Many late model Subaru vehicles are equipped with ABS braking systems. The added complexity of these systems provides an additional incentive for following the recommended brake fluid replacement interval of 30 months or 30,000 miles. Brake fluid accumulates water and other contaminants over time. These contaminants can attack the internal parts of the brake system, compromising its performance and possibly causing brake failure.
The brake master cylinder has a semi-transparent reservoir, making it possible to check the fluid level without removing the reservoir cover. This minimizes the exposure to outside air and limits the amount of moisture that can reach the brake fluid. The fluid level will drop as the brake shoes and pads wear, but the reservoir is large enough to compensate for these changes. If the fluid level is very low, it’s a sure sign the brake pads or shoes are nearly worn out, or there is a leak in the brake system.
Note: When the brake fluid level in the reservoir tank is lower than the specified limit, the brake fluid warning light in the combination meter will come on.
Subaru warns against mixing brake fluids from different manufacturers. Doing so may degrade the quality of the fluid. Only DOT 3 or 4 brake fluid should be used in any Subaru vehicle preferably Subaru brake fluid if you are not going to do a track day build. Consult the service manual for vehicle specific brake bleeding procedures.
A variety of antilock brake system (ABS) have been installed in Subaru vehicles since the first systems were installed in the 1990 Legacy. In the sections that follow, we’ll give you a brief overview of each system and explain proper diagnostic techniques.
The original Subaru Legacy Antilock Brake System (ABS) was licensed by Bosch and manufactured by Nippon ABS, Ltd. The system electronically controls brake fluid pressure supplied to the brake system. This control helps to prevent “wheel lockup” during braking on slippery surfaces and emergency situations. The system includes a fail-safe feature, which indicates a malfunction by illuminating the warning lamp. The system is then returned to a conventional power brake system. The four channel system provides accurate individual wheelspeed control and improves the directional stability of the vehicle during braking.
A tone wheel is attached to each wheel hub and rotates at the same speed as the hub. The magnetic speed sensor is mounted in the axle housing. The notched tone wheel acts as a reluctor which modulates the magnetic field of the speed sensor. The tone wheels are individually replaceable.
The speed sensor provides an alternating voltage signal to the ECU. The alternating voltage and frequency corresponds to wheelspeed.
There’s no easy way to check the inside of a fuel filter for dirt or other contamination buildup. That’s why a 30 month or 30,000 mile replacement interval is prescribed. If the customer happens to buy a tank-load of bad gasoline before reaching this interval, it will be necessary to replace the fuel filter ahead of time. There’s no way to clean the filter—replacement is the only option. Remove the battery negative cable before you begin work on the fuel filter. Remember gasoline is a very flammable substance.
The fuel filter is just one small part of the fuel system. The fuel system includes many sections of steel and rubber fuel line that run the length of the vehicle several times. The fuel pump, fuel tank, and fuel pressure regulator are just a few of the other parts of the fuel system. While you’re replacing the fuel filter, don’t forget to check the condition of the rest of the fuel system.
If any of the rubber hoses (especially the ones that were opened up to replace the filter) look damaged or frayed, they must be replaced before they can cause any further damage. Weak fuel hose clamps should be replaced, and the new ones must be properly positioned and tightened to specification.
Here is the step by step guide to installing the JDM Automatic Intercooler STi switch. For those of you wondering the advantage of upgrading to the JDM automatic intercooler switch is that it essentially works as a on/off switch for the STi intercooler sprayer. So there is no more constant pushing of the sprayer button. Push the button once to turn it on, and again to turn it off. However, it will empty out your intercooler sprayer tank very quickly if you keep it on.
Here is the switch we are going to be installed:
1.) Pop out the fuse box panel. The fuse box panel is located underneath and to the left of the steering wheel.
2.) Use your fingers to depress the tab on the button of the button to pop it out.
3.) Pull the switch out of the dash.
4.) Depress the tab on the back of the plug to remove the switch.
Subaru of America does not recommend the use of any engine oil additives in any Subaru engine crankcase. Subaru engines are designed to be lubricated with normal petroleum or synthetic-based engine oils in the viscosity and grade indicated in the Owner’s Manual for each specific engine and usage condition. Subaru has not tested the effectiveness or compatibility of any engine oil additives.
However, the use of such oil additives does not void warranty coverage. Usage of any additive is at the owner’s discretion. Since Subaru has not tested the compatibility or effectiveness of any such additives, should an engine failure occur that is determined to be caused by the incompatibility or performance of such an additive, the vehicle owner would be be referred to the additive manufacturer to request reimbursement of the cost of the repair.
If you are using oil additives to try to save a leaking headgasket it’s better to just suck it up and just either install new headgaskets yourself or have the work done by a trusted mechanic.
Either use Subaru’s OEM synthetic motor oil or use Rotella T6 motor oil. If your Subaru is still under warranty by Subaru it’s best to get your oil changed by a Subaru dealership and avoid introducing oil additives into your boxer engine. Even if it’s Subaru’s official stance that they won’t void warranties if oil additives are involved it doesn’t mean that they won’t if there is more evidence of engine “tampering”. Avoid anything that could potentially cause a dealership to refuse service to your car in the future.
Otherwise you might have a expensive repair bill if your Subaru boxer engine spins a bearing or has a ringland failure. Of course adding aftermarket parts like an exhaust or intake along with a tune will greatly increase the justification of a Subaru dealership to void a warranty more than adding oil additives.
Not adding oil additives can be another step in avoiding a void warranty from Subaru of America. On a final note remember that Subaru can scan your ECU for previous tunes even if you went back to a stock tune and will void a warranty for that.
Vehicle maintenance is an important factor for proper vehicle operation. It’s the vehicle owner’s responsibility to ensure that fluid levels (engine oil, coolant, etc.) are checked frequently, in accordance with the instructions in the Subaru owner’s manual. However, many ‘gas and go’ vehicle owners may not take the time to fulfill these basic responsibilities. This places added importance on the performance of periodic maintenance services. If the Subaru owner isn’t looking after his vehicle, it falls to the automotive service professional to ensure that proper maintenance procedures are performed.
The frequency of scheduled inspection and maintenance services required by late model Subaru vehicles is minimal when compared with vehicles of the past. For example, even the very commonly used term ‘tune-up’ has lost most of its original meaning. In the old days, a ‘tune-up’ meant fresh spark plugs, points and condenser, and basic engine adjustments such as timing, idle mixture and idle speed. Modern technology has eliminated the need for many of these adjustments and replacement parts. However, the tune-up is alive and well— only its definition has changed.
While the number of vehicle items requiring regular replacement has decreased, the number of items needing periodic inspection has not. Whether you call it a tune-up or something else, this service offers an excellent opportunity for all engine belts, hoses and ignition wires to be checked for wear and tension. Old tune-up standbys like spark plugs, fuel and air filters are still on every Subaru vehicle and still require periodic inspection and replacement as necessary.
The same applies to all other items on the Subaru maintenance schedule. The important thing is to carefully inspect each item. If additional corrective action is required, now is the time to find out.
All late model Subaru four cylinder engines employ a “waste spark” ignition coil system. Each time the ignition coil fires, it provides a spark to two cylinders at exactly the same time. Since only one of the two cylinders is on the compression stroke when the coil fires, the spark to the second cylinder (which is on the exhaust stroke) is “wasted. ”
The ignition coil sits on top of the intake manifold and is divided into two halves. One half provides the spark to the number 1 and 2 cylinders, and the other half provides the spark to the number 3 and 4 cylinders. Instead of the familiar single secondary coil terminal, this coil has four secondary coil terminals.
Testing methods for this type of coil are slightly different from what you might be accustomed to as well. Using an accurate DMM, inspect the following items, and replace the ignition coil if it is found to be defective:
• Primary resistance
• Secondary resistance
Caution: If the resistance is extremely low, this indicates the presence of a short circuit.
This is a list of the OBD-2 diagnostic trouble codes for Subaru Impreza, WRX, STi, Forester, and Legacy.
P0031 Front oxygen (A/F) sensor heater circuit low input
P0032 Front oxygen (A/F) sensor heater circult high input
P0037 Rear oxygen sensor heater circuit malfunction
P0038 Rear oxygen sensor heater circuit high input
P0065 Air assist injector solenoid valve malfunction
P0066 Air assist injector solenoid valve circuit low input
P0067 Air assist injector solenoid valve circuit high input
P0100 Mass or Volume Air Flow Circuit Malfunction
P0101 Mass or Volume Air Flow Circuit Range/Performance Problem
P0102 Mass or Volume Air Flow Circuit Low Input
P0103 Mass or Volume Air Flow Circuit High Input
P0104 Mass or Volume Air Flow Circuit Intermittent
P0105 Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction
P0106 Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem
P0107 Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input
P0109 Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent
P0109 Intake Air Temperature Circuit Malfunction
P0111 Intake Air Temperature Circuit Range/Performance Problem
P0112 Intake Air Temperature Circuit Low Input
P0113 Intake Air Temperature Circuit High Input
P0114 Intake Air Temperature Circuit Intermittent
P0115 Engine Coolant Temperature Circuit Malfunction
P0116 Engine Coolant Temperature Circuit Range/Performance Problem
P0117 Engine Coolant Temperature Circuit Low Input
P0118 Engine Coolant Temperature Circuit High Input
P0119 Engine Coolant Temperature Circuit Intermittent
P0120 Throttle/Petal Position Sensor/Switch A Circuit Malfunction
P0121 Throttle/Petal Position Sensor/Switch A Circuit Range/Performance Problem
P0122 Throttle/Petal Position Sensor/Switch A Circuit Low Input
P0123 Throttle/Petal Position Sensor/Switch A Circuit High Input
P0124 Throttle/Petal Position Sensor/Switch A Circuit Intermittent
P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control
P0126 Insufficient Coolant Temperature for Stable Operation
P0128 Thermostat malfunction
P0130 O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
P0131 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)