What Is Fault Code SPN 3464 FMI 16? (Detroit, Cummins)

With all the new regulations that have been implemented since the late 1990s, more parts have been invented. More parts mean more possible failures and more fault codes to learn.

The SPN 3464 FMI 16 fault code stands for “Intake Manifold Pressure Over-boost Detected During a Regeneration”. You should see the CEL and the MIL warning lights illuminated when this code is set. Unfortunately, there are 34 steps you may take to resolve this code.

To learn more about this fault code, what it means, and how to fix it, just continue to read our article. It has the information you want to know about so that you can make the right repair without too much delay. Keep reading to get all of this important information.

What is SPN 3464 FMI 16?


Sometimes your code reader may make this display- “ Engine throttle Actuator 1 control command” but that may not be accurate. According to the data sheet on this code, the real problem is “Intake Manifold Pressure Over-boost Detected During a Regeneration.”

For Cummins the first definition is correct and it is supposed to be Cummins Fault Code 5882 but it is not listed on the comprehensive fault code sheet. For this motor the full definition is:

Electronic Throttle Control Actuator - Mechanical System Not

Responding or Out of Adjustment” What you may experience will be some of the following signs:

- Restricted engine intake throttle

- Engine intake throttle actuator motor open circuit check

- ECM calibration revision history check

- Engine intake throttle actuator not responding or out of adjustment

Each one of these symptoms will have its own repair guide and you should inspect the engine intake throttle for restriction, stuck or debris blocking the throttle plate. The fix is simple, just remove the restriction or blockage.

The validation for this particular problem is as follows:

- Connect all components

- Connect the recommended Cummins® electronic service tool or equivalent.

- Disable the fault code.

- Operate the engine within the "Conditions for Clearing the Fault Code" found in the Overview section of the troubleshooting procedure.

- Verify that the fault code is no longer active.

- Check ECM Calibration Revision History

- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.

- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.

- Refer to ECM Calibration Revision History Database

The rest of the repairs for the other 3 symptoms and their validation can be found

at this link.

Detroit SPN 3464 FMI 16


This code for the Detroit Diesel engines is slightly different than for the Cummins engines. The definition for this particular application is- Intake Manifold Pressure Over-boost Detected During a Regeneration.

As usual, the first step will have you fix any related codes first before working on this one. Once that is done you have to check the MCM and see if it is updated or not. If not, you need to update it first before moving on down the line.

Whether it needs updating or not, the next step for both options is to go to step #4. This can be a long process if you do not find the source of the problem soon. There are a total of 34 steps you may eventually have to take to completely resolve this problem.

It is possible without going through all those steps, that the problem lies with the IMAP sensor. It may need to be replaced and you may have to do either a passive regen or a manual one to make sure the fix worked.

Here is the crux of the issue, it seems that this problem may trigger the dashboard warning light but nothing happens to performance and no derates ever take place. Some people have replaced this sensor and after 50 miles, the light returns.

However, one owner has driven roughly 200,000 miles with the light on and nothing has happened so far. You could replace the MCM but that is spending $2000 to turn off a light. This may be one of the steps you have to take eventually but nothing bad may happen for a long time.

IMAP sensors are said to fail around 100,000 miles or so and this may be the most common reason for this code.

SPN 3464 Engine Throttle Actuator 1 Control Command


The complete information for this code is “Intake Manifold Pressure Too High Due To Wastegate: Engine Throttle Actuator 1 Control Command Data Valid But Above Normal Operating Range - Moderately Severe Level; Itv Pressure High Monitoring”

Unfortunately, there is no new information than what we have already linked above. The last step of the repair guide has this to say:

Install original MCM. Bring to operating temperature of 71°C (160°F). Road test the vehicle. Drive at highway speed with loaded trailer above 1130 rpm continuously for five minutes. Does fault become active?

a. Yes; replace turbocharger.

Refer to section "Removal of the DD13 Turbocharger".

Refer to section "Removal of the DD15 and the DD16 Turbocharger".

b. No; replace the MCM. Refer to section "Removal of the Motor Control Module".”

It seems that replacing the MCM is the last ditch effort to resolve this problem and be able to clear this code. Other similar codes talk about how the desired throttle position does not match the actual throttle position and a code is set.

You are going to get a lot of confusing information when you do your own research on this code. It is best to talk to a qualified mechanic to make sure you get the right information so you get the problem resolved correctly.

SPN 3464 FMI 7


According to the official SPN code list, this is what this code stands for- “Intake Throttle Valve, Stuck: Engine Throttle Actuator 1 Control Command Mechanical System Not Responding Or Out Of Adjustment; Stuck”

Unfortunately, the official list is just a list for definitions so you understand what the code is saying. It does not provide any further information on this problem.

This would relate back to the data sheet we linked to earlier. There may be something blocking the throttle or valve and you just need to look to see what that blockage is. Then just remove it. No special tools are needed for this repair.

Or it may be an electrical problem that is a little harder to diagnose and repair. You would have to spend time inspecting all the wires, the harness, the pins, and the connectors to make sure they are not damaged in any way.

Then make the necessary repairs. You will have to measure the resistance on these components as well. If you have an owner’s manual you will need to refer to the wiring diagram to make sure the diagnoses and repairs are correct. It may end up being the wiring harness has gone bad.

SPN 3464 Fail 31


This code has three possibilities and they are: H Bridge 1 Iat Circuit Open Load; H Bridge 1 Iat Circuit Open Load: Engine Throttle Actuator 1 Control Command Condition Exists; High Bridge 1 Open Load, and Intake Air Throttle Control Electrical Fault.

The valve is supposed to open and close with the key turned on. When it does not do that you should see this code. This code is not related to any sensor that we are aware of.

The fix is going to be to replace the intake throttle valve on the air intake. This is not a cheap repair but it is less expensive than many other repairs you could do on your engine.

Depending on who you use to do the work parts and labor run between $500 and $700. Unfortunately, this is a common failure for these types of engines. The part is not that strong it seems and mechanics see this repair more often than they would like.

The correct term for this code is as written in the sub-heading. There was no typing error made. The code we gave is for this failure and it is written as SPN 3464 FMI 31. Codes do get confusing from time to time.

Some Final Words

No matter what engine brand or model you buy, you will always face these codes. This has been the way it is for almost 30 years now. The best thing to do is to print out the different code lists so you understand what the problem is before you go to the mechanic or dealer.

Sadly, not every mechanic or dealer is honest and you need to double-check what they tell you. The more complicated the engines get, the more chances they have of adding repairs to your bill. Protect yourself by knowing the codes.

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