P1526
Circuit Description
The Throttle Position (TP) sensor on the PFI engine is self adjusting. When the ignition is turned OFF, the PCM executes a TP sensor learning routine. If the same correction factor occurs on two consecutive key OFF cycles, the TP sensor is then corrected to 0 degrees using the correction factor learned. This diagnostic test checks to see if initial TP sensor Learn values have been stored in the PCM. If these values have not been stored, DTC P1526 is set. Performing the TP Sensor Learn Procedure on the next page will cause DTC P1526 to become history.
Conditions for Setting the DTC
Test Conditions
Test continuously.
Failure Condition
No TP sensor learn value is stored.
Action Taken When the DTC Sets
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The PCM will command a message to be displayed.
^ The PCM may record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records.
Conditions for Clearing the Message/DTC
^ The PCM will turn the message OFF after one run and pass of the diagnostic test.
^ A History DTC will clear after forty consecutive warm-up cycles with no failures of any nonemission related diagnostic test.
^ A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
^ PCM battery voltage is interrupted.
^ Using a Scan tool.
Diagnostic Aids
Make sure nothing is touching or obstructing the accelerator or brake pedals during the TP learn procedure because this will prevent the PCM from performing the learn routine.
If DTC P1526 does not pass following the completion of the TP Sensor Learn Procedure, this may be due to incorrect or erratic signals from the TP Sensor.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
3. The accelerator must not be moved or the procedure must be redone.