• Now, repair the circuit if possible. Otherwise, replace the whole unit with a new one.

Read Also: Symptoms To Detect A Bad VGT Solenoid On 6.0 L Powerstroke

Is Replacing A Bad 7.3 IDM Typically Expensive?

Yes, you can say replacing a bad 7.3 Injector Driver Module is expensive. The best deal I could find on Amazon costs less than 350 dollars.

No expert help is required to replace the module. So, you won’t have to factor in the labor cost of your mechanic.

Read Also: Common 6.0L Powerstroke Transmission Problems With Solution

How Often Should You Inspect 7.3 IDM?

The sealed box performs without any major issues for years. Yet it can go bad for water intrusion. 

Inspecting the inside of the module is not logical. So, service, repair, or replace it once you experience one of the signs and symptoms described above. 

Also, make sure that the module itself is faulty before deciding on buying a new one. 

It is because those symptoms can be triggered by other faulty parts of the engine too.

Being able to recognize the symptoms of IDM (Injector Driver Module) failure in your 7.3L Powerstroke engine is crucial for its proper functioning. If you experience issues like stalling, power loss, rough running, or error codes, it’s essential to consult a mechanic for diagnosis and potential replacement. While fixing a bad IDM can be costly, it’s an investment in your engine’s longevity. Regular inspections are key, but make sure the IDM is the actual problem before taking action, as other issues can mimic these symptoms. Stay proactive to keep your 7.3L Powerstroke running smoothly.

Read Also: 7 Symptoms To Detect A Bad MAP Sensor On 6.0 Powerstroke

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2002 7.3 clicking idm relay no start

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Hello would love some help.Went out to fire up my truck really cold out almost started but was cranking really slow then idm relay started clicking and glow plug light wont go out.Have charged batts checked voltages and checked all grounds,harnesses,connections and fuses switched relays.Cranks over good now but relay wont stop clicking sounds like fuel pump isnt running either is it poss I fried my pcm with a hard cold weather start seems like pcm isnt giving idm relay signal to activate.Been checking connections and plugs relays, fuses, harness etc for 2 days anyone else had a pcm fail and cause this?  

Have you looked at THIS Connection? http://www.powerstroke.org/forum/99...sion-if-your-truck-like-mine.html#post1343921  

Yes I have mine was clean but i took it apart and cleaned it in hopes but no luck  

Also should let know my scanner will not communicate and i have checked all fuses  

Do you have a WTS light when you first roll-on the key? If not, that's a good indication your PCM isn't getting power and, in the winter is often caused by the fuel heater (#30) fuse popping because it's shorted out. You could just unplug the heater if that were the case....  

It's fuse #22, (30 amp maxi fuse):thumb:  

All my dash lights are working the glo plug light just stay on thou doesnt shut off  

Yea my wait to start light comes on but it doesnt time off the light stays on along with idm relay clicking rapidly.Think i may trying kicking and spitting at it next lol.My buddu has a 99 i may try his pcm in my truck but i already know its not going to be the right pcm for my truck so im a little scared to try it in the case i fry his pcm.  

my 99 f-350 is doing the kind of the same thing. everytime i put the key forward it blows my #30 fuse which would be the fuel heater. not sure what is wrong with it... need some help  

The heater is shorted. Disconnect the heater and replace the fuse.:thumb:  

do i just disconnect it then connect it again? or leave it disconnected?  

Leave it disconnected. You don't need it.  

alright. thanks. one more question. would that be the same thing as the block heater or whatever? like the connector it has in the front? or is that a different deal?  

I always get the plug confused. It doesn't look anything like the block heater plug though. I think it is at the bottom of the fuel filter bowl on the drivers side of it.  

alright sounds good. ill try that in a few and hopefully it works! haha. Thanks man!  

No problem:thumb:  

it works! haha thanks again  

Good deal:thumb:  

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IDM Module location??

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I looked around here and could not find a thread on it. CAn someone tell me where the IDM is? And what it looks like? It is on a 2000 reg cab 4X4 with a 7.3 Thanks in advanced. Later Cruz  

behind the drivers side front fenderwell  

Its actually inside the driver side fender. If you could cut out around the F-x50 badge you would see it. To get at it you have to remove the screws/bolts holding the inner plastic fender liner, pull the liner down, then you can see it. Can't remember how many bolts hold it in, but I think just one. Should be around 11mm. Peter  

Looks sorta like your PCM.  

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