Mazda Tech Tip: Air Conditioning Musty / Mildew Odor

  • Models:
  • 1998 MPV
  • 2002-2003 Protege5
  • 2013-2019 CX-5
  • 2006-2015 Mazda5
  • 2000-2006 MPV
  • 1999-2005 Miata
  • 2007-2012 CX-7
  • 2003-2019 Mazda6
  • 1998-2002 626
  • 1998-2002 Millenia
  • 2007-2019 CX-9
  • 2011-2014 Mazda2
  • 1998-2003 Protege
  • 2006-2019 MX-5
  • 2004-2019 Mazda3
  • 2016-2019 CX-3

A musty odor may come from the vents when the A/C system is operating. It is most noticeable when the A/C is first turned on. This odor is the result of mold growth in the A/C evaporator and case which is caused by condensation, dust, and pollen within the cooling unit. This condition is usually worse during high humidity conditions. 

Mazda Air Cooling Coil Coating is available to encapsulate the mold to reduce odors. If the product is properly applied, it can effectively reduce the musty/mildew odor for up to three years. This treatment provides a durable coating that will aid to prevent biological reactions that lead to odor concerns. 

It is applied to the evaporator in a misted form that is introduced by way of either the cabin air filter, re-circulate door, the blower motor resistor access or the blower motor air intake. TSB NUMBER: 07-002/19 contains the specific instructions for each vehicle. Proper application requires the evaporator surface to be present.

Clean the throttle valve and chamber of the electronic throttle actuator. Nissan recommends the use of a non-chlorinated carburetor cleaner.

Courtesy of Brake & Front End.


2004-2013 Mazda3 Brake Job

The 2004-2013 Mazda3 is based on the Ford global C1 platform, shared with the European Ford Focus and Volvo S40. Nothing is really groundbreaking about the mechanical brake system, but not paying attention to the details can end in a post-brake-job comeback.

A key service issue concerns the hydraulics and ABS system. The older the car, the greater the chance the brake fluid has not been serviced. Over time this can cause issues with the ABS hydraulic control unit.

Front Brakes

For almost 10 years, Mazda used the same caliper, pad and rotor design.
Pads should be replaced when there is 2mm or less of friction material. If the rotors are any thicker, they have enough material on them to last at least one turning on the lathe. The runout specification for these vehicles is .002” and disc thickness variation should be far below .0005”.

Mazda claims repeated panic braking may raise the temperature in some portions of the disc plate by approx. 1,000°C (l,832°F). This temperature is almost near impossible to achieve this side of a high-speed police chase.

The calipers mount to the brackets using caliper guide pins with Allen heads. The sleeves and boots should be disassembled, cleaned and lubricated every time the brakes are replaced. The torque for the guide pins is 21 ft./lbs. and the caliper bracket bolts should be tightened to 75 ft./lbs.

Rear Brakes

All Mazda3 models have rear disc brakes. The calipers mount to the brackets using caliper guide pins with Allen heads. The sleeves and boots should be disassembled, cleaned and lubricated every time the brakes are replaced. The torque for the guide pins is 21 ft./lbs. and the caliper bracket bolts should be tightened to 55 ft./lbs.

Mazda uses a hand brake that is incorporated into the rear caliper, and a couple of systems are employed to retract rear pistons. The later-model cars require the familiar method of turning the piston clockwise while applying pressure, where others will have a plug on the back side of the caliper that provides access for an Allen wrench to facilitate retracting the piston. Be careful as you retract the piston.

After the pads are replaced, pump the pedal and adjust the parking brake mechanism in the rear calipers. If the level has too much travel, perform the following steps:

  1. Pump the brake pedal a few times.
  2. Remove the service hole cover of the rear console.
  3. Turn the adjusting nut and adjust the parking brake lever.
  4. After adjustment, pull the parking brake lever one notch and verify that the parking brake warning light illuminates and the rear brakes do not drag.

ABS/DSC Diagnostics and Repair

The Mazda3 comes in two styles, ABS and ABS with Dynamic Stability Control (DSC). Both systems connect to other vehicle components via a high-speed serial data bus. The DSC system ties more components together (like a yaw/pitch sensor and steering position sensor) onto the bus.

If you are seeing communication-related DTCs, it is essential that you fully diagnose problems with the system before you start replacing sensors and modules. Some of these vehicles have been on the road for more than six years and the connections will be starting to corrode and fret.

One of the main facilitators of ABS/DCS problems are the connectors, especially under the hood where the control/modulator unit connects. Being able to measure values at the connectors and observe data on a scan tool is essential for diagnosing problems.

The biggest ABS issue with the three generations of Mazda3s is power. With some higher mileage vehicles, the battery cables, wiring from the power distribution box or the ground connection (behind the driver’s side headlight at G02) can have enough resistance so the voltage drops below 8 volts. When this happens, the ABS module cuts control and the electronic brake distribution system is disabled.

If a modulator/control unit is replaced, the pressure sensors must be recalibrated with a scan tool that is able to communicate with the chassis/ABS module. If this is not performed, it can result in brake failure and lock up.

If you have DTCs C1141, C1142, C1143, C1144, C1233, C1234, C1235 or C1236 (ABS wheel-speed sensor/ABS sensor rotor), chances are something is wrong with the wheel bearings. Another cause for these codes could be an accumulation of metal debris on the sensor. The front bearings are press-in cartridge-style units. Rear wheel bearings are hub units. In the front, the tone ring, or encoder, is on the inner seal of the bearing and the sensor is mounted in the knuckle. The parameters for these codes to be set include abnormalities in the signal such as a weak signal or large differences in the value when compared to the other sensors.

If you have DTCs C1145, C1155, C1165 or C1175 (open sensor), it could be damaged wiring or a failed sensor that is the problem. If you have more than one, chances are there is a problem with the connection at the control unit or in the front or rear harnesses of the sensors.

These DTCs will usually clear themselves after repairs are made and the vehicle is driven above 6.2 mph when the self-diagnostic check is performed.

Some customers may report a slight clunk, bang or jolt from the front of the vehicle. This concern will most likely occur during the vehicle’s first forward movement and after the vehicle sits for a few hours and/or a cold soak. This is a normal operating noise of the ABS system.

If you encounter a customer complaint for this concern, explain that the noise comes from the ABS/TCS/DSC “Malfunction Detection Function” initial check. The initial check is a necessary function to ensure the normal operation of the ABS/TCS/DSC system. This initial test function occurs during the vehicle’s first forward movement and when the vehicle reaches approximately 6.2 mph.

Article courtesy Brake & Front End.


Mazda Tech Tip: Vibration Felt Through The Floor/Seat/Steering Wheel

2013-’16 CX-5 with automatic transmission
2014-’17 Mazda 6 with automatic transmission


Some customers may complain about a vibration that is felt through the floor, seat and/or steering wheel while driving under moderate acceleration, at speeds of approx. 25-30 mph (40-50 km/h). The vibration is more noticeable when driving on smooth, flat roads.

The vibration may be caused by wear on the inner surface of the tripod joint case (inner side of front driveshaft). To eliminate this concern, a coating has been applied to the inner surface of the tripod joint case to improve wear resistance.

Repair Procedures:
1. Verify the customer concern.
2. Replace the inner joint set for the left and right drive shafts.
3. Verify the repair.

Courtesy of Mitchell 1.


Alabama High Schools May Become Training Grounds For Toyota-Mazda Plant

The curriculum in auto technology classes in the Decatur, AL, area will help prepare students to obtain jobs at the Toyota-Mazda plant.

From Deangelo McDaniel’s article on the Decatur Daily website:

A joint venture between Toyota and Mazda that is expected to generate as many as 4,000 jobs may turn Decatur-area schools into training grounds for the plant.

Students who attend the auto technology classes at Brewer High School have been working on Toyota engines for two years, but Morgan County schools, as well as other school districts in the area, said they will alter class offerings once they learn what is required to get jobs at the Toyota-Mazda plant.

The Japanese automakers announced plans Wednesday to open the $1.6 billion manufacturing facility in the Huntsville-annexed Greenbrier part of Limestone County by 2021. It will have the capacity to produce 300,000 vehicles a year. The average salary will be $50,000 a year.

Click HERE to read the entire article about the Toyota-Mazda training programs on the Decatur Daily website.



Drifting: An Education

The fixed up Miata ready for the April 2017 Driftchitown event. Photo by Driftchitown.

It’s a special moment seeing your project car come to life on the track, but it’s not every day you get to see your auto instructor crash it. For a dozen Rolling Meadows High School auto technology students, their drift car project is continuously a work in progress; getting better and better after each race.

In the winter of 2017, automotive technology instructor Joel Dufkis brought a beat up Mazda Miata to his classroom in Rolling Meadows, Illinois, with the goal of teaching his students how to build a racecar, while getting some drifting chops himself.

Students removing soundproofing, seam sealer and paint from the floor to prep for a roll bar install. Photo by Joel Dufkis.

“I decided we needed some kind of project or something to do with the kids to try and do different things besides just repairing stuff,” says Dufkis.

“There’s an event called Driftchitown where they hold drift events at the Great Lakes Dragaway in Union Grove, Wisconsin. I saw that they are having events there so I figured we could take this Miata and build it into a drift car, take it up there and showcase the students’ skills and show them how to build a racecar.”

Students with the new tubular front end that they created. Photo by Joel Dufkis.

From Miata to ‘Mazdarati’

Using a play on words to jokingly compare their budget Mazda Miata to the sporting prowess of a Maserati, the students dubbed their project the “Mazdarati.”

Tony Puglia painting the car. Photo by Joel Dufkis.

Taking a Miata and turning it into the drifting Mazdarati took some trial and error.

“So when we got the car ready for the first time, we cut the springs to give it a little bit of a lower center of gravity, and we did a little bit of body work just to make it look better,” says Nicholas Wiltse, a senior at Rolling Meadows High School.

“We pretty much repainted the whole driver’s side and back trunk area of the car,” adds fellow senior Tony Puglia.

The beginnings of the Mazdarati. Photo by Joel Dufkis.

Beyond cosmetics, safety was also a concern. Dufkis and his students completely designed, bent and welded a custom roll bar for the Miata. The students also cut out the floor and welded in new mounts for a Kirkey Racking Seat.

After these changes were complete, Dufkis and his students took the Mazdarati to Driftchitown in April for their first drifting event. As the official Mazdarati driver, Dufkis drifted the car right into a concrete wall, chopping of the entire front end in the crash.

Cutting the springs proved to be problematic, causing a snap-oversteer situation that meant trouble combined with the car’s open differentials.

Getting Back on Track

Following the crash, the students pulled out the engine and drivetrain, cut out from the strut towers forward and created a tubular front end. On a tight budget to get parts, Dufkis found Miata body parts on Craigslist, but also came back with some used coilovers from the Craigslist seller’s own project Miata.

The aftermath of a small collision with the wall at the first event. Photo by Joel Dufkis.

Dufkis also reached out to various companies to help sponsor the car through discounts that could get his students the parts they needed. Delinquent Industries hooked them up with steering knuckles to help the wheels turn more for optimum drifting. Other sponsors included Bend-Tech, Bauer Limited, Gates, and Titan Wheel Accessories.

The students also put a new radiator in, installed an eBay header and depowered the power steering rack to create a manual rack (since the power steering pump was a little smashed up from the crash).

For a cooler running Miata, they also modified a Hawley Performance coolant relocation kit.

The next race in August went a lot better, and was crash free, but getting on the track always presented opportunities to make the Mazdarati even better.

“In the August event we found out that the inside of the tires were rubbing on the lower control arms. So we had to grind those down a little bit give it a little bit more clearance for when the wheels were at full lock,” says Nicholas Wiltse.

Nicholas Wiltse cutting the front crash bar out in order to make a bash bar. Photo by Joel Dufkis.

What’s Next?

Prepping for a race in October, the students had a running list of modifications to complete including installing extended lower ball joints to give the car more camber, allowing the tires to sit flatter on the ground in turns. In the winter they are looking at installing a turbo kit and possibly a rear mount radiator.

Dufkis’ father Len Dufkis going over instructions with the students on how to paint the car. Photo by Joel Dufkis.

“We’re basically going to build pretty much everything we can from scratch,” says Dufkis.

For the students, the continuous work offers something beyond everday learning.

“It’s not just doing oil changes and brakes, it’s more modifying the car and seeing what works and what doesn’t work, and, what’s better for drifting,” says Tony Puglia. “And a lot of us can’t afford a car to make a project car and so this is also fun.”

“I liked working as a team,” adds senior Jarrett Donato, referring to his favorite part of the project so far. “And then finally getting it up and running…I like how we all had stuff to do to make things better and finally seeing something that we did work on the track.”

(Left to Right) Tony Puglia, Nicholas Wiltse, Kamil Halaj and Jarrett Donato at the 1st Driftchttown event in April the first Driftchttown event in April. Photo by Joel Dufkis.

Featured News

Mazda To Unveil New Prototype Race Car At Los Angeles Auto Show

In a recent press announcement, Mazda said that it will be introducing a new Prototype race car at the upcoming Los Angeles Auto Show which begins November 16.

The new Prototype will compete in the Daytona Prototype international (DPi) class at the top level of the IMSA WeatherTech SportsCar Championship in 2017.

We don’t know many details at this point, but since the discontinuation of the long running Daytona Prototype (DP) class at the end of this year, there has been a lot of speculation about the new cars. According to IMSA, all DPi cars will use the same chassis, suspension and many other components as LM P2 cars competing in championships. The DPi car will be a standard ACO/FIA homologated 2017 LM P2 Prototype chassis from one of the four approved constructors (Dallara, Onroak Automotive, ORECA or Riley/Multimatic) fitted with IMSA-homologated, manufacturer-designed and branded bodywork and engines.
Masahiro Moro, President and CEO, Mazda North American Operations, John Doonan, Director, Mazda Motorsports North America, Ken Saward, Sr. Manager of Design, Mazda Design Americas will all be in attendance to unveil the car along with current Mazda Prototype drivers Jonathan Bomarito, Tom Long, Joel Miller and Tristan Nunez.

Article courtesy Speedville.
Featured News

Mazda Announces MX-5 Miata RF Launch Edition

The 2017 Mazda MX-5 Miata RF made its debut at this year’s New York International Auto Show. The MX-5 RF was introduced with a color combination that will be exclusive to MX-5 RF versus the MX-5 soft top: Machine Gray Metallic paint color, Auburn Nappa leather interior trim with a hand-painted black roof panel, based on the Grand Touring trim level.

Now, the show car is set to become the MX-5 RF Launch Edition, limited to 1,000 vehicles in the U.S. and destined for Mazda’s most loyal customers.

Initially, Mazda North American Operations (MNAO) will open up the preorders to a select group of customers who will be notified via email and will have a specific window of time to preorder the MX-5 RF Launch Edition before ordering opens to the general public*. Customers who opt to purchase an MX-5 RF Launch Edition will have but one option available — SKYACTIV-MT six-speed manual or a six-speed automatic transmission — with each vehicle being made to order.

“MX-5 has enjoyed 27 years of being the world’s best-selling roadster, being named 2016 World Car of the Year and World Car Design of the Year and receiving hundreds, if not thousands, of other accolades,” said Robert Davis, senior VP, U.S. Operations, MNAO. “Rarely does any automaker have a vehicle that garners the sort of loyalty and enthusiasm MX-5 generates — something we don’t take lightly. MX-5 RF is the next chapter of this storied model line, and we can’t think of a better way to give back than to first offer this bespoke Launch Edition to those who have stuck with us, believing in our mission to deliver the best-driving vehicles on the road.”

Outside of the exclusive color combination, MX-5 RF Launch Edition customers will receive a custom-designed, numbered 42mm Tourneau watch to complement their cars.

For those who may miss out on purchasing an MX-5 RF Launch Edition, other retractable fastback models will be available with many of the same colors and interior combinations—just not the Machine Gray Metallic exterior color on the Grand Touring trim level with the black roof, Auburn Nappa leather interior and badging. While the 2017 MX-5 RF Launch Edition is based on the Grand Touring trim level, other MX-5 RF models are expected to arrive at U.S. dealerships in the first quarter of 2017 in either Grand Touring or Club trim levels.

Specific timing for MX-5 RF Launch Edition ordering, as well as pricing, will be announced in the coming weeks.

For more information, visit

Article courtesy Speedville.


Mazda Pressure Breather Hose Frozen, DTC P0451

Figure 1

Models: 2010 Mazda3, 2010 Mazda CX-7

Condition: Some vehicles may experience a MIL on with only OTC P0451 stored in the memory. This is caused by water entering and freezing in the atmosphere breather hose of the fuel tank pressure (FTP) sensor. For Mazda3s, this happens when the vehicle is washed in a high-pressure car wash. For the CX-7, this happens when the vehicle is driven on a wet road. To correct the problem, a modified breather hose has been adopted.

Customers having this concern should have their vehicle repaired using the following repair procedure.

Repair Procedure:

1. Verify customer concern.

2. Remove and inspect both the FTP sensor (A) and atmosphere breather hose (B), if applicable, from the vehicle, and inspect for water and/or ice. End (C) goes to the fuel tank and end (D) goes to the canister. See Figure 1.

• If water is found, drain the water from the FTP sensor by shaking it out.

• If ice is found, warm up the sensor and then drain.

Caution: Do not use pressurized air to drain the water from the FTP sensor, otherwise the sensor could be damaged.

3. Install a modified breather hose (B1) as shown.

4. Reinstall the FTP sensor.

5. Using the M-MDS, confirm that the FTP sensor PIO voltage readings are within 2.5-3.6 volts.

• If the FTP sensor voltage readings are within range, repair is complete.

• If the FTP sensor voltage readings are NOT within range, the sensor has been damaged and needs to be replaced.

Courtesy of ALLDATA.


Mazda Truck TPMS Service Precautions


2006-2010 MX-5, 2004-2010 RX-8, 2007-2010 CX-7, 2007-2010 CX-9, 2004-2010 Mazda3, 2004-2010 Mazdaspeed3, 2006-2010 Mazda5, 2008-2010 Mazda6

Mazda truck TPMSService Precautions

1. DO NOT use metal stem caps. Some vehicles may experience the aluminum valve stem (B) breaking off of the TPMS wheel unit (C) when removing aftermarket valve stem caps during procedures such as routine checking of air pressure in tires.

TPMS sensor nut (A): Initial torque 67-75 in-lbf (7.5-8.5 Nm)

Some aftermarket valve stem caps are made of metal or have thread inserts that are made of metal. Examples of these types of aftermarket valve stem caps are shown to the right. When metal and aluminum are together in such a condition, galvanic corrosion occurs between the aluminum valve stem of the TPMS sensor unit and the metal threads of the valve stem cap. This corrosion can cause them to fuse together, becoming difficult to remove by hand. When more force is used to remove the valve stem cap, the aluminum valve stem of the TPMS sensor unit will break off and the TPMS sensor unit will need to be replaced.

Mazda truck TPMS stem cap typesTypical aftermarket valve stem caps:

(A) – Metal

(B) – Chrome over metal

(C) – Aluminum with metal insert

This service bulletin can aid in informing customers of the damage that may be caused to the TPMS sensor units by installing these types of valve stem caps. Advise customers to use aluminum or plastic caps ONLY.

Also, ensure that the caps they choose to install DO NOT have a metal thread insert.

mazda-truck-tpms-32. Torque TPMS sensor nut (A) and valve core (B) properly. Excessive torque on TPMS sensor nut and/or valve core may result in damage/breakage of the valve stem.

NOTE: The torque of the TPMS sensor nut slightly decreases after filling the tire with air. 17.7-26.6 in-lbf (2-3 Nm) is acceptable at this stage. DO NOT retighten after that.

3. Replace TPMS sensor nut when TPMS sensor (C) is detached. The TPMS sensor nut must be replaced with seal washer and seal when TPMS sensor is detached from the wheel.

1) TPMS sensor nut

2) TPMS sensor components

3) Seal washer

4) Seal

5) TPMS sensor

Courtesy of ALLDATA.

Featured News

Mazda To Race With New MZ-2.0T Engine


The two-car Mazda Prototype race team will be powered by the new gasoline-fueled MZ-2.0T engine this season in the IMSA WeatherTech SportsCar Championship. The engine has been in development for much of the past year and has completed nearly 4,000 test miles prior to the “ROAR before the 24” test session at the Daytona International Speedway.

The MZ-2.0T earned its name from its configuration: “MZ” refers to Mazda, “2.0” references its two-liter capacity, while “T” is a nod to the turbocharger. The inline, four-cylinder engine is built upon a similar foundation of the MZR-R engine that was developed by Mazda and Advanced Engine Research Ltd. (AER) for sports car racing beginning in 2006. In addition to the new Prototype engine, Mazda works with AER on the current version of the MZR-R engine that powers the entire field in the Indy Lights series, the top rung of the Mazda Road to Indy.

John Doonan, Director, Mazda Motorsports North America
“We gained immense knowledge from three years of racing a stock-block diesel engine. That knowledge will improve the next generation of Mazda diesel engines. But, with the impending rules changes in 2017 [which will not allow a diesel-fueled option], a purpose-built racing engine was our best choice to reach our long-term goals and contend for race wins and championships. After extensive testing, the MZ-2.0T is not only very fast, but reliable as well. There was no off-season for this team, as they’ve worked incredibly hard to prepare for the season. Mazda loves to race, and we couldn’t be more optimistic about the prospect of this engine and our team.”

Jonathan Bomarito, Driver, Mazda Prototype team
“The drivability of the engine is incredible. The first thing you notice is how smooth the power is delivered in every gear through the RPM range. There is great low-end torque with zero turbo-lag, which is very impressive. All race tracks are different and the gearing is never perfect for every corner, so having an engine where you can short-shift or stretch a gear longer is very important. The MZ-2.0T does this easily.”

Marcus Shen, Chief Engineer, Mazda Prototype team
“This engine has transformed everything for us. Obviously, it’s more powerful so we’re going faster. Once you go faster, the aerodynamics work very differently – we have much more downforce – and the chassis works better. It’s not just straightaway speed, the engine has improved every aspect of our overall performance.

“A gasoline, direct-injected engine – like many of the Mazda passenger cars – helps with the horsepower and throttle response and yet still produces great fuel economy. When the driver puts the pedal down, it goes. It’s creating roughly 285 horsepower per liter, which is much higher than the estimated 110 horsepower per liter of the 5.5-liter V8 Daytona Prototype engines.”

The Mazda Prototype team features two entries: the No. 55 car (numbered in honor of the 25th anniversary of Mazda’s Le Mans victory) with drivers Jonathan Bomarito and Tristan Nunez, and the No. 70 car with Joel Miller and Tom Long driving. For the Rolex 24, current Indy Lights champion Spencer Pigot will join the No. 55 team, while Ben Devlin will return to the team to drive the No. 70.


Specifications: MZ-2.0T Engine

• Capacity: 2 liters
• Cylinders: 4 inline cylinders
• Horsepower: approximately 570 horsepower (285 HP per liter)
• Maximum RPM: 9,000
• Injection: Direct injection, multi-hole, spray guided injectors
• Fuel Rail Pressure: More than 1,500 PSI
• Compression Ratio: 13.5:1
• Peak Manifold Pressure: 2.6 bar (37.7 PSI)
• Turbocharger: single Garrett Motorsports unit, 46mm restrictor
• Exhaust Manifold: tubular 4-2-1 manifold
• Intake Manifold: bespoke carbon fiber
• Oiling System: bespoke dry sump system
• ECU: LIFE engine management ECU

Courtesy Speedville.