How to Fix the P1193 Code 6.7 Cummins – With Diagnosis!

The Check Engine light is on! On top of that, OBD sends you an error code- P1193! Should you be worried? 

What does the P1193 code 6.7 Cummins mean?

The P1193 code means the IAT sensor of the engine has more than 4.9 voltage. It indicates an anomaly in the sensor. Possible reasons for this code include malfunction of the sensor, wear or tear of the harness, and problematic PCM. You need to troubleshoot all relevant components for a solution.

Be with me till the end of this article to understand everything about the P1193 code. I will tell you how to detect, diagnose, and resolve the error code most efficiently.

What Does P1193 Code in 6.7 Cummins Mean?

The P1193 code in 6.7 Cummins indicates that the IAT sensor has gone bad. It is alarming because the system cannot detect the density of the air the engine intakes. It fails to supply the right amount of fuel. So, the performance and longevity of the engine will deteriorate.

The P1193 code is generated from the self-diagnostic system, On-Board Diagnostics or OBD. The OBD constantly communicates with all the control modules of the vehicle to learn about any anomalies. For example, the control module to operate the engine is the Powertrain Control Module or PCM.

The PCM checks the temperature that enters the engine using the Intake Air Temperature or IAT sensor. By analyzing the air temperature, the PCM can know the density of the air. This procedure is very crucial for engine performance.

Depending on the air density, the PCM injects the right fuel into the engine. The PCM checks the health of the IAT sensor by detecting its voltage level. The PCM senses a fault when the IAT has more than 4.9 voltages.

Then, the PCM communicates with the OBD and tells it about the problem with the IAT sensor. Consequently, the OBD generates the code P1193 and sends it to you. Each of the letters of the code has a message for you. Now, let us break down the code to understand it better.

The letter P of the code tells us that the stress signal came from the PCM. So, the problem is related to the engine. The first digit of the code further specifies the area of the problem. Here 1 indicates the fuel and air metering area of the engine.

The second 1 of the code tells us that the system pressure is high in that area. And the last two digits denote that the IAT has a higher voltage than usual.

So, the P1193 code wants you to troubleshoot the IAT sensor of the engine for any fault.

How Severe is The Problem?

Your vehicle may act unusual if you take it out without solving the P1193 code. Moreover, the driving experience will not be as smooth as it used to be. For example, you may experience sudden engine stalling and hard starts in cold weather.

Besides, accelerating the vehicle can be difficult. Hence, the risk of accidents rises. You will also notice a deterioration in fuel efficiency.

More importantly, you are risking the longevity of your engine by driving with an unresolved P1193 code. The engine uses a delicate ratio of fuel and air to make perfect combustions to generate energy.

When the IAT is non-functional, the engine does not get the right fuel. As a result, different engine parts lose longevity.

What Are the Common Symptoms of The P1193 Code?

You can sense a problem with the intake air temperature sensor even without getting the P1193 code. So, what are the symptoms of faulty air intake? 

Check Engine Light, acceleration problems, and less fuel efficiency are common symptoms of a faulty air intake. Moreover, you may hear a rattling engine sound.

The symptoms are described below.

• Check Engine Light is On: The Powertrain Control Module will turn on the Check Engine light. The PCM does so even before sending distress signals to the OBD system.
• Problems in Acceleration: You will feel a sudden lack of acceleration in your vehicle. If you are a regular driver, you will know the difference. Pressing the gas pedal hard will become less rewarding for you. 
• Engine Stalling: You will know that the engine has stopped working suddenly while driving. It can also happen when you try to accelerate by pressing the gas pad. 
• Loss in Fuel Efficiency: When the IAT sensor fails, the PCM cannot provide the right fuel. As a result, a good amount of fuel is wasted. Hence, you notice less fuel efficiency in your vehicle.
• Noises: You will probably hear a constant rattling sound from the engine. Remember to check the IAT sensor next time you hear that.
• Difficulty in Cold Starts: Starting your vehicle in cold weather becomes challenging when the IAT sensor malfunctions.

How to Diagnose the IAT Sensor for P1193 Code?

The P1193 code only tells you about a high voltage in the IAT sensor. However, it can happen for many reasons. The right way to deal with the problem is to know the exact problem first.

Here I listed the steps you need to take to know the reason for the P1193 code. Please do not ignore the sequence of the diagnosis process.

Tools Required

Our diagnostic procedure does not require any sophisticated or expensive equipment. Instead, you can check out the problem using some commonly available tools.

1. A Pan With Water
2. A Stove or induction cooker
3. A Digital Multimeter
4. Long Pliers 

Step 1 of 4: Locate The IAT Sensor

First, you need to identify where the air intake temperature sensor is located.

The air intake temperature sensor is located on top of the air inlet pipe. You will easily find it in your 6.7 Cummins engine right behind the air filter. 

Follow the arrow mark on this picture to know the exact location of the IAT sensor.

Step 2 of 4: Check The Harness

The most common reason for a bad IAT sensor is a damaged harness. So, you need to check it at the very beginning.

First, unplug the harness connector by pressing its tab with your thumb. Next, use a multimeter to check the voltage flow of the harness. Attach the black cable of the multimeter to the engine ground. Put the red cable into the Terminal 1 of the harness connector.

Turn on the ignition key to know the voltage flow in the harness. If the voltage flow is more than 4.9, the harness is the problem. If that is not the case, you need to check the harness further.

Put the black cable into Terminal 2 and see if there is any error beep. An error beep will confirm that the harness of the sensor is just fine.

Step 3 of 4: Check The IAT Sensor

After checking the harness, we will now check the IAT sensor itself. So, how do you test an intake air temperature sensor?

You can test an intake air temperature sensor by checking its ohm readings using a multimeter. Then, you need to change the temperature around the sensor and see if the ohm reading drops. It will drop if the sensor is doing fine. Or, you can use an electronic scanner to know the health of the IAT sensor. 

The process is explained here.

• Step 1 of 3: Remove the IAT sensor from its position to check the sensor without a scanner. 
• Step 2 of 3: Use a multimeter to check the ohm level of the sensor. If the room temperature is around 70°F, the ohm reading should be approximately 2-3 kilo ohms. If you find any other reading in the sensor, it is faulty. 
• Step 3 of 3: Change the temperature around the sensor to see how the ohm changes. Put the pan with water on a stove or induction and turn it on. Hold the sensor with long pliers and keep it over the water pot, as shown in the picture.

If the sensor works well, the ohm reading will gradually drop with the rising temperature. Do not wait till the water boils. It will damage the sensor!

Step 4 of 4: Check the PCM

If you do not find any problem in the sensor harness or the sensor, check the PCM. First of all, check all the connections of the PCM. Look for any loose connections. Then physically check for any rust in the PCM unit.

If they look okay, check the battery of the PCM with your multimeter. See if the voltage level is more than 13.6 with the engine turned on. The voltage reading should be 12 when the engine is turned off.

4 Reasons and Solutions for P1193 Code in 6.7 Cummins

The first step to resolving any problem is to identify the nature of the problem precisely. So, what causes intake air temperature sensor fault codes?

Faulty IAT sensors, harnesses, and PCM can cause IAT sensor fault codes. Moreover, miscommunication between PCM and IAT or any electrical problems can also be a reason.

Reason 1 of 4: Faulty IAT Sensor

The IAT sensor is an electronic component with circuits and different connections. Like any other electric device, it can go bad for little or no reason. The P1193 code primarily identifies the IAT sensor as the root of the problem.

Symptoms

When you have a faulty IAT sensor, you may see the Check Engine light is on. Besides, you may face problems when starting the engine.  Most likely the engine will produce less power and the overall fuel efficiency will decrease.

Solution

The role of the IAT sensor is crucial for the engine. Also, your vehicle’s overall performance and longevity are related to it. So, I suggest replacing the faulty IAT sensor whenever there is a problem.

Cost Involved

The average price for a new IAT sensor is $53. You need to add the labor cost since it should be installed by a professional. The labor cost range to install an IAT sensor is $33-$42. 

Reason 2 of 4: Faulty or Disconnected IAT Sensor Harness

The IAT sensor sends information to the PCM through the harness wires. If the connection between the harness and the sensor is lost, the PCM will not get data. Again, if the wires get damaged, the same thing will happen. As a consequence, the OBD will generate a P1193 code.

Symptoms

You will experience sudden stalling of the engine when the IAT sensor harness has a fault. Besides, the engine RPM will fluctuate unexpectedly while the engine is idle. 

Solution

Check and fix the harness as the process discussed above(Step 2 of 4). 

Diagnose the wires to know if there is any physical damage. Again, a faulty harness may look fine from the outside. Use a multimeter to check its voltage level. If needed, change the harness.

Cost Involved

The price of a new engine harness is $650 on average. However, the cost of fixing the harness varies depending on the model and year of vehicle manufacture.

On average, you may need to spend $1,100 to replace the engine harness. On the other hand, the engine harness’s repair cost can vary from $700 to $1,800. 

Reason 3 of 4: Faulty PCM

The PCM unit controls all engine activities using a complex set of hardware and software. The PCM will not work well if there is a bug or any related hardware malfunctions. And you will get a fake P1193 code.

Symptoms

A common symptom of a faulty PCM is the problematic start of the engine. Besides, you will see the Check Engine light is on for no reason, Moreover, the fuel efficiency will decrease. You may also experience engine stalling from time to time.

Solution

First, check for any physical damage or rust in the PCM unit. Then, check the battery with a multimeter. Use a digital scanner for any bug in the system. Fix or replace the PCM on an urgent basis.

Cost Involved

Replacing a faulty PCM with a new one may cost you from $963 to $1,038. The cost of fixing the PCM depends on the type of problem.

Reason 4 of 4: Communication Problem Between PCM & IAT Sensor

The IAT sensor collects information about the temperature of the air that gets into the engine. This data collection process is analog. The PCM receives these analog data and transforms them into digital data for proper analysis.

The following video explains the relationship between different sensors and the PCM of the 6.7 Cummins.

The process is complex, and the risk of miscommunication is very high. So, a wrong communication between PCM and IAT can also cause the P1193 code.

Symptoms

The PCM will be unable to detect the IAT sensor if there is a complete lapse in communication. On the other hand, the PCM will trigger the wrong error codes if the sensor sends the wrong information.

Solution

Check the PCM and the IAT sensor with a professional to be sure.

Cost Involved

The average price for a new IAT sensor is $53. You need to add the labor cost since it should be installed by a professional. The labor cost range to install an IAT sensor is $33-$42.

Related Article-

1. P1693 Dodge Cummins Troubleshooting; What It Really Means
2. What To Do When You See U010c Code In a 6.7 Cummins?

Frequently Asked Questions

Can You Clean The Air Intake Sensor?

Yes, you can clean the air intake sensor. It is important to clean the air intake sensor regularly. It will help increase the performance and longevity of the IAT sensor. A good practice would be to make cleaning a part of your regular maintenance for the vehicle.

What Does The IAT Sensor Control?

The IAT sensor does not control anything. Instead, it checks the air that the engine is intaking. Then, the IAT sensor tells the system about the density of the air. Depending on that, the PCM determines the supply of fuel to the engine. A proper ratio of air and fuel does the magic for the engine.

How Long Do IAT Sensors last?

Generally, an IAT Sensor can last around five years. However, its lifespan can be short since it’s a delicate component. Even a little glitch in the electric wiring can damage the whole IAT sensor. So, you cannot predict the exact longevity of your vehicle’s IAT sensor.

Parting Words

Do you still have any queries about the P1193 code in 6.7 Cummins? You can leave your comments below. I will be glad to know your opinion about the article. Also, do tell us if you could resolve the P1193 code by yourself.

This is it for today. Have a great day!