Truck: 2005 Tacoma DC LB 4.0L with Auto, 70,000 miles, dual Optima Blue Tops using National Luna products, no other major engine/electrical modifications that should relate
Symptoms: Truck has little/no throttle response and hesitation upon acceleration. When symptoms occur the truck feels like it has no power. Biggest symptom though is the little to no throttle response. I can have the throttle at WOT and get no response. Symptoms are sporadic and seem to occur when the truck is cold. Once the truck warms up and/or been cycled on off a couple times the problem goes away but the CEL remains on for a few more cycles.
CEL is on and codes pulled were a P2121 and P2127
Troubleshooting: Took the truck in to the Toyota Dealership and had them run codes and troubleshoot. P2121 is Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance. The truck had not had the 90L Pedal Assembly recall completed yet so that was the first step. New pedal assembly and Code 2127 remains. P2127 is Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input. After testing it was found that the voltage was low at throttle position #2. The connectors were removed to check and clean contacts. That did not resolve the issue.
At this point, the dealership recommends replacement of the ECM wiring harness and/or Replacement of the ECM. They say that the only three components to the system are the ECM, Wire Harness, and Throttle Pedal Assembly. Iím still not sold that itís the ECM or Wiring harness. Both those are pretty big ticket items and Iíd hate to replace all that and still have the issue persist. Iím looking for input, ideas, and different approaches from other Toyota owners. Thanks.