Cummins P1693 Engine Code – Diagnosis & Troubleshooting

What is P1693 on a Cummins?

If you Google P1693, you will probably see something that reads “Turbo Charge Control Circuit Malfunction”. However, on Cummins turbo diesel engines, this code has nothing to do with the turbocharger. 

P1693 is considered the “companion code”. It is triggered when the powertrain control module (PCM) detects a code that us not actually associated with the PCM. Usually, the code is related to the ECM, or the engine control module. So it’s referred to as the companion code because it essentially just notifies you that there is an issue and that another code is stored in the car.

This code solely lets you know that at least one trouble code is stored within the PCM or ECM. Again, it does not indicate and turbocharger related issues! Long story short, P1693 on a Cummins engine means you need to plug an OBDII scanner into the car to read the real code.

Causes of Cummins P1693 Trouble Codes

Because the code essentially means you have a separate code related to the ECM, anything can cause this technically.

However, a majority 5.9 24v owners who experience P1693 later claim that it was a fault associated with the VP44 fuel injection pump. If this is the case, when you scan the car with an OBDII scanner, you will receive a P0216 engine code. If you have a common VP44 failure, you will notice these symptoms:

  • Poor idling and performance
  • Engine misfires
  • Engine no start or hard start
  • No starts when engine hot but no starts when cold
  • Engine cuts off while idling or driving

Additionally, another common cause of P1693 on the 24v is the Accelerator Pedal Position Sensor (APPS) failure. This failure, which you can read about it our 5.9 common problems post is caused when the gas pedal sensor fails essentially rendering the pedal useless, which can create erratic and scary driving conditions.

How do I determine the actual problem, then?

You will need to get an OBDII scanner and plug it into the car to read the actual code. We recommend this scanner: ANCEL AD310.

If you don’t want to spend $35 or wait two days for it to show up, Autozone, Oreilly’s, etc. will read the code for you for free. However, we recommend buying one and always keeping it in your glove box as it’s super handy. Depending on what the problem is, it might not be smart to drive your truck to an auto parts store.

Although rare, it is possible to get a P1693 code on your Cummins and actually not have anything wrong with it. A temporarily faulty electrical connection or a blown fuse could set the code off when there is really no trouble code in the ECM.