If you are a Jeep lover and off-road adventurer, you want the thrill of conquering rugged terrain and challenging landscapes in your trusty Jeep. You rely on the axle lock system in your Jeep when the going gets tough. It can be the difference between overcoming the obstacles easily and finding yourself stuck in the muck.
You take it for granted until trouble strikes. Typically, it appears as a blinking light. Then the light stays, and you get an error message – Service Axle Locker System. You won’t be able to engage/disengage the locking system at all sometimes. Even if you have not done any off-roading at all, you may run into this issue. Because it’s root cause is faulty system design. 2018 or newer Jeep Wrangler Rubicon and 2020 or newer Jeep Gladiator suffer mostly from this issue, especially the 2019 Rubicon, 2018 and 2021 Jeep Wrangler.
The root cause behind the Service Axle Locker System error is the faulty locker position sensor. But sometimes, problems with the wiring harness, connector, connector cable, electronic control module, software updates, etc., can trigger the issue.
In this article, I’ll explain what the axle locker system is, explore the common causes of the Service Axle Locker System issue, and leave you with a comprehensive understanding of what you need to do to find out the issue if you face this problem.
So, let’s dive in and discover how to ensure you can always depend on your Jeep’s axle lock system on your off-road journeys. But first, what does an axle locker do?
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What Is an Axle Locker?
You must maintain traction while driving your Jeep off-road, tackling rough trails and muddy paths to keep moving forward. That’s where the axle lock system comes into play. It locks both wheels on the same axle together, making them work as a team.
Usually, your wheels can turn at different speeds when you’re steering. But the axle lock steps in when you’re off-roading and encounter tricky spots where one wheel starts slipping because it has less grip (like in mud).
When you engage the axle lock, it forces both wheels on that axle to spin at the same rate, no matter what. So, the wheel with good traction helps out the struggling one. This power-sharing improves your Jeep’s ability to keep moving forward, even in challenging conditions.
However, you should only use the axle lock when off-roading or dealing with slippery surfaces. On regular roads, it’s not needed and can cause problems during turns. So, remember to turn it off when you’re back on the streets.
But sometimes you see blinking lights on your dash. If you have locker blinking lights or the Service Axle Locker System error, you have a problem with your axle locker system.
Let’s understand why this issue is so common in Jeeps.
Service Axle Locker System: What Are the Causes?
The Service Axle Locker System error message is more common on modified/geared vehicles. But you may see it on a low-mile stock Jeep as well. Various issues within the axle lock system can trigger it in a Jeep. Here are some common causes:
1. Sensor Fills With Fluid and Malfunctions
This is a common problem in JL and JT Rubicon with factory shockers. Modern Jeeps have sensors that monitor the status of the axle locker system. This lock position sensor tells the computer where the lock or position is, whether locked or unlocked. When this sensor malfunctions or provides incorrect data, the system may not engage or disengage correctly, leading to error messages.
Over time, differential fluid slowly leaks into the lock position sensor. This fluid has metallic flakes in it. These flakes come from the bearing and gears. The fluid combined with the metallic flakes causes the locker sensor to short out. The malfunctioning sensor then causes haywire on and off until it fails completely.
This causes the locker light to blink, and the Service Axle Locker System error comes on at a certain point.
Your dealership may say that you have a failure in the locker actuator. They may also say that you have a faulty rear actuator, a short circuit in the rear axle at the locker actuator solenoid, or that your whole axle is malfunctioning.
All of these things mean the exact same thing. Your lock position sensor is not working, causing problems with the axle. Hence, you can’t engage and disengage the axle lock now and see the Service Axle Locker System error.
2. Fluid Leaks Into the Wiring Harness
Sometimes, the wiring harness end gets oil and causes ground faults. Oil can seep from the plug located above the transmission. This leads to oil leaks into the wiring harness. The wiring harness and the area around the plug may have oil patches.
The issue comes from the O-rings within the plug situated above the gearbox. When these rings fail, they allow oil to escape. It leads to electrical malfunctions due to poor connections caused by ground faults.
3. Problems With Internal Wiring
If your Jeep has problems with the electrical components, such as wiring connectors, they can trigger the Service Axle Locker System error message. These issues may include damaged wires, loose connections, and bad ground, which disrupt the proper functioning of your axle lock system.
- The wire can break near the axle locker sensor. It can break very close to the connector to the casing.
- There can be coupling issues. Sometimes, the internal wiring is not appropriately sheathed. Hence, they rub against each other and get chafed.
- The wire in the harness close to the axle can get corroded.
- Another problem is that there can be bad ground somewhere.
These issues cause the blinking locker light to come on and the display’s Service Axle Locker System error.
4. Loose/Broken Connector
Another common issue lies in the connector. It’s a simple issue that people tend to miss a lot. The locker plug connector is very sensitive. Several types of problems can cause faulty connections.
Loose Pins Due to Wear and Tear
Over time, the pins within your locker plug connector may become loose or damaged. Your connector or connector cable can become loose or broken. This can occur due to the natural wear and tear associated with the off-roading, constant engagement, and disengagement of the lockers. Especially when you overstretch your Jeep during off-roading.
Abrasion and Moisture
Abrasion from the terrain encountered during off-roading can contribute to connector issues. Additionally, moisture infiltration, which is not uncommon when driving through wet or muddy terrain, can worsen problems within the connector.
Sometimes, your locker plug connector may suffer from poor initial production quality. If the connector was manufactured with flaws, it may lead to premature failure, causing the locker light to blink.
5. Low Fluid Levels
Jeep sometimes ships cars from manufacturing plants with very little differential fluids. Also, some models may use a limited-slip or locking differential that requires specific fluids. Your axle lock system’s ability to function properly may be hampered if these fluids are low or contaminated.
6. Software or Control Module Issues
In modern Jeeps, an electronic control module controls the axle lock system. Software glitches, programming errors, or issues with the control module can cause the system to malfunction and trigger error messages.
Many people complain that this issue is triggered by the PCM software update that is done as part of a recall.
7. Overuse or Abusive Driving
Frequent use of the axle lock system in extreme off-road conditions without proper maintenance or allowing it to remain engaged on regular roads can accelerate wear and potentially cause errors.
Some wires go to the electronic lockers. When you stretch or overstretch your Jeep while off-roading, those lines can rip out or short out, causing a Service Axle Locker System error.
8. Blown Fuse
If you are seeing the error message, check the fuse box. You may discover that the fuse for the lockers is blown. Usually, the fuse blows because there is an inherent problem with the locking system.
9. Mechanical Problems
Physical components of the axle lock system, such as actuators, solenoids, or the locking mechanism itself, can wear out over time or become damaged due to off-road use. These mechanical issues can result in difficulty engaging or disengaging the axle lock system.
You need to thoroughly inspect the system, including its electrical components, sensors, and mechanical parts, to resolve the Service Axle Lock System error message. Depending on the specific cause, the solution may involve repairing or replacing damaged components like sensors, connectors, or the wiring harness, performing maintenance tasks, recalibrating sensors, or addressing software-related issues.
Can You Drive With the Locker Light On?
If you see the locker light on or the error message on the dashboard, you can keep driving because you only need it when you are on the trail. But you should check out the problem as soon as you can. Because you never know what the real issue is. It can cause situations like engaging on a highway, and that would be dangerous.
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The axle lock system in your Jeep stands as a trusted ally, ready to tackle the toughest challenges. Yet, it can encounter issues that warrant attention and care.
Throughout this article, I’ve explored the critical steps of servicing your Jeep’s axle lock system. You’ve learned what this system entails and the common causes of Service Axle Locker System error messages. These causes range from sensor malfunctions and fluid leaks to wiring concerns and mechanical glitches.
Thankfully, there are solutions at hand. Whether it’s diagnosing and repairing sensor issues, addressing fluid leaks, recalibrating components, or performing comprehensive maintenance. You have several options to ensure your axle lock system functions optimally.
So, gear up, stay informed, and let your Jeep’s axle lock system unlock the full potential of your off-road journeys.