For 1990-2009 cars

# RESETTING LEARNED IDLE THROTTLE ANGLE OFFSET

#### SUBJECT: PROCEDURE FOR RELEARNING TPS AND IDLE THROTTLE ANGLE OFFSETS AFTER A BATTERY DISCONNECT AND/OR CODE E52/E052 ON 1990-1992 DEVILLES, FLEETWOODS, ELDORADOS, AND SEVILLES AND 1987-1992 ALLANTES EQUIPPED WITH 4.1/4.5/4.9 PFI ENGINE

This bulletin has been revised to include new procedures and add a model year. This bulletin replaces DSIB 91-I-11

TP sensor learn and idle learn are an integral part of 1990-1992 DeVilles, Fleetwoods, Eldorados, and Sevilles and 1987-1992 Allantes PCM PROM. These "learn" routines allow the vehicle to compensate for TP sensor adjustment and the loss of air flow due to throttle body deposits. TP sensor and idle learn procedures are to be done when any of the following occur:

o Battery disconnected for service

o Battery replacement

o Code P-052/E52

o Throttle body replacement

o TP sensor replacement

Vehicle Relearn Procedure:

1. Inspect the throttle linkage for any signs of binding or improper c/c linkage adjustment. Ensure that the accelerator pedal is free and clear.

2. Ensure that the min air rpm is set per the following table:

Model Year Min Air RPM ----- ---- ----------- V 1987-1988 500 V 1989-1990 550 V 1991-1992 475 ( 500 miles on odom V 1991-1992 550 ) 500 miles on odom C/E/K 90-92 500 ( 500 miles on odom C/E/K 90-92 525 ) 500 miles on odom

3. Make sure that the outside air temperature reading is at least 50F.

4. Perform TP sensor learn:

#### NOTE: Do not touch the accelerator pedal or steering wheel during the TP sensor learn procedure.

o Ignition on (engine not running)

o Enter diagnostics

o Turn ignition off

o Wait a minimum of 20 seconds

o Turn ignition on (engine not running)

o Re-enter diagnostics

o Turn ignition off

o Wait a minimum of 20 seconds

o Turn ignition on (engine not running)

o Re-enter diagnostics

o Turn ignition off

o Wait a minimum of 20 seconds

5. Bring the vehicle up to operating temp.

o On a 1990 C/E/K vehicle, run the engine continuously for 18 minutes.

o On a 1991-1992 C/E/K vehicle, run the engine continuously for 13 minutes.

o On a 1987-1992 Allante, run the engine continuously for 18 minutes.

6. Idle Learn:

o Place the transmission in drive with the brakes applied.

o Place the Electronic Climate Control in the "OFF"-Position. Allow the vehicle to remain at idle for at least one minute.

o Place the Electronic Climate Control in the "AUTO" position. Verify that A/C compressor engagement occurs. Allow the vehicle to remain at idle for at least one minute.

o Place the transmission in park and turn the ignition off.

#### IMPORTANT: Because of the load differences on the engine with A/C on versus A/C off, learning must occur under both conditions.

A time of . 1 hour is added to each procedure that requires the battery to be disconnected. The Labor Time Guide reflects this change.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.