I just completed a cam install and i'm getting the PCM 1515 code and the 1278 code due to it, putting me in reduced power mode. Is the 1515 code just due to the car adjusting to the cam, or is it something else? Resetting the code does nothing - it comes back immediately. Please help, i'm driving my parents truck until i get it fixed!

 

DTC P1515 Control Module Throttle Actuator Position Performance

Circuit Description
The commanded throttle position (based on accelerator pedal position and possibly other limiting factors) is compared to the Actual throttle position. The 2 values should be within a calibrated range of each other. Both the PCM and the TAC module redundantly monitor the Commanded and Actual throttle position. This DTC sets if the PCM detects the problem.

Conditions for Setting the DTC
DTCs P0601, P0602, P0606, P1516, P1517, P1518, P1624 not set.
DTCs P1120, P1220 and P1221 not set at the same time or DTCs P1120 and P1220 not set at the same time.
The ignition switch is in the crank or run position.
The ignition voltage is greater than 8.5 volts.
Not in battery saver mode.
The PCM detects that the commanded and actual throttle positions are not within a calibrated range of each other.
All above conditions met for less than 1 second.
Action Taken When the DTC Sets
The PCM will illuminate the Malfunction Indicator Light (MIL) when this diagnostic runs and fails.
The Reduced Engine Power message displays on the drivers information center.
The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or Failure Records.
If no other TAC System DTCs are set, the TAC System will operate in Reduced Engine Power mode. If certain TAC System DTCs are set at the same time, the TAC System either defaults to a more tightly restricted mode of operation if the TAC determines that limited safe operation is possible, or the TAC commands the engine to shut down.
Conditions for Clearing the MIL/DTC
The PCM turns the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
The PCM battery voltage is interrupted.

Important
The clear DTC info function may have to be performed twice in order to clear a Throttle Actuator Control System DTC.

Clear the MIL/DTC information using a scan tool.

Diagnostic Aids
If you do not find any trouble, check for mechanical problems or binding that may be temperature related. Components may not move freely in extreme heat or cold due to the presence of contaminants or ice formation.
The following may cause an intermittent:
Poor connections. Check for adequate terminal tension. Refer to Body and Accessories/Wiring Systems for proper procedure.
Corrosion
Mis-routed harness
Rubbed through wire insulation
Broken wire inside the insulation
Inspect the TAC module connectors for signs of water intrusion. When this occurs, multiple DTCs should be set and no circuit or component problems can be located.
For an intermittent condition refer to Symptoms .
If a repair is completed and the DTC was cleared using a scan tool on the same ignition cycle, the default action will not clear until an ignition cycle has occurred.
When the TAC module detects a problem within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing captured DTC info.

 

thanks Patches! I'm praying it's just a loose wire...