These top 5 Toyota Highlander problems cover the 1st generation model made between 2001 and 2007. They are not the only problems that you’ll experience while using the Highlander. They are just but a few of those that we have found common among most owners. In today’s post, we highlight the symptoms you’re likely to get when facing these issues and their possible repairs. Let’s take a look.
Video: Top 5 Toyota Highlander Problems
Diagnose and Fix Common 1st Generation Toyota Highlander Problems (2001 to 2007)
1. VVT Oil Feed Hose
Symptoms of a Bad VVT Oil Feed Hose
The 1st Generation Toyota Highlander has the hose either at the back of the head or at the front just behind the timing cover. When it bursts, you’ll have a severe oil leak that will require you to shut off the engine to avoid catastrophic failure.
Causes of a Bad VVT Oil Feed Hose
The VVT oil feed hose found in the Toyota Highlander is not high spec enough. As a result, it tends to wear out due to corrosive contaminants that are found inside old and hot oil. Some engines have the oil feed hose located just underneath them.
How to Fix a Bad VVT Oil Feed Hose
A common fix for this is to replace the VVT oil feed hose with a new solid line that is chemical resistant and lasts longer.
2. Check Engine Light After Air Filter Maintenance
Symptoms of CEL After Replacing the Air Filter
Another common Toyota Highlander problem that a lot of owners encounter is seeing a check engine light pop up on the dash just after replacing the air filter.
Causes of CEL After Replacing the Air Filter
This is mainly caused by hoses that may have been knocked off while doing some maintenance.
If you take a look at your air filter box, it has small hoses that connect to it. These are pretty easy to knock off. If you drive the car while they are not well-connected, you’ll get a check engine light that generates a related code.
How to Fix a Check Engine Light After Replacing the Air Filter
The best fix for this would be to check the hoses to see that they are all in the right position. This should also help clear the code.
3. Failed Oxygen (O2) Sensors
Symptoms of Failed Oxygen (O2) Sensors
Our third Toyota Highlander problem concerns a drivability issue that’s caused by a bad oxygen (O2) sensor that usually manifests as a rough running engine.
Causes of Failed Oxygen (O2) Sensors
The Highlander has one O2 sensor located in front of the engine and another at the back. You’re not going to have much of an issue if the back O2 sensor goes bad. This is because the front sensor is the one that controls the air-fuel ratio.
The one at the back only monitors the catalytic converter. This means that if you notice that your engine is running rough or get a code for the O2 sensor, the problem is most likely with the one located at the front.
How to Fix Failed Oxygen (O2) Sensors
A simple replacement should fix the problem.
4. Ignition Coil Failure
Symptoms of Ignition Coil Failure
The V6 engine in the Toyota Highlander has three ignition coils on the front side and three at the back just underneath the intake. When these fail, you’ll get a check engine light and have an engine that’s running rough. The check engine light may even be flashing.
How to Fix Ignition Coil Failure
The best solution for the problem is to replace all the ignition coils at the same time. It’s also a good idea to replace the spark plugs as well. You’ll need to remove the intake to access those located at the back. Remember to replace the gasket while doing the repair.
5. Center Airbag Sensor Assembly
Symptoms of a Bad Center Airbag Sensor Assembly
Our last Toyota Highlander problem on this list concerns the center airbag sensor assembly. The sensor sends information that helps to activate the airbag or diagnose a system malfunction. It’s located underneath the center console and requires you to remove a lot of interior parts to gain access to it.
One of the symptoms that you’re likely to notice when the assembly goes bad is seeing the airbag light come on with a code for the sensor.
How to Fix a Bad Center Airbag Sensor Assembly
You’ll need to replace the sensor to clear the code and get rid of the light on the dash. If this does not fix the problem, you may have to take the car to the dealer and have it reprogrammed.
First Generation Toyota Highlander Model Years
- 2001 Toyota Highlander
- 2002 Toyota Highlander
- 2003 Toyota Highlander
- 2004 Toyota Highlander
- 2005 Toyota Highlander
- 2006 Toyota Highlander
- 2007 Toyota Highlander
Related Content
- Can an O2 Sensor Cause a Misfire?
- How to Diagnose an Engine Misfire
- Signs of a Failing or Bad Ignition Coil
- How to Test If an Ignition Coil Is Bad
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