2002 Chevrolet Cavalier 2.2, Engine Light on with a P0440 Code Stored

This 2002 Chevrolet Cavalier 2.2 came into the shop with a DTC P0440 Evap Emissions System Fault.  The first thing we did was to give a visual inspection of the EVAP system.

We did not see any obvious problems, such as, broken or disconnected hoses, unplugged components (i.e. purge or vent solenoid), broken wires, or loose/missing gas cap.

Many people, when presented with this code, will automatically replace the gas cap.  While these caps do need replacing from time to time for maintenance issues, this may not solve the problem.  In this case, the gas cap was not the issue.

We then decided to use our diagnostic tool and, using its bi-directional command capability, commanded the purge and vent solenoids on and off.  When we did, we heard (and could feel) each one turning on and off as we commanded it.  We did this several times to ensure there was not an intermittent problem with sticking in the solenoid.

Next, we connected our smoke machine, which we use to check for EVAP leaks.  Again, using the diagnostic tool, we commanded the vent solenoid on (which closes the valve . . . this valve is normally off and thus open, to do the test it must be "On", meaning the vent is closed, so as to allow the system to hold the smoke in), and tested the system with smoke.

The picture below shows the evidence.  It is a bit hard to see, so we have drawn an arrow to point to the evidence.  What we saw was smoke boiling out of the vent solenoid, even though we were commanding it "On", thus closing the vent.  Therefore, with the vent "On" no smoke should have been escaping.

With this evidence, we removed the vent solenoid.  What we found is that someone had tie-strapped the diaphragm.  More than likely, a previous owner (our customer said they had not done this) knew about the problem and tried to rig it to work.  Not a good idea.  The solenoid was actually leaking from around its diaphragm, so a new one was in order.  A picture of the old one, tie-strap still on is below.

The next picture shows the new vent solenoid in place.

  
Just FYI, there is a short wiring harness (see below) connected to the vent solenoid.  These are notorious for fraying and breaking, due to rear end movement.  Like the gas cap above, this was not the cause of this failure.  Silver bullet fixes usually end up costing a customer far more money than simply taking it in to a professional to have it properly diagnosed and repaired.

Here is the short wiring harness (I am pointing to it in the picture).

After completing the repair, we cleared the codes and data associated with it.  We then ran a EVAP system test with our smoke machine.  The test passed.  A picture of that is below.  You will notice the green lit LED indicating the test completed and passed.

There are many variables when it comes to diagnosing and repairing an EVAP system.  A basic understanding of how the EVAP system works on that particular make and model is essential.  A visual inspection is always the first place to start.

Don't jump at silver bullet fixes.  You may get lucky and it may be your problem and repair your vehicle.  Then again, you may spend quite a bit of money chasing several silver bullets and in the end be left with the original problem.

When in doubt, find a professional you can trust and take it to him/her and let them do the proper diagnostics and repairs.  It may end up saving you far more money in the long run.

I know the economy has been rough and times are tough.  But, throwing parts at a problem can compound that problem quickly.

1998 Chevrolet S10 2.2, Brake Lights Not Working

This vehicle came into the shop with a customer concern of no working brake lights.  The vehicle had been taken to another repair shop a few weeks ago and the customer was told it would cost several hundred dollars to repair the problem.

I confirmed that all three brake lights were inoperative.  This model has the customary two brake lights on the rear and a brake light called the Center High Mount Stop Light, or CHMSL for short.  All three brake lights were inoperative. (After doing some further investigation after I repaired the truck, I found the CHMSL bulbs were blown.)

This led me to a quick look at a wiring diagram, which led me to take a look at the Underhood Fuse Panel.

When I removed the cover something caught my eye, even before I could check any fuses.  I noticed something was missing.  Where I am pointing you will notice four empty cavities.  This is where the CHMSL Relay is suppose to be . . .  but it's not!  The relay would look like the relay above my finger (the grey rectangle).

I happened to have one in the shop.  I plugged it in.  Below I am pointing to the now present CHMSL Relay.

Sure enough, with a quick test of the brake pedal . . . presto!  the brake lights were working.

This is a quick post just to remind us not to overlook the small things.  Before pulling out the PowerProbe or Test light or whatever else, be sure to give a visual inspection of the components.  As this job reminds us, first make sure they are where they are suppose to be; and second, make sure they are in good/working condition.

Sometimes the easy, simple solution is the right one.

2002 Jeep Liberty Limited 3.7, Ignition Key Issue

This Jeep came into the shop with a customer concern dealing with the ignition key.  The key would turn too far in the cylinder and would not crank or start the vehicle.  Also, when the key was turned back and taken out, the dash lights were staying on and causing the battery to drain.

***Another symptom of this failed part is when the key will not turn all the way to the off position to be removed.  Customers will complain that their key is stuck and they can't remove it.***

The battery cable was disconnected.  I started by removing the upper and lower steering covers.  You need a 20 Torx Head Bit to remove the two screws.  One is to the left of the steering wheel and the other is to the right.

 

 

I then dropped the lever for the tilt steering down so it was out of the way.

 



I then removed the upper and lower covers.  This allowed me to have better access to the key tumbler/lock cylinder. 

The black plastic piece around the outer part of the lock cylinder is the halo ring.  There are two plastic tabs that hold it in place.  I couldn't take a picture while removing it.  But in the photo below you can see the two tabs.  Just be careful not to overstress them and break them.

 

 

Next, on the bottom of the cylinder is a locking tang, with the key turned to the on position, depress the tang.  I used a pick, but a small screwdriver or the like would work fine too.

 

 

 

Once I depressed the tang, I pulled the cylinder from the housing.

 





Next, I had to remove the lock cylinder housing retaining screws.  The two screws holding this on are T10 Anti-Theft/Securtiy Torx Bits.  (These are a bit different from a normal torx bit headed screw.  The difference is the Anti-Theft torx bits have a hole in the center of them.)

I then removed the ignition switch (the electrical part) from the steering colum.  Once again, the screw is a T10 Anti-Theft/Security Torx Bit. 

 

 

I disconnected the electrical connector at the ignition switch (it has a red saftey tab that must be pushed back before the tab will release.)  I removed the ignition switch (the black piece in my hand) and the ignition actuator at the same time.  The ignition actuator is the white plastic piece attached to the switch.

Below is another photo of the two parts still attached.

I then removed the actuator from the switch.  I did this by gently pulling the actuator from the switch.  Once it was removed the problem was found.  The aluminum had broken off inside of the switch, allowing the key tumbler to turn freely.  You can clearly see the two aluminum pieces.

Here is the new ignition actuator. 

To reinstall, I simply fitted the actuator and the ignition switch together (if you are doing this be careful, the actuator can come apart.  The best way I have found to prevent this is to hold a finger at the back of the actuator as you push it into the switch; thus, keeping everything together.  If it does come apart on you, don't panic, it is easy to reassemble.)

I then reinstalled all the parts in the reverse order and the key turned as it should in the cylinder and the vehicle started right up.  I charged the battery because of the previous drain condition.  All is well!