How To Troubleshoot & Fix p1494 Jeep DTC Code?

Most of the time, owners of the four-wheeled beasts enjoy their rides but don’t maintain them as needed. Thus, their favorite vehicle runs into issues, and several diagnostic trouble codes appear on the dash. P1494 is one such code.

Fortunately, dealing with the code is not a big deal. In no time, you’ll know how to troubleshoot and fix the P1494 Jeep code. Let’s go ahead without wasting time.

What Does P1494 Jeep Code Mean?

P1494 is a DTC code that can appear on the onboard computer of your Jeep. The code indicates ‘Leak Detection Pump Pressure Switch Condition.’ 

Simply put, this code indicates a problem with the engine’s evaporative emission control system, which stops harmful emissions from the engine from entering the atmosphere. 

The mentioned leak detection system checks for blockages and leaks in the EVAP system. As your vehicle goes through self-diagnostics, the powertrain module inspects the leak detection pump for mechanical and electrical defects. 

If no leaks are found, the vent valve is sealed, and the PCM employing the LDP pumps air into the system to increase the pressure. 

If a leak is detected, the pumping is continued by the LDP to replace the air that is leaking out. Here’s a breakdown of the p1494 code for better understanding-

  • P= OBD-II Powertrain trouble code for the engine
  • 1= A Manufacture specific number
  • 4= Auxiliary emissions control detected
  • 94= Specific fault index (In this case, it denotes EVAP leak detection pump pressure switch condition) 

P1494 Code: What Causes EVAP Leak Detection Pump Pressure Switch Fault On Jeep Grand Cherokee?

Several reasons are responsible for generating the code P1494 on your Jeep Grand Cherokee.

However, the most common reason is a faulty leak detection pump, and sometimes the code display is simply a technical misunderstanding. Anyway, the most common reasons include the following:

  • Open or shorted harness in the Leak Detection Pump (LDP)
  • A leak in the EVAP system, such as a cracked or split hose or a damaged fuel tank
  • A failed leak detection pump or pressure switch
  • A problem with the electrical connections to the leak detection pump or pressure switch

Read Also: How to troubleshoot & Fix P06dd Jeep Wrangler DTC Code? [Top 4 Fixes]

How To Troubleshoot & Fix p1494 Jeep Code?

To deal with the P1494 code, you need to troubleshoot and find the exact reason why the code has been stored. 

There is every possibility that the LDP system will be damaged or the Jeep EVAP system will run into issues. 

Before your loved four-wheeler may incur a massive loss, and so will you. To prevent that, it is important to troubleshoot as far as the symptoms are verified. Let’s see how to do that and save your precious Jeep from unnecessary damage. 

1: Scan the system for other DTC codes

To begin the diagnostic process, you need a scan tool to scan the system. To scan for other DTC codes, you need a code scanner. 

Don’t worry; these scanners are readily available at cheap prices in the market or online. 

You need to use the scanner to find out if your vehicle is displaying any other codes along P1494. 

Your first job is to get rid of all the related code, test drive the vehicle and rescane. 

Read Also: How to troubleshoot & Fix C121C Jeep DTC Code?

2: Inspect the LDP Switch

Your next task is to check the LDP switch and ensure it’s working properly. But how? 

If the switch closes when a vacuum is applied to the system and opens when the vacuum is released, it’s in a healthy state. If not, you need a replacement. 

The cost of a leak detection pump switch depends on the type, brand, and model. 

On average, it ranges from $30 to $100. It is best to check for the right switch in your local hardware store or online for a more specific result.

3: Check the Leak Detection Pump

Next, you need to diagnose the LDP pump to see if it’s functioning properly. The LDP is responsible for pumping air into the system after the PCM directs it to do so. 

You need to carry out a bench test on the LDP using a 21 inches vacuum, 12V running power, fused jumper leads, and finally, a grand sour from switched power. To learn the process, you can watch this youtube video-

If you have a damaged leak detection pump, it’ll naturally cost you a few hundred bucks to install a new one. 

The average cost of the parts will range from $200-$250, and almost $100 will be for labor. 

Read Also: How to Troubleshoot & Fix P0128 Jeep Wrangler DTC Code?

4: Inspect the vacuum hoses: 

If none of the above steps work for your specific problem, check all the vacuum hoses that connect the LDP switch to the engine. Inspect if there are any cracks or leaks in the hoses. and replace the damaged hoses. 

Fortunately, vacuum hoses are pretty substantial, although expensive compared to other parts of your engine or the LDP system. 

But the good side is investing in a standard hose will make it last for years. On average, the cost ranges from $190-$600. 

5: Check for a damaged fuel/gas cap

There is every possibility that the evil behind the ‘Leak Detection Pump Faulty Switch’ code generation is a damaged or loosely-fitted fuel cap. 

So, before you check other parts, you need to inspect the condition of the fuel cap first. 

Sometimes, simply securing or tightening a loose fuel cap can help you get rid of the code. But if that’s not the case, you will need to repair the fuel cap at once.

However, a tiny issue here is that a damaged or problematic fuel cap is not always visible to the bare eye. And hence, if tightening the cap doesn’t work, simply replace it. 

A new fuel cap can cost you very little, around $30 to $90 at most. And sometimes, you can simply get done with securing the cap. 

6: Inspect the canister vent valve:

Similar to the EVAP system leak code, the LDP faulty switch code may also be generated due to a faulty canister vent valve. If you’re unaware of how the canister vent valve works, here’s a breakdown

It simply controls the flow of air inside or outside the Evaporative Emission Control System, or, shortly, the EVAP system. 

When your vehicle is powered on, the vent valve is usually open and is only commanded to close to seal the EVAP system and prevent airflow into the charcoal canister. 

The LDP solenoid creates a barrier in the engine vacuum port and opens the connected atmospheric pressure port, employing the air filter of the EVAp system. In this case, the vent valve is opened, allowing the canister to check the atmospheric pressure. 

At times, you may have a clogged canister vent valve. You need to blow through its openings when the valve isn’t powered to check if it is working fine. 

If you cannot do so, it means the vent valve is sealed and working fine; the other way around, you need a new vent valve. 

The typical cost of a new vent valve is between $100 and $130. Again, you might end up spending at most $40–$60 on labor costs.

Read Also: How To Troubleshoot & Fix P1521 Jeep DTC Code?


By now we have covered many relevant aspects of the code P1494 on your jeep. Here are some frequently asked questions that you might want to know.

Can you drive a Jeep with p1494 Code?

Yes, you may still drive your jeep with a P1494 code running. However, there is a high possibility that your LDP is shortened or dead. So, if there’s a leak in the EVAP system and your LDP cannot recognize it, it can become a serious issue soon!

How Much Does It Cost to Fix Jeep p1494 Code?

If you’re lucky, you might spend only a few dollars to fix the P1494 code. However, with major issues, you will be spending a few hundred bucks at a minimum, and of course, there’s the labor cost too!

Where is the leak detection pump located?

Typically, you’ll find the leak detection pump behind the back wheel on the vehicle’s passenger side. The leak detection pump is used to pressurize the fuel system to check for leaks in the EVAP system. 


You might think the P1494 error isn’t that serious, but don’t discount the possibilities that your LDP system is down. There are other possibilities as well. To deal with the issue, find the root cause for which the code is present. Once it’s fixed, you can enjoy smooth rides again!

Read Also: P0455 Jeep Wrangler Code: EVAP System Large Leak Detected

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