4 Possible Causes To P1689 Code Cummins and Their Quick Fixes

What is p1689 code Cummins? It indicates there’s a problem with the fuel injector that ECM can detect in your vehicles.

When the ECM recognises a problem with the carburettors, it sets this code. But, do you understand exactly how to repair it?

However, for your convenience in this article, we will briefly discuss the symptoms, the underlying cause, and possible solutions to make troubleshooting easier for you.

P1689 Code Cummins

p1689 code Cummins is an error code that is probably generated because of a physical defect or by applying a due voltage to a secondary circuit.

Although there are certain treatments for a p1689 code Cummins lit problem, it is not always easy to pinpoint a defective part.

Look at the chart below reveals the most likely causative factors for the p1689 code Cummins.

Low fuel pressureThe engine misfiring.
Fuel filter congested or restrictedBad acceleration
Fuel injector malfunctioningRough running
Fuel pump malfunctioningNo engine power

Meanwhile, let’s explore each of the most significant p1689 code Cummins causes and their straightforward solutions.

Low Fuel Pressure

There is a lot of trouble with diesel fuel when low fuel concentration. Congested propellant filters, limited fuel levels, a crappy fuel compressor or a malfunctioning sensor, are all possible causes of this problem.

Solution: To troubleshoot, first and foremost, check the fuel pump tray.

Fuel Filter Congested

Dust particles accumulate in the carburetor and cause it to clog. Having blockage air or fuel filters can make it hard to get going quickly.

Furthermore, a clogged air purifier can cause an unpleasant smell to propagate throughout the vehicle and make it difficult to initiate. Otherwise, if you look for the p1689 Cummins no start symptom, you can also find this trouble code.

Solution: To get rid of this code,  clean the dirt and debris and clean the fuel filter.

Fuel Injector Malfunctioning

The fuel injector is a device that sprays an extremely fine mist of liquid fuel into the air in the intake manifold of each cylinder. The fuel mist is ignited by the spark plugs powered by the engine’s ignition system. The combustion process that follows forces the piston downward, turning the crankshaft and eventually spinning the wheels.

When the injector malfunctions, it will not be able to provide the correct amount of fuel to the engine, which can cause poor performance and damage to other parts of the vehicle.

Solution: The solution to this problem is to replace the fuel injector If you can be able to solve this issue, you will find your p1689 Cummins runs fine.

Fuel Pump Malfunctioning

A fuel pump malfunctioning is a problem with the pump that pumps diesel from the tank or reservoir into the engine. The pump may not be able to provide enough pressure for adequate fueling, or it may stop working altogether.

Solution: To begin, look for a malfunctioning fuel pump position. However, you may find it inside or outside of the engine compartment. Sometimes, it can mount on a bracket near one or more injection pumps. You can use a fuel gauge or replace the pump with a new one.

This Video Will Help You Too!

Frequently Asked Questions (FAQs)

What causes p1689 ?

There could be leakages or problems with the fuel injector, which could end up causing P1689. On the contrary, a bad fuel injector can harm other components of your car. For example, the engine, transmission, or drivetrain. Moreover, dust particles also accumulate in the inlet side, which makes the propellant drop in pressure.

How do I fix p1689 code?

In order to fix this error, make sure to make a list of all issues for replacement. Then, swap with a new one or substitute the ignition or fuel tank. Next, start replacing the malfunctioning compressor. Remember in mind that there is no long term solution at home. As a result, we recommend that code P1689 you may repair by a professional.


In order to fix it, regardless of the type of vehicle you own, you must resolve the fault p1689 code Cummins issue. Fixing the error code can be challenging, especially if you are unfamiliar with the causes of this error code. When it comes to fuel-related causes; otherwise, it will harm your vehicle’s other components very soon.

This error code has 4 possible reasons, each of which has a fix. We’ve put together a list to assist you. There’s a good chance that you now know how to fix the P1689 error code Cummins.

You Can Also Read:

D Conroy

Meet our senior writer and content manager of Automasterx. He has worked in several mechanical garages and mastered different vehicle diagnoses and parts repair. He never stops until finding out the ultimate solutions for any vehicle fault code. However, ensuring the only solid solutions for each vehicle malfunction is his core part of the duty, alongside analyzing fault codes and signals.

Similar Posts