Tech Tips February 2016 (TIPS 0216)

TECH TIPS FEBRUARY 2016

TECHNICAL SERVICE BULLETIN

18 WVX-34 (LOWER CONTROL ARM CORROSION) REMINDER

As with any campaign, it is critical for ALL  outlined procedures to be followed exactly as they are written. In the case of WVX-34, Front Lower Control Arm (Transverse Link) Corrosion, a step which should NEVER be skipped is the punch testing of the upper side of the control arms. BOTH UPPER AND LOWER SIDES OF THE CONTROL ARMS MUST BE PUNCH TESTED AS DESCRIBED IN THE WVX-34 SERVICE PROCEDURE.  Never assume just because the bottom of the control arm(s) passed the punch test that the upper portion does not require testing, IT DOES  . Failure to test this area may result in not finding a weakness in this area which could eventually lead to a failure of the control arm. It is also VERY IMPORTANT  to follow the Service Procedure instructions for proper application of both the Nox-Rust oil and Nox-Rust anti-rust wax products. Don't put yourself, your retailer, your customers, or other drivers on the roadways at risk. Always follow ALL  procedures in every campaign (or Service Bulletin) completely.

15 AUTO DIMMING AND HOME LINK ACCESSORY MIRROR WIRING HARNESS TROUBLESHOOTING

If you are diagnosing an electrical fault on a vehicle, do not forget to check all of the associated systems involved with the circuit in question. One example would be inoperative back-up lights on a 2016 Forester with a short to ground in power supply circuit FB-35. If the vehicle is equipped with the Auto Dimming and Home Link accessory mirror, there is a possibility when the map light or Eye Sight® panel was reinstalled, the wiring harness could have been damaged when inserting the retaining fasteners if not routed correctly as shown in Figure 1. Outlined below is the wiring diagram, connector identification, and associated circuits involved with this particular scenario.

As you can see, there are multiple components that can be affected on this 2016 Forester if the roof harness or Auto Dimming and Home Link accessory mirror harness is damaged. Another symptom of this damage, shown in figure 5, can be found in Service Bulletin 15-173-14 which is applicable to the 2014-2015 Forester models. Information found in this bulletin includes excellent material pertaining to damaged exterior auto dimming mirrors with approach lighting caused by a short to ground in the interior auto dimming mirror harness.

Service bulletin 15-173-14 also includes detailed images of the harness damage, along with auto dimming mirror circuit testing when applicable. If inspecting this harness for damage, or replacement of the harness is necessary, it is required that the harness be routed correctly. Figures 6 and 7 show the proper routing and placement of the roof harness and accessory mirror harness.

Keep in mind that not all vehicles are equipped with the accessory Auto Dimming and Home Link mirror but could exhibit similar symptoms if the factory roof harness is damaged. In order to eliminate the roof harness, a simple test would be to refer to the applicable Service Manual and use the split-half troubleshooting technique on the circuit in question.

02 ADDRESSING ACCESSORY DRIVE BELT NOISE

Whenever addressing a squealing or chirping-type sound from the engine compartment isolated as coming from an accessory drive belt, it is important to determine the root cause of the condition. In the past, especially when "V" belts were common, unless an obvious cause was identified, often times a belt dressing or other form of cleaner / lubricant was applied to the belt which TEMPORARILY eliminated the noise addressing the customer concern. Now that ribbed or serpentine belts are the standard, lubricants or conditioners like these should never be used. The Service Manual even indicates "Do not use the V-belt (sic) if there is any oil, grease or coolant on the belt." If the belt needs to be tested, FHI recommends that only a light spray of pure water be applied to the belt in order to see if the characteristics of the sound changes or not. The belt itself, in addition to items such as the tensioner, accessories, idlers, and even simple adjustment make up the list of items which may cause belt noise conditions. This makes the need to identify the root cause extremely important to help avoid repeat repair attempts and most importantly, dissatisfied customers.

To summarize, although these types of products (belt dressings, cleaners, and lubricants) are readily available and in some cases commonly used, it is NOT RECOMMENDED to use any kind of belt dressing product or lubricant on a Subaru accessory drive belt. In the event the belt becomes contaminated, it should always be replaced. Cleaning and re-use is not recommended. Always keep the best interests of your customers in mind by identifying the root cause of the condition and repairing it properly the first time.

07 2016 IMPREZA / CROSSTREK TELEMATICS AND "D-CHECK" FUSE CLARIFICATION

Some 2016MY Crosstrek and Impreza models are now available with the optional Telematics system. We have received a number of reports from the field describing what seems to be some confusion between the 10-amp fuse for the Telematics system and the 10-amp "D-Check" (Transit or "PDI") fuse. First and foremost, there is NO need to do anything at all with the 10-amp Telematics fuse. Although the 2 fuses are the same red color, amperage rating and located relatively close to each other in the underhood (M/B) fuse box as shown in the bottom photo below, the Telematics fuse should be left alone.

The second photo shows the location of the 10-amp "D-Check" (Transit or "PDI") fuse. During Retailer PDI, this fuse must be removed from the M/B and stored in the empty slot in the fuse box cover. Prior to removing this fuse, when the ignition is "ON", the Check Engine light will flash rapidly. Photo (1) below shows the fuse in the "transit" position and (2) the location where it belongs after removal during PDI.