'04 Taco; Flashing CEL comes on and goes off ~ 2004 Toyota Tacoma

[eric weber]

Hi all,
We have an '04 Tacoma SR5 with 61K miles that had a flashing CEL. Initially, the codes were P0302 and P0305, but the diagnostics showed that all of the engine parameters were good while driving, except for an infrequent misfire. We ended up changing out the #5 coil pack and all the coil wires, new plugs, replaced the fuel filter, had the injectors cleaned and they checked the ECM.

The CEL stayed off for a few days, came on (flashing) and shut off 10 minutes later. We took it back to Toyota, they kept the truck for two days and could not find anything wrong after running the diagnostics and driving the truck under load a few times. In addition, no codes were stored. Our son got on the road and the CEL started flashing again, it shut off and stayed off for a 450 mile trip (the truck ran perfect the whole trip).

A couple days after he arrived at his destination, it started flashing again, and the truck still runs fine. We are at a total loss for what is going on. Could this be an electrical issue with the CEL?

 

[tbplus10]

04 would mean it has the 3.4, this engine even when new had an issue with corrosion on the grounds connections and wires for the coil packs.
Start by checking the grounds and wires for the affected cylinder.

 

[toyotafan]

Hi all,
We have an '04 Tacoma SR5 with 61K miles that had a flashing CEL. Initially, the codes were P0302 and P0305, but the diagnostics showed that all of the engine parameters were good while driving, except for an infrequent misfire. We ended up changing out the #5 coil pack and all the coil wires, new plugs, replaced the fuel filter, had the injectors cleaned and they checked the ECM.

The CEL stayed off for a few days, came on (flashing) and shut off 10 minutes later. We took it back to Toyota, they kept the truck for two days and could not find anything wrong after running the diagnostics and driving the truck under load a few times. In addition, no codes were stored. Our son got on the road and the CEL started flashing again, it shut off and stayed off for a 450 mile trip (the truck ran perfect the whole trip).

A couple days after he arrived at his destination, it started flashing again, and the truck still runs fine. We are at a total loss for what is going on. Could this be an electrical issue with the CEL?

@eric weber did you find out anything else about this? Updates?