Featured Content

To help with your repair solutions, here's a collection of TechSmart articles. 

Don't Get Burned by HID Lighting

- by Ryan Kooiman

Remember when a customer could stop by a shop and a technician could “quick a minute” install a new headlight?  Those days are distant memories for many technicians. With new body designs and technologies such as High Intensity Discharge (HID) lighting, a “simple burned out bulb” may now require significant diagnosis and removal of the front bumper cover to gain access—all of which could lead to a hefty repair bill.

I recently heard a story that underscores why you shouldn’t underestimate the complexity of HID bulbs. Here’s the short of it: a salesperson from a used car department brought a newly purchased Ford Flex with a burned out headlight to one of the dealer technicians. The salesperson thought the vehicle needed a quick bulb replacement. Instead, it required a complete replacement of the headlight assembly (it was cracked and waterlogged), a new HID ballast, and a new HID bulb!

Unlike older halogen headlights, which use a filament to produce light, HID bulbs use electricity arcing between two electrodes to produce light. As a result, the HID system requires more than the 12 volts typically required for a vehicle to run. To provide the higher voltage needed to produce the brighter light, the system needs a ballast to a) start the light when it’s first turned on and b) adjust it to a lower voltage (80-90) to maintain the illumination.  Due to the high voltage and extreme temperature of the bulbs, it’s important to use extreme caution when working with or testing them.

Given the potential complexity of modern HID repairs, it’s as important as ever to diagnose the jobs properly, quote all the required parts, and install quality parts that will perform as well as or better than the originals.

Kooiman 3 Ryan Kooiman is the Director of Training at Standard Motor Products. In addition to leading SMP's award-winning PTS training program, he is the face of SMP's 'Installation Spotlight' videos on YouTube. He has ASE Master L1, L2, and L3 Certifications, and has had articles published in over 30 periodicals.

6 Tips to Remember When Repairing HID Lighting Systems

To help you with your HID lighting system repairs, we asked the ASE-certified technicians from our award-winning training department for some tips on HID lighting system repairs. Here's what they recommend:

1. If the headlight assembly shows any sign of damage (water or dirt intrusion), make sure the entire assembly is replaced prior to replacing the ballast.

2. When servicing an HID system, make sure the Headlight Level Sensors are working properly. They are essential to proper performance of an HID lighting system.

3. If the vehicle has been in a collision or the ballast is burned out, ensure that proper voltages and grounds are present at the new ballast. Low voltage or a weak ground will damage the new unit.

4. Use caution not to touch the HID bulb. Due to the high operating temperature of the bulb, oil from your fingers can cause damage. If you’ve touched it, use rubbing alcohol to remove the oil from the bulb

5. In many cases, if the bulb is burned out, the ballast may be damaged, too.

6. Proper input and output testing should be performed prior to quoting the job to the customer.  

Read & Repair: Throttle Position Sensors

- by Ryan Kooiman

Our “Read & Repair” series gives you background information about a particular part as well as tips to help with the job. Today’s topic is throttle position sensors. Let's get started.

How Do Throttle Position Sensors (TPS) Work?

TPS SchematicMost throttle position sensors (TPS) are 3 wire potentiometers. They have a power supply (typically 5 volts), a ground, and a signal return wire. Inside the TPS is a mechanical arm that’s attached to the shaft that holds the throttle blade. As the throttle moves, the arm makes contact at various points on a resistor strip. The correlating voltage is then sent through the signal line to the Powertrain Control Module. Newer TPS use a non-contact method and Hall effect-type sensors.

It’s important to note that proper adjustment of the TPS is critical. A misadjusted TPS will result in poor idle, stalling, lack of power, and improper transmission shifting, just to name a few issues.

The Trouble with Honda and Acura Throttle Position Sensors

Traditionally, throttle position sensor replacements are straightforward jobs: you remove the two mounting screws, install and adjust the new sensor, tighten down the screws, and the job is done. Some manufacturers such as Honda and Acura, however, rivet the throttle position sensor to the throttle body. As a result, when the TPS fails, you need to purchase a complete throttle body assembly.  

So How Do You Remove Faulty TPS on Those Hondas and Acuras?

1. Drill out the rivets. Note: You may need to remove the throttle body for access. Also, don’t use an oversized bit. Otherwise, you risk making the hole bigger than it originally was.

2. Once you remove the old unit, install the new throttle position sensor and attach it to the throttle body. TechSmart’s Throttle Position Sensor Repair Kits come complete with a gasket and mounting hardware, including screws that have hardened threads that cut into the aluminum throttle body.

3. Refer to service information to find the proper specs for the vehicle. Generally speaking, most throttle position sensors will read approximately 0.5 volt at closed throttle and 4.5 volts at wide open throttle.  You can verify the reading by using a scan tool or a voltmeter.  

Kooiman 3 Ryan Kooiman is the Director of Training at Standard Motor Products. In addition to leading SMP's award-winning PTS training program, he is the face of SMP's 'Installation Spotlight' videos on YouTube. He has ASE Master L1, L2, and L3 Certifications, and has had articles published in over 30 periodicals.

Throughout the years of internal-combustion gasoline engines, the main responsibility of a throttle body has been to contain the throttle plate (or blade), which is a device that controls the amount of air allowed to enter the engine. 

The same holds true today. In essence, an internal combustion engine is an air pump. The more air that enters and exits the engine, the more power/torque is generated in the engine.  The throttle body is the primary gatekeeper of how much air is allowed to enter the engine.  

Traditionally, the throttle plate has been connected to the accelerator pedal (or gas pedal) via a cable.  If the driver wants to go faster, they press the pedal, which in turn pulls the cable and opens the throttle plate to allow more air to enter the engine. Likewise, if the vehicle is equipped with cruise control, it has another cable connected to the throttle plate and the cruise control servo.   

In addition to a throttle plate, the throttle body contains an Idle Air Control (IAC) valve, which allows air to bypass the throttle plate and control the vehicle’s idle speed.  When open, the IAC allows more air to enter the engine, which raises the idle. When closed, it decreases airflow and lowers the idle speed. Monitoring all of the throttle movement is a Throttle Position Sensor (TPS).  

Due to new technologies (such as hybrid vehicles and electronically controlled diesels) and the need for reduced emissions and increased efficiencies, manufacturers started using electronic throttle controls, or “drive-by-wire” systems. The system takes the direct throttle control away from the driver and gives it to the Powertrain Control Module (PCM).  

Electronic Throttle Control 1 

A Simpler Process 

The process is simpler with Electronic Throttle Control. To make a request, the driver simply presses on the accelerator pedal (APP), which is essentially a spring with several built-in position sensors. The PCM then analyzes inputs from various systems and sensors on the vehicle (transmission, traction control, engine temp, engine load, etc.) and sends a command to an electric motor in the throttle body, placing it at the desired position. 

Throttle Body Cutaway 1

The position is determined by one of several throttle position sensors (TPS) built in to the unit.  The TPS reports the position to the PCM, which then adjusts the system accordingly.

Benefits of ETC systems include powertrain protection, better control, driver comfort, and component reduction, as there is no longer a need for a throttle cable, cruise control servo, or IAC valve—the PCM and the throttle body motor can handle all of those functions now.  

New Service Opportunities 

With improvements and changes come new service opportunities, because the new systems have their own problems that can be troublesome for drivers and frustrating for technicians. Common concerns from drivers include illuminated CELs and vehicles stuck in limp mode. Those faults may occur for only a few milliseconds but the symptoms can last for an entire drive cycle, making them difficult for a technician to pinpoint. For instance, does the fault code indicate a problem with a TPS sensor or the engine wiring harness? Is the fault due to an electric motor or a wiring problem somewhere? Is there a software update available for the vehicle? The technician must answer all of those questions for a proper diagnosis.

Once the technician determines the need to replace the throttle body, they must use caution when installing the new one. For example, they must install the new gaskets or seals to prevent vacuum leaks, and torque the nuts and bolts to ensure a tight fit. Most important, the technician needs to follow the manufacturer’s instructions regarding idle relearn. 

Not All Relearn Procedures Are Alike 

Many manufacturers have a straightforward procedure that involves clearing the vehicle’s memory (previous idle conditions and fault codes) and then starting the vehicle and allowing it to idle for the following durations:

  • Two minutes in park with the A/C off
  • Two minutes in park with the A/C on
  • Two minutes in gear with the A/C off and a foot on the brake
  • Two minutes in gear with the A/C on and a foot on the brake

The process should be followed by a test drive (possibly including several closed throttle decelerations) to verify that the vehicle is repaired properly and doesn’t stall at idle.

On the other hand, some manufacturers have a more involved process, particularly Nissans from the late ‘90s and early ‘00s. The process seemingly requires the technician to do the hokey pokey, making them jump up and down on their left foot, hold their breath, and rub their left hand on their head. But if the complicated process isn’t followed with 100% accuracy, the vehicle will not idle properly and/or turn on the CEL. 

The Takeaway 

Regardless of which vehicle is receiving the new throttle body, it is very important for the technician to look up the proper procedure to do the idle relearn after the job. 

Kooiman 3 Ryan Kooiman is the Director of Training at Standard Motor Products. In addition to leading SMP's award-winning PTS training program, he is the face of SMP's 'Installation Spotlight' videos on YouTube. He has ASE Master L1, L2, and L3 Certifications, and has had articles published in over 30 periodicals.

Read & Repair: DISA Valves

Our “Read & Repair” series gives you background information about a particular part as well as tips to help with the job. Today’s topic is DISA valves.

What is a DISA Valve?

It isn’t something on your diesel, nor is it a component for your sink!  It’s a component used on various BMW engine platforms from 2001-2012 to control the length of the intake manifold runner.  


What Does DISA Mean?

DISA stands for Differentiated Intake System Actuator, or if you’re up to date on your German, you may call it “Differenzierte Sauganlage”.  If you’re familiar with domestic vehicle operations, you may know it as Intake Manifold Runner Control. Ford has used it in many of their popular V-6 and V-8 engines for years. GM and Chrysler also have their own versions. The DISA system is BMW’s version of IMRC.


How Does the DISA System Work?

TEC Variable Intake Runners

When an engine’s intake valve is open, atmospheric pressure forces air into the low-pressure area inside the cylinder. When the intake valve closes, the air in the intake runner that’s moving rapidly toward the cylinder slams to a stop and stacks up on itself, forming an area of high pressure. This high-pressure wave makes its way up the intake runner away from the cylinder. When it reaches the end of the intake runner, the pressure wave bounces back down the intake runner.

If the intake runner is just the right length, the pressure wave will arrive back at the intake valve just as it opens for the next cycle. The extra pressure helps force more air-fuel mix into the cylinder. The problem with this technique is that it only provides a benefit in a relatively narrow rpm range.  

To improve power and efficiency, it is also beneficial to have the intake air moving as fast as possible into the cylinders. Doing so will increase turbulence and better mix the fuel with the air. One way to increase air velocity is to use a smaller diameter intake runner. Think about it. The volume of air entering the cylinder each cycle is roughly the same. If that volume of air runs through a smaller diameter pipe, it will have to move faster.

There’s a downside to using a smaller diameter intake runner, though. At high engine speeds, when a lot of air is moving through the pipes, the restriction from the smaller diameter may inhibit airflow. For large airflows at higher speeds, it is better to have large diameter pipes. 

For the best of both worlds, manufacturers such as BMW now use dual intake runners for each cylinder, one with a small diameter and one with a large diameter, or varied lengths. They use a butterfly valve to close off the large diameter runner at lower engine speeds when the narrow runner can help performance. At higher engine speeds, the butterfly valve opens to reduce the intake restriction, increasing the top-end power output. At the end of the day, what you need to know about DISA systems is that they use long intake passages at low rpm and short passages at high rpm.

"At the end of the day, what you need to know about DISA systems is that they use long intake passages at low rpm and short passages at high rpm."

What’s a Common Cause of Failure?

When a BMW DISA valve breaks, one of the first concerns a customer may have is a knocking noise coming from the engine compartment. The noise is the sound of the DISA valve flap freely spinning on the broken plastic shaft.


What Causes the DISA Valve to Break?

Over time, carbon builds up in the intake manifold. When it builds up on the DISA valve, it can prohibit the flap from closing and opening fully, causing either the plastic flap or the plastic shaft to break.   

In some cases, the customer may have concerns of rough idle, lack of power, illuminated Check Engine Light, or vehicle hesitation.  All of those concerns are the result of the flap either moving back-and-forth or being stuck in the incorrect position. In either case, the DISA Valve is broken and needs to be fixed. 


What’s the Best Solution for a Broken DISA Valve?

In the OE world, the only option is to replace the entire DISA unit. Now, if the housing is damaged and the vacuum is leaking, a full replacement is required. But for most DISA-related problems, all that’s needed is a repair kit such as TechSmart’s DISA Valve Repair Kits. These kits come complete with everything a technician needs to repair only the unit rather than replace the entire thing, which can save customers a lot of money. 


Two Tips to Remember for DISA Valve Repairs

Once the new components are installed on the DISA Valve, use caution to install it, and make sure the vacuum lines and electrical connector are connected. If any trouble codes were stored or any drivability concerns are noticed, the stored memory should be cleared before verifying that the repair is complete and the problem is corrected.


Kooiman 3

Ryan Kooiman is the Director of Training at Standard Motor Products. In addition to leading SMP's award-winning PTS training program, he is the face of SMP's 'Installation Spotlight' videos on YouTube. He has ASE Master L1, L2, and L3 Certifications, and has had articles published in over 30 periodicals.

In honor of Earth Day on April 22, this month I’m going to discuss technology changes in the automobile, and show how they’ve become more environmentally friendly. Let's get started.

Most of you are familiar with electric vehicles, which have no tailpipe emissions, but there are also newer technologies on the scene. One is Partial Zero Emissions Vehicles (PZEV), which don’t emit evaporative emissions from the fuel system and have tailpipe emissions that meet the qualifications of a Super Ultra Low Emissions Vehicle (SULEV). Other technologies include Advanced Technology PZEV (think natural gas Honda Civic GX) and Transitional ZEV (think plug-in hybrid). You could almost say these cars clean the air they use, because they inhale dirty air and emit clean air!

The vehicles that most of us drive each day may not have a fancy acronym, but they are nonetheless doing a better job of being Earth-friendly than their counterparts were 30-40 years ago. Exhaust systems and catalytic converters are one huge reason for this, and I could go on for 15 pages about how they work to clean things up but I’d put you to sleep by the end of the first page! Instead, I’ll highlight other technologies such as Electronic Throttle Control, Exhaust Gas Recirculation, Evaporative Emissions, Variable Valve Timing, and enhanced fuel and ignition control.

Electronic Throttle Control

Pumping Losses

You may be asking yourself how electronic throttle control affects vehicle emissions. Well, with electronic throttle control, the vehicle can use a different fueling strategy and control the engine speed more precisely during cold starts to “light the catalytic converter” and get it working within seconds. The bigger benefit is the reduction of pumping losses created when the piston moves downward on the intake stroke and encounters a restriction in the airflow, which creates a vacuum and steals power from the crankshaft. In most gasoline engines, the restriction is the throttle plate. With electronic throttle control, the Powertrain Control Module can control the engine via fueling, ignition timing, and valve timing (if equipped) and open the throttle plate to allow the engine to breathe more freely, thus eliminating pumping losses.

Electronic EGR System


Exhaust Gas Recirculation (EGR) has been around for many years but manufacturers continue to make it more efficient and precise. EGR recycles some of the burnt exhaust gases back into the intake passage under predetermined operating conditions. The exhaust gas is inert, so it won’t burn again. Mixing the inert gas into the combustion chamber lessens the combustion (fire), which results in less heat and reduces the harmful greenhouse gas NOx. The system pictured above is the Electronic EGR system used by Ford. In the system, the EGR valve is an electronically controlled stepper motor with 52 varied positions of flow. The setup doesn’t have a feedback system, though some manufacturers like GM do include position sensors. The MAP sensor upstream from the valve monitors the EEGR system.

Tip: Need a transducer for a Chrysler with an EGR fault? TechSmart EGR Transducers allow you to replace only the faulty component instead of the complete assembly (including the valve that is still working fine).

EVAP System


The EVAP system captures gasoline vapors that would otherwise escape the fuel tank and enter the atmosphere, where the vapors react with air and sunlight to create smog.

For some background info, whenever fuel is in the tank, it is evaporating. In the past—especially in return-type fuel systems where unused fuel from the warm fuel rail returns to the cooler fuel tank and increases vaporization—the fuel was released into the atmosphere. Early EVAP systems were designed to capture the vapors. Newer systems have added Onboard Re-fuelling Vapor Recovery (ORVR), which captures the vapors released when a tank is refilled.

In the early 70’s, California made a push to reduce smog by requiring all cars sold in the state to be equipped with EVAP systems. The decision led to a variety of EVAP systems being introduced on vehicles across the country. Early systems had a purge valve, which allowed fumes captured in the charcoal canister to be drawn into the engine where they were burned. With the introduction of OBDII testing in 1996, the vehicle had to perform a self-test to see if the system was sealed and working properly. In 2000, the rules were changed with “enhanced” systems, where the vehicle had to monitor canister purge flow and detect leaks .020” and larger. Today’s regulations require the vehicle to detect leaks as small as 0.010”!

Variable Valve Timing


Variable Valve Timing (VVT) or Variable Cam Timing (VCT) is common on most newer engines. It’s responsible for increased performance and fuel economy on many engines, and for the elimination of many EGR valves.

Most systems are lube oil-activated, and they use a control solenoid as well as the camshaft sensor, crankshaft sensor, and PCM for control. Newer systems operate off rotational torque from the engine.

With a fixed camshaft, engineers have to balance between idle quality and performance on one side and low emission and fuel economy on the other. As a result, none of these goals are achieved completely. Variable valve timing allows the engine to obtain a smooth idle while achieving the rest of the goals. Modern VVT systems combined with technologies like electronic throttle control and direct fuel injection allow smaller engines to produce high horsepower and torque at lower RPM.


For increased performance, the exhaust cam is retarded a small amount to promote engine breathing. Higher engine speeds mean shorter valve open times and higher air velocity. The increased velocity pushes more exhaust out of the cylinder.  The retarded exhaust valve timing increases Volumetric Efficiency. The exhaust valve is still open when the intake opens. Outgoing exhaust pulse creates a low-pressure zone behind the valve, which increases the pressure differential between the intake port and the combustion chamber. The result is better cylinder filling. Remember, this can’t be done at idle due to low air speeds.

EGR Effect

To provide an EGR function, the exhaust cam is fully retarded, which adds lots of overlap. As a result, the exhaust gas remains trapped in the cylinder. This ability allows a reduction in hardware and service issues from carbon. Opening the exhaust valve later retains more exhaust pressure in the cylinder, causing pushback to the intake charge and exhaust gas retention.

Intake Advanced

On some systems, the intake camshaft is advanced at part throttle and WOT. The placement opens the intake valve sooner and allows some exhaust gas into the intake stroke, which has an EGR effect. It also closes the intake valve sooner, which increases the compression stroke. On a cold engine, opening the intake valve sooner will also warm the intake charge and assist in reducing startup emissions.

Dual Cams

Some newer systems utilize the best of both worlds; they control multiple cams independently of each other. In dual independent systems, the exhaust camshaft is retarded and the intake valve is advanced independent of each other. Doing so maximizes the EGR effect and further reduces pumping losses for maximum efficiency.

Tip: Have a vehicle that is setting VVT or VCT codes? Hear rattling sounds from your cam phaser? You may need a new VVT actuator or solenoid, and TechSmart has you covered with a selection of VVT actuators and solenoids.

One Final Reminder

Hopefully, you now have a better understanding of how your vehicle is more Earth-friendly than the vehicles of yesterday. Still, it’s important to make sure to maintain your vehicle properly, whether it’s using the recommended fluids, changing the fluids at the recommended service intervals found in the owner’s manual, diagnosing and repairing any warning lights, and keeping tires properly inflated. Following the tips will ensure a better driving experience, increase fuel efficiency, and decrease tailpipe emissions.

Kooiman 3

Ryan Kooiman is the Director of Training at Standard Motor Products. In addition to leading SMP's award-winning PTS training program, he is the face of SMP's 'Installation Spotlight' videos on YouTube. He has ASE Master L1, L2, and L3 Certifications, and has had articles published in over 30 periodicals.

There's More Than One Way to Melt a Headlight Harness

by Ryan Kooiman

In the middle of what you thought was a routine headlight bulb replacement, have you ever unplugged the bulb and found a melted connector?

Melted Harness Final

This scenario is something that technicians regularly encounter, whether they’re working on an Acura, BMW, Chevy, Ford, VW, or any make or model in between.  Most of the time, the issue is caused by the OE wire gauge, which is too small (typically 20 gauge) to handle the current drawn by the headlight bulbs. In other cases, the issue is the result of loose terminal connections, which can cause resistance in the circuit and lead to overheating. Still, in other instances, the vehicle may have an “upgraded” bulb, which on the application being used creates more heat than the original. Each of these scenarios can cause the original to melt and fail.

Closeup 3

In the past, the only solution available to technicians was replacing the connector with one similar to the failed part.  This isn’t the most satisfying repair, because the technician must send the vehicle out the door and hope that the repair lasts as long as the original connector.  

Close 4

A Solution That Prevents Melting

Connector Close 1 (1)

Understanding technicians’ frustrations, the team at TechSmart worked to find a better solution for the melted headlight wiring harness problem. The result was a line of headlight wiring harnesses, all featuring high-temp connectors that can withstand extreme heat. Here are a few other features:

  • 14 gauge wire for better conductivity
  • “Plug & play” function allows you to plug harness between the factory harness and new bulb
  • If the original connector is melted, the harness can be used as a pigtail
  • Coverage for the following high-temp bulbs: H1, H3, H4, H7, H11, 9004, 9005, 9006, 9006XS, and 9007

If you’re replacing a bulb and the original harness is not yet damaged, it’s recommended that you install one of these harnesses to prevent a future problem.

Kooiman 3

Ryan Kooiman is the Director of Training at Standard Motor Products. In addition to leading SMP's award-winning PTS training program, he is the face of SMP's 'Installation Spotlight' videos on YouTube. He has ASE Master L1, L2, and L3 Certifications, and has had articles published in over 30 periodicals.