Gossamer

Ford F-150 XL FX4
5.4L, S-cab, 8ft bed (freaking HUGE)
220k miles

This truck is new to me, so I am tracking down some issues left-over from the previous owner(s). History I know of, is it started as a "fleet truck" then sold to a paving contractor and used off-road for approx 3yr to tow equipment on-site.

I have dash lights that come on periodically. Some I believe I know whats up, others seem random. Current codes that re-occur on the scanner: P0420 & P0622


CHECK ENGINE LIGHT
P0420 - I see there are some strange readings on one of the O2 sensors on the passenger side (IIRC), so that just needs to be replaced I am assuming. The reading for the second O2 on either side is supposed to stay around 0.5v from what I have read, but mine jumps all over the place for that 1 sensor.

CHECK BATTERY LIGHT
P0622 -Generator Field Terminal Circuit fault (or something like that). The reading on my code scanner shows the "VPWR" to be around 13v while running at idle. So is the sensor that sensitive that it will turn the dash light on for these readings?

CHECK BRAKES LIGHT
Brake / E-brake dash light: This ALWAYS comes on when I press the e-brake, but also comes on just driving down the road. Is there a sensor on the brake pedal that goes bad? This would be my first guess.


Thanks for the help in advance.

techrep

iTrader: (1)

Check batt light PO622 ...alt is going bad...should be putting out 14+vdc.. the voltage reg is bad.. replace alt with a motorcraft re-man...trust me on this.


Check brakes light.. check brake fluid level..check that the parking brake is releasing all the way...check the back brakes the e-barke pads ...the release lever gets corroded and stops working.


PO420 DTC ... I would replace that 02 sensor or at least pull it out clean it .. check the wires to it also.

Gossamer

I did check the brake fluid in the truck and the level was fine, but I am not used to seeing these fluids yet. Many of them look different than the fluids in my old Ranger. The E-brake also "appears" to be fully released.

I took it to the shop today where I have been thus far less than impressed with the level of customer service....... Separate topic.

It seemed like it was due for an A/C check-up and it is HOT here too often so I wanted to see what they would say about any of these issues.

JimWills

Bad Alternator / Battery voltage can cause all sorts of weird stuff, fix that and see whats left.

Gossamer

Long story short: The brakes made themselves the top priority as they went downhill fast. Whoever did the replacement of the fronts didn't put the "wishbone" return springs on the driver's side. Needless to say this ended in metal on metal.

Rotors replaced (OEM Motorcraft)
Calipers replaced (OEM Motorcraft)
Pads replaced with return springs on the fronts. (OEM Motorcraft)
Guides replaced & greased all 4 corners. (OEM Motorcraft)
E-brake adjusted not replaced
Brake fluid flushed out. (Valvoline ABS DOT fluid)
Lines bled in order RR, LR, RF, LF

I had hopes the Brake light on the dash would stop coming on, but it still does from time to time.

Assumption 1: The sensor that triggers the light is functional, and there is a problem somewhere.
Question: What triggers the sensor?

Assumption 2: The sensor that triggers the light is failing.
Question: What sensor is this & where?



On the other issues, O2 sensor purchased, not replaced yet, same for the alternator. I will get to those as soon as I can.