GM Service Manual Online
For 1990-2009 cars only

Object Number: 891484  Size: MF

Circuit Description

Limp-home is a reduced power condition the vehicle enters after certain faults. In this drive mode, throttle position is limited to 3.7% - 9.8%. This DTC will set if the TP should fall below 3.7% or open more than 9.8% while the vehicle is in limp-home mode. This code results in fuel cut-off and the engine will not start again.

DTC Parameters

DTC P1511 will set if TP is less than 3.7% or TP is greater than 9.8% when:

    • Vehicle speed is not present
    • Engine speed less than 250 rpm
    • ECT is between 5°C-100°C (41°F-212°F)
    • IAT greater than 5°C (41°F)
    • Battery voltage greater than 10 volts
    • Pedal position less than 15%

P1511 is a (type A) DTC.

Diagnostic Aids

Possible causes:

    • Weakened springs in throttle assembly
    • Throttle plate forced to extreme position by surge of air, carbon deposits
    • Circuit failure to throttle motor
    • Throttle position sensor not functioning properly (check for TP sensor DTCs)
    • Throttle body