Wrench Light 2008 F150

Good morning. I have a 2008 f150 5.4 TRITON v8 xlt. For the past 7 months, my truck randomly produces an error code. P2135 Thottle/Pedal Position Sensor/ Swith A/B Voltage Correlation. The wrench lite comes on and the truck goes into limp mode. I can usually clear by a couple of methods: turning off the engine, disconnecting the battery, clearing the code, or clearing the computer (PCM). This is usually a quick fix, but the problem keeps coming back.

I brought it to a mechanic. He replaced the throttle body. A week later, the problem came back and I brought it back in. He replaced the throttle body again, thinking it maybe a defective part. Ran some diagnostics, and eliminated the pedal sensor, the throttle body. Determined that there were 2 bad coils, started by replacing spark plugs.

Problem still persisted. I changed out all 8 coils, put a new battery in(probably not related), unplugged the throttle sensor, the pedal sensor, the coil wires and the three cables going to the PCM. Waited a couple of minutes and plugged everything back in. Next, I cleared the PCM by disconnecting the negative cable from the battery and connected with an alligator clip to the positive pole on the battery for 15 minutes. Reconnected the battery, turned off all accessories, turned key on and let ignition run thru its beeps and then started the truck, let the truck idle for 15 minutes to relearn everything. This was effective for four months. Now the problem is back again and driving me crazy.

As far as I can tell, the issue began after the serpentine belt was replaced. Last weekend, I had to replace the tensioner pulley assembly. I was hoping I had found the issue.

The problem persisted after 4 days.

The error code is thrown in various situations, as I have tried to monitor what is going on when it happens. 1. truck is idling and heater is on
2. after running truck on highway for at least 10 minutes and get caught in traffic, truck idles at 1800 RPM’s
3. running A/C unit
4. traveling at 65–75mph on highway, no idling, or after idling in traffic

I have heard something about the air intake causing this problem, but have not researched yet…

I have guessed that it is some type of wiring issue, but not sure where to look.

Please help!!!

Instead of throwing parts and money at it, find a good independant mechanic… I am sure he will find the problem in no time.

1 Like

Just found the real issue: The complaint alleges that between 2004 and 2008, Ford manufactured, assembled and marketed a host of products containing latent defects.

Since calendar year 2005 and up until 2012, the Defendant has been aware of consumer complaints regarding a Class of Vehicles (equipped with the 5.4L engine) identified and described more fully below. These complaints have been made directly to Defendant and/or submitted to the National Highway Traffic Safety Administration (“NHTSA”), Office of Defect Investigation.

This Class of Vehicles suffered from defects in design and/or manufacture, which has led to the following performance and safety issues: acceleration hesitation, loss of revolutions per minute (“RPM”), stalling, loss of power (including loss of power at high rates of speed), sudden and intermittent deceleration and other similar and potentially life-threatening malfunctions (hereinafter referred to as “Engine Problems”).

The Engine Problems are the result of defects in the following vehicle systems and components: the Powertrain Control Module (PCM), the Transmission Control Module (TCM), the Electronic Throttle Control (ETC) and/or the Throttle Body Assembly.

In August 2008, as proof of knowledge of the Engine Problems, Defendant issued a Technical Service Bulletin (“TSB”) to notify its dealership network (and others in the service and repair industry) of the procedures necessary to rectify the defects.

Although Defendant recognized in 2008 that many of its vehicles contained Engine Problems, it actively concealed from the public, and the owners of this Class of Vehicles, the need to perform certain services and/or repairs to remedy these defective and potentially life threatening conditions.

Defendant chose not to inform its dealership network, or others who received the TSB, that the aforementioned Engine Problems were under Express Warranty, which the defendant was under a contractual duty to service and/or repair. Concealment of these Engine Problems was orchestrated to minimize and/or avoid the defendant’s contractual responsibility to the Plaintiff class of owners.

The applicable express warranty related to the Class of Vehicles and Engine Problems at issue is 8-years or 80,000 miles, whichever occurs first. The Engine Problems in this case did not arise in the named Plaintiffs’ vehicles until 2012, at which time the breach of warranty was discovered and realized.

Class: “Current owners of all 2004 through 2008 Ford passenger car and light truck vehicles sold in the United States and equipped with a 5.4 L engine and which include the original Powertrain Control Module (PC’M), the Transmission Control Module (TCM), the Electronic Throttle Control (ETC) and/or the Throttle Body Assembly. The class of vehicles is limited to those delivered within 8 years and having less than 80, 000 miles.”

You have a 10 year old truck that developed a problem. It’s not unusual and the error code is helping to point to the issue. You report the symptoms appear randomly. Exactly how was the pedal position sensor tested and ruled out?

My mechanic did the diagnostic check on the pedal sensor, not sure exactly. You can’t just buy the sensor anymore, you have to buy the whole pedal assembly.

If you scroll up, you will see that there is a much bigger issue with 5.4 triton engine.

I don’t believe your problem is related to those issues. It would be unlikely any mechanic would invest the amount of time required to definitively diagnose your random issue with the pedal sensor. It could test fine for hundreds of times before it has a flaky output. The engine computer will eventually see it happen and set the code.

I might be inclined to buy a used one to see if it fixes the problem. Junkyard part will be a fraction of cost for new…

How is not related? I have experienced everything in that class action…The truck has stalled out on the highway, gone into limp mode numerous times, each time I clear the PCM the problem goes away. It’s not the pedal sensor. This engine has impacted thousands and thousands of owners, you are telling me my truck is unique? No way…You have not lived it…

How many miles on your truck?

There are many many reasons this symptom could result. You have a very specific error code.

THAT, is a guess and based on questionable analysis at this point.

I don’t need to LIVE your particular problem to understand it. I’ve had plenty of vehicle issues I have fixed myself. I don’t spend time on them as if it was life changing event. I fix it and move on. You haven’t even tried to address the most relevant suspect yet… good luck, I’m out…