What Is P1670 code on 7.3 Powerstroke: How To Fix?

Ford 7.3L Powerstroke tells users about engine difficulties through DTCs (Diagnostic Trouble Codes). The P1670 code is one of these trouble codes.

If you’re getting the DTC P1670 & don’t know what it means, this article is for you. I’ve discussed everything from symptoms to solutions in this article.

P1670 Code On 7.3 Powerstroke

What Does P1670 Code Means On 7.3L Powerstroke? 

P1670 is one of the diagnostic codes of the Ford 7.3L engine. By definition, the error code P1670 refers to Electronic Feedback (EF) Signal Not Detected. 

The PCM (Powertrain Control Module) communicates with the IDM (Injector Driver Module) through EF or Electric Feedback. When the PCM is unable to communicate with the IDM, it generates the DTC P1670. 

Communication between PCM and IDM is essential for various purposes. If it’s disconnected, you’ll face several problems & I’ll discuss them in the symptoms section. 

Symptoms Of Getting The P1670 Code On A 7.3

Just like any other DTCs, the trouble code P1670 comes with a few visible symptoms. Suspect to have this error code if you’re noticing the following symptoms: 

  • Service Engine Soon Warning Light is On
  • Irregular Revolutions Per Minute (RPM)
  • Engine Won’t Start At All 

They are the few symptoms you may see if you’re getting the code P1670. 

The Causing Factors Of The Error Code P1670

The Error code P1670 can appear for many reasons & sadly, you can’t do anything as prevention. Majority of the causing factors are related to the IDM, such as: 

  1. Damaged Injector Driver Module Relay
  2. Shorted or Open Injector Driver Module Enable Circuit 
  3. Short or Open in Electric Feedback Circuit
  4. Short or Open in FDCS (Fuel Delivery Command Signal) Circuit
  5. Short or Open Fuses
  6. Damaged Injector Driver Module 

Though I only mentioned six causing factors, don’t be very happy if you’re not getting all of them at once. Even one of them is enough to bring up the code P1670. 

How Seriousness Is Code P1670 On 7.3L Powerstroke 

The RPM or Revolutions Per Minute indicates how fast or slow you’ll go. As you’ll be getting irregular RPM, this code must be affecting your engine. 

That’s why you shouldn’t bet on your engine ignoring this error code. Follow the next segment to know how to fix P1670 on 7.3L Powerstroke. 

How to Solve P1670 Error Code On 7.3L Powerstroke?

Make sure to have the necessary equipment according to your engine model. You’ll have to open wirings, connectors & even the IDM to solve this error code. 

Considering you’re ready with your equipment kit, let’s get started with the troubleshooting methods: 

Replace IDM Relay & Fuses 

Relay helps with automating connections between two components. They act as an electrical switch that can function on their own. Check the IDM relays; they might be faulty. If so, replace them with new relays. 

Automotive fuses are the self-destructive protectors of any wirings & connectors of vehicles. Maybe your ford 7.3L encountered an over-current issue that damaged the fuses. Replace the fuses & the error code should be solved. 

Clean & Replace All Wirings

Under the hood, you’ll find several wirings & connectors related to the Injector Driver Module (IDM). If you see any inconveniences, replace them. 

Most of the time, code P1670 occurs due to shorts in the wiring. As they are cheap, you can easily replace every wiring & connector with ease. 

Perform KOEO Self-Test For Other Codes 

You might be having more IDM codes besides P1670. To know whether you have more codes, you’ve to perform a KOEO (Key On Engine Off) Self-Test or Buzz test. 

If you’re getting more trouble codes from your IDM, consult any experts to deal with your issue. Sometimes, IDM issues result in defective PCM as well & you shouldn’t take that risk. 

Check & Replace The IDM 

The ultimate solution of the error code P1670 is to replace the IDM. If you see the DTC P1298 after KOEO Self-Test, replace the IDM as it refers to defective IDM. 

Even if you don’t have any other code other than P1670, you can still replace the IDM if none of the mentioned methods are working. 

How Much Does It Cost To Solve The Error Code P1670

The cost depends on how many components you’re replacing to solve the error code P1670. For your easier understanding, here is the price list of potential replacements:

  • Automotive Fuses: $110 to $140
  • IDM Relays: $30 Each 
  • IDM: $250 to $400

You can add the labor cost of $75 to $150 per hour if you don’t want to mess with the error code on your own.

Common Mistakes While Solving The P1670 Code

It’s possible to commit mistakes while solving the P1670. Still, consider double-checking these common mistakes mentioned below: 

  • Not Checking The Wirings Before Replacing The IDM
  • Not Conducting KOEO Self-Test For Better Diagnosis

Additional Comments To Consider Regarding The P1670 Code 

You may not see any symptoms besides the active engine light. That doesn’t mean you should ignore this error code. Doing so can lead to even bigger problems for you (financially) & your engine. 


I hope this article was informative enough to know the error code thoroughly. Now you know the possible symptoms & causes of the code P1670. 

P1670 is user-friendly, meaning the general user can quickly solve this code. Still, don’t hesitate to get expert help if you’re having issues solving on your own.

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