Ford Trucks and SUVs

Diagnose Automatic Transmission Problems Know What You're In For By Matthew Wright, About.com There are a few words in the language of auto repair that make car owners want to crawl back into bed, and "transmission" is at the top of the list. There's something about that mysterious box underneath your car that incites fear. Unfortunately, most repair shops know this, and will take advantage of the situation by reaching deep into your pocket. Before you hand over your keys and a blank check, brush up on the simple end of automatic transmissions. If something is seriously wrong, at least you'll be armed with enough knowledge to avoid being overcharged, over-repaired or straight ripped off. Sometimes it's easy to diagnose automatic transmission problems. Your transmission is a remarkable contraption. Somehow it can shift your car from gear to gear, knowing how fast you need to go and how quickly you need to get there. What goes on inside is a mystery to most. Unless your thirst for automotive knowledge borders on compulsive, you can leave it a mystery. The basics will be enough to have an intelligent (which translates to "not about to be ripped off") conversation with your mechanic. Basic Parts of a Transmission

While there are many, many little parts inside, your transmission is essentially made up of a few key parts of systems. · Bell Housing: This is the cone shaped metal case that you can see when you peek underneath your car. If you have a front-wheel-drive car it's stuck on the side of the engine under the hood. If your car is rear-wheel-drive, the tranmission will be mounted underneath the car behind the engine. · Gears: Even though you're not shifting them, an automatic transmission has gears. They are broken into main gears and planetary gears. You need all of these to be able to drive. · Fluid: Transmission fluid is very important to an automatic transmission. All of the magic happens in the fluid. Most cars come with red transmission fluid, good to know if you are looking for a leak. · Filter: All of that fluid has to be clean for your car to shift gears at the right time. To keep things fresh, your transmission has a filter to catch any gunk. Now that you know a little about what's happening in there, you can try to figure out why your transmission is acting up, or at least understand what your mechanic is talking about while he tries to make your bill into his new fishing boat. Transmission problems fall into two very similar categories: · Won't go. · Won't go smoothly These two groups of problems are caused by the same faults in your transmission, so whichever your car is doing, the following applies. Is your fluid level correct?

It's important to check your transmission fluid at least twice a year. Not only can a low fluid level cause your car to shift poorly, it can eventually lead to transmission damage, and a costly repair. If your car seems to be losing fluid on a regular basis, you may have a leak. Is your transmission leaking?

Checking for leaks isn't as trying as it may seem. The transmission is a closed system, so there are only a few places that can spring a leak. Unless it's been changed to a non-dyed fluid, your car will have red transmission fluid. Here are a few places to check for leaks: · At the filler tube base. · At the drain hole underneath the transmission. · Between the transmission and the engine. · At the selector shaft - the rod that connects your gear shift to the transmission. · Speed sensor mounting point. This will either be your cable screwing into the transmission housing or an electronic sensor bolted to the housing. · The radiator. If your car has a transmission cooler, it's possible that a leak will cause transmission fluid to leak into the radiator fluid. They don't mix well, so you'll see it floating around in there. Is your filter clogged?

Your transmission's filer is vital to its performance. If you haven't replaced your filter in a while (or ever for a lot of us), be sure to do this before you start talking about rebuilds or replacements. Most transmission problems can't be fixed by the average do-it-yourselfer. There are just too many specialized tools and pieces of equipment you'll need, and buying this expensive gear just to screw up your first three tries at fixing the thing just doesn't make too much sense. Now that you're in front of the firing squad, it's time to drop some knowledge on your fix-it guy. Tell him what the car's doing. Then tell him what you found out when you inspected the transmission. If there's a leak, let him know where and how much is leaking. Time for a rebuild?

When your transmission gets tired enough, you'll have to have it rebuilt. It's true. For some makes and models of car, it's true a little too often, but that's neither here nor there. The important thing is checking any other possible causes to your problem before you take the transmission apart, which is very expensive. If you haven't replaced your filter yet, do it! This fixes a nice percentage of transmission problems. If your filter is good, and nothing simple is out of adjustment, be prepared to drop some serious dough on the rebuild. The good news is that most shops warrantee a transmission rebuild for a nice amount of time. A small consolation as your handing over the credit card, but at least you know that it will get fixed and stay fixed.

, Bank 2 is generally the side of the engine that doesn't have cylinder #1.

Note: This DTC is very similar to P0171, and in fact your vehicle may show both codes at the same time.

--------------------------------------------------- P0171 OBD-II Trouble Code

Note: This DTC is very similar to P0174, and in fact your vehicle may show both codes at the same time.

------------------------------------------ P1131 OBD Trouble Code= Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1 =

------------------------------------------ P1151 OBD Trouble CodeNOTICE: The information contained on this site is presented for information only. OBD-Codes.com is not responsible for any actions you take on any vehicles. If you have any doubt as to repairs on your vehicle, please contact a qualified technician.

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Oxygen Sensor

If you look inside the wheel wells behind the fender liner, right about where the frame is one O2 sensor, the other is underneath the truck about half way back in relation to the transmission. If you see where the exhaust joints together, you went about 6" too far.

When you start looking at the O2 sensors, they are normally numbered something like "Bank 1 Sensor 1" Bank 1 is on the passenger side; Bank 2 is on the driver's side. Sensor 1 is the upstream sensor (near the frame, between the block and the cat) and Sensor 2 is near the Y-pipe (downstream of the cat).

Normally it is the upstream sensors (sensor 1) that go first. They see the harshest conditions.

You will need;

Oxygen Sensor Socket

Anti-Seized

Penetrating Oil

Sometimes it will take 15 minutes or take a few hours it depends on your luck…

Okay, here's something else to consider for an aging F150, maybe other Ford products too? The AIRB or AIR BYPASS RELAY (SOLINOID) ages as does its counterpart the Diverter Relay. They are the same part and are hard to find let alone diagnose. The ERG relay is right next to both of these, at least in a 1996 PU.

SO, here was my problem: I could not get the diverter valve and the bypass air valves to coordinate properly. The bypass has to "know" to open and close in a rhythm like a heart beating. On my F150 the two valves are one part together where the air pump connects as well as the feed to the exhaust manifold.

If the diverter is not functioning, it'll cause a P0411. It may get a P0171 with it for a 6 cylinder. If you put pure vacuum on the diverter (both valves) then the darned P0171/174 combo will come up and the MIL is right back. The engine will run with a pure vacuum on both valves but may stall at idle. Note: EGR should have no vacuum going to it at idle. If it does, start there as you are basically chasing a vacuum problem, unless you have many other codes. Check or replace the DPFE sensor that operates the EGR, if you have one and you should. Just find it.

After doing everything in sight I finally touched on the idea of tying the EGR and the vacuum line to the diverter valve together using a Y connector. It worked. Not only did the P0411 go away but also the P0171 and the pesky come-and-go P0174. These say too lean a mixture. Bank 1 means cyl 1-3 in a straight 6.

The books say all sorts of things about the 171/174 situation including replacing the valve cover gasket. Guess what? Mine was loose so I merely tightened it. It's difficult to reach the rear bolts with the engine assembled. Do what you can reach, gently! Make sure everything is tight and as close to torque as possible. Check the PCV valve and its hose.

One other thing: To help ensure that the engine would pass smog tests, I put 92 octane gas in it for a few days. That's just a small insurance policy. My MIL has stayed off. I'm not able to further diagnose why the darn AIRB relay is not totally working. The problem is that another vac line leaves it and I was concerned about touching a relay or line I could not get a part number for. Those cheap plastic vac lines don't age very well. It was NOT a fuel pressure problem.

Heaven only knows what I'd have been charged at a repair shop? I figure they'd have said "it's the head" or worse. That'd been $1400 in CA priced labor right there! Keep at your fix. You can do it! I did. It just took two weeks to experiment with the engine. Spray silicone on all exposed rubber elbows from time to time. That'll keep them from cracking. My F150 has 279k on it. So far, I've not had to mess with the fuel pump. Those fuel filters last almost forever too.

{| |+ Special Service Tool(s) |- | Cam Positioning Tool

T91P-6256-A Cam Positioning Tool Adapters

T92P-6256-A Camshaft Holding Tool

T96T-6256-B Camshaft Positioning Tool

T96T-6256-AR Removal # Remove the engine front cover; refer to the procedure in this section. # Remove the (A) crankshaft sensor ring from the (B)crankshaft (6303).

# On WEP engines, use the (A) Camshaft Positioning Tool to position the (B) camshaft.

# on REP engines, rotate the crankshaft until both camshaft keyways are 90° from the cam cover surface. On REP and WEP engines, make sure the copper links line up with the dots on the camshaft sprockets.

# On REP equipped engines, install the (A) Cam Positioning Tool and the Camshaft Positioning Tool Adapters on the (B) camshaft.

# On WEP engines, install the (A) Camshaft Holding Tool on the (B) camshaft.

# Remove the (A) LH timing chain tensioner bolts and the (B) LH timing chain tensioner.

# Remove the (A) RH timing chain tensioner bolts and the (B) RH timing chain tensioner.

# Remove the LH and RH timing chain tensioner guides from the dowel pins.

# CAUTION: At no time, when the timing chains are removed and the cylinder heads are installed may the crankshaft or camshaft be rotated. Severe piston and valve damage will occur. Remove the RH and LH timing chains and crankshaft sprockets. ## Lift RH timing chain off of the camshaft sprocket and slide the timing chain and crankshaft sprocket off of the crankshaft. ## Lift the LH timing chain off the camshaft sprocket and slide the timing chain and the crankshaft sprocket off of the crankshaft.

# On REP engines, remove the chain guides. ## Remove the LH timing chain guide bolts. ## Remove the LH timing chain guide. ## Remove the RH timing chain guide bolts. ## Remove the RH timing chain guide.

# On WEP engines, remove the chain guides. ## Remove the LH timing chain guide bolts. ## Remove the LH timing chain guide. ## Remove the RH timing chain guide bolts. ## Remove the RH timing chain guide.

Installation CAUTION: Timing chain procedures must be followed exactly or damage to valves and pistons will result. # Compress the timing chain tensioners (6L266). ## Release the lock assembly on the timing chain tensioners. ## Compress the timing chain tensioners.

# Install the retaining pins.

# Check the following components for part number orientation.

! valign="bottom" | Item ! valign="bottom" | Part Number ! valign="bottom" | Description | 1 6268 Timing Chain/Belt (RH) 2 - RH Timing Chain Guide (WEP) 3 6L253 Timing Chain Tensioner Arm (LH) 4 6L266 Timing Chain Tensioner (LH) 5 6268 Timing Chain/Belt (LH) 6 - LH Timing Chain Guide (WEP) 7 6K297 Timing Chain Guide, (REP) RH 8 6L253 Timing Chain Tensioner Arm (RH) 9 6L266 Timing Chain Tensioner (RH) 10 6K297 Timing Chain Guide, (REP) RH

# On REP engines, install the timing chain guides. ## Position LH timing chain guide. ## Install and torque the LH timing chain guide bolts. ## Position the RH timing chain guide. ## Install and torque the RH timing chain guide bolts.

# On WEP engines, install the timing chain guides. ## Position the LH timing chain guide. ## Install and torque the LH timing chain guide bolts. ## Position the RH timing chain guide. ## Install and torque the RH timing chain guide bolts.

# Install the timing chain/belts (6268) and crankshaft sprockets (6306). ## Slide the (A)crankshaft sprocket onto the (B) crankshaft, aligning the copper link on the timing chain/belt with the dot on the crankshaft sprocket. ## Position thetiming chain/belt over the camshaft sprocket, aligning the copper link with the dot on the camshaft sprocket.

# Make sure that the (A) copper marks on the timing chain/belts are lined up with the corresponding dots on the crankshaft and camshaft sprockets.

# Make sure that the (A) camshaft sprocket keyway is 90° from the (B) cam cover mounting surface.

# Make sure that the (A) RH timing chain sprocket is on the front of the (B) LH timing chain sprocket with the hubs facing each other.

# Position the LH and RH timing chain tensioner guides on the dowel pins.

# Position the RH timing chain tensioner and install the timing chain tensioner bolts.

# Position the LH timing chain tensioner and install the timing chain tensioner bolts.

# Remove both the RH and LH retaining pins from the timing chain tensioners.

# On REP engines, remove (A) Cam Positioning Tool and the Camshaft Positioning Tool Adapters on the (B) camshaft (6250).

# On WEP engines, remove the (A) Camshaft Holding Tool from the (B) camshaft.

# On WEP engines, remove the (A) camshaft positioning tool from the (B) camshaft.

# Install the (A) crankshaft sensor ring on the (B) crankshaft.

# Install the engine front cover; refer to the procedure in this section. |}