Yesterday I took my F150 to a local Ford dealer for an oil change/tire rotation @6,300 miles. I mentioned to the service adviser that my engine symbol light came on some months ago and that my automatic transmission seemed to hunt for the correct gear at speeds around 55MPH, a speed I frequently drive at. I also mentioned that in Feb of this year I had parked the truck in a secured garage for two months and when I began using the truck discovered a dead mouse on the front floor mat and that the odor was significant. I had added the fuel saver Stabil when the truck was parked and temporarily stored. I also charged the battery in the truck before I started it. I cannot be certain but sometime soon after driving the truck I noticed the engine symbol was lit in the dash. My manual suggested it could be due to fuel or odor; it did not indicate any sensor issue other than the possible cause. In time the odor issue was resolved and while I use the truck infrequently I went thru several tanks of fuel.
I had thoroughly inspected the truck for a rodent problem and specifically the engine compartment. I live in a rural ranch area and field mice are common. There were no visible signs of droppings or rodents in the truck. Other than the transmission hunting issue the truck ran as expected.
The service tech opened the hood and looked for clues and we did observe three very small droppings on top of the battery. These had to have been deposited well after I noticed the engine light on. The tech said that I would be responsible for a diagnosis fee of about $130 since the cause of the light was a pack rat. I'm nearly 70 years old, I know the difference between a rat dropping, a mouse dropping, and frankly the lizard droppings are nearly identical to a rodents droppings. I objected to the fee since there was not any other evidence to suggest a rodent had affected the wiring, left droppings, or any other clues. I advised the tech that I would appeal to Ford and my credit card provider a fee for diagnosis since other than the small droppings on top the battery I did not feel a test to determine the cause of the light was 'not' a warranty issue. I left the truck for three hours and returned. The tech opened the hood and pulled the pencil sized wire from behind the engine out and it was severed; a clean slice at about 60 degrees. He said the cost of repair would be in the $600-650 range and that I could contact my insurance provider. I have a very high deductible, more than the estimate and I told him that. I declined to have the work done and asked if the truck was ready for me. He said yes and I went to my the parking lot to tell my wife she could go home and I'd follow ASAP. While talking with my wife the tech came to us and said the truck was not ready since they failed to do the oil change and tire rotation. He said it would be 30 minutes so I sent my wife home and went to the waiting area. After about 20 minutes he approached me in the waiting area and said he could work with me on the estimate. He asked what I felt was 'fair'. I repeated for perhaps the 3rd time that I objected to an diagnosis fee, that the evidence of a severed wire was not sufficient to conclude 'pack rat' damage and that I felt an objective look by someone else was the direction I was headed. I then asked what he thought was 'fair' and he said about $300. I told him I appreciated the offer and might return after I pursued the issue elsewhere. He returned 15 minutes later and indicated the truck was ready and to check with the cashier to get my keys. I did so; the cashier reviewed the service pages, said the test was a warranty issue, the oil change was free (it comes with new trucks from this dealership for 'life'.) She had me sign the form, gave me the keys and I proceeded to my truck. Upon leaving the tech hollered out to me and I stopped the truck and opened the door; he said there had been a mistake, I hadn't paid for the inspection. I told him I was not going to pay for it, that I had objected to it from the beginning and that I was leaving.
I asked him what they found with the transmission issue and he stated that they could not perform that test until the knock sensor was replaced. He then asked for a moment, went into the cashiers office and returned and said I could no longer receive service at his dealership. I asked why he felt he had the authority to decline service and he said the message came from the top.
We have in our small community a retired senior auto mechanic and I asked him about the effects of a disconnected knock sensor and his opinion was that it would not have any effect on an automatic transmission.
The engine light is no longer on, and the severed wire is as is.
My hunch is that the sensor wire may have damaged during assembly, or some sharp metal may have severed it. Rodents generally leave other evidence, chewed material, etc.
Essentially my question is: is the transmission affected by a knock sensor and also if the severed wire caused the engine light why is it off now? Windy story; sorry. Thanks CJones