Battery disconnected, control module reset or throttle body or module replaced without a throttle relearn being performed; Throttle body dirty with carbon deposits, so the plate does not return to or settle at the closed position properly; Faulty or worn throttle body or internal TP sensor giving erratic or out-of-range readings; Wiring or connector fault on the throttle body circuits, such as corrosion, chafing or poor terminal tension; Low battery voltage or poor charging system stopping the learn from completing; Intake air leak or idle air control issues upsetting the learn conditions (depends on engine and model); Engine control module fault or outdated software.

P1526

TP Sensor Learn Not Complete.

Buick
Powertrain
Manufacturer code
Medium severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
5: AreaVehicle speed, idle control and auxiliary inputs
26: FaultThe specific fault in that area

What it means

P1526 on a Buick means the engine control module has not completed the throttle position (TP) sensor learn procedure. The module needs to learn the closed-throttle position of the electronic throttle body, and either the learn has not been run after a reset or repair, or it started and could not finish. Until it completes, throttle control may be restricted.

Symptoms

Malfunction indicator lamp on, and possibly a reduced engine power or throttle warning
Unstable, high or low idle speed
Poor or delayed throttle response
Engine stalling or a tendency to stall when coming to a stop
Restricted engine power or limited throttle opening
Other throttle-related codes stored alongside

Possible causes

Battery disconnected, control module reset or throttle body or module replaced without a throttle relearn being performedlikely
Throttle body dirty with carbon deposits, so the plate does not return to or settle at the closed position properlylikely
Faulty or worn throttle body or internal TP sensor giving erratic or out-of-range readingspossible
Wiring or connector fault on the throttle body circuits, such as corrosion, chafing or poor terminal tensionpossible
Low battery voltage or poor charging system stopping the learn from completingpossible
Intake air leak or idle air control issues upsetting the learn conditions (depends on engine and model)rare
Engine control module fault or outdated softwarerare

How to diagnose

Read all stored and pending codes and freeze frame data, and note any other throttle, TP sensor or voltage codes, as these should be dealt with first
Check battery condition and charging voltage, as the learn needs stable voltage
Ask whether the battery was disconnected or the throttle body, module or intake parts were recently changed
Inspect the throttle body wiring and connector for damage, corrosion, loose pins or water ingress
Inspect the throttle body bore and plate for carbon build-up, and check that the plate moves freely and returns smoothly (follow the manufacturer's method for that engine)
Check for intake air leaks, split ducting and vacuum leaks that could disturb idle
With a scan tool, view the TP sensor readings at closed throttle and while moving the pedal, checking they are smooth, consistent and within specification
Carry out the manufacturer's throttle relearn procedure for that model and engine, then clear the code and retest to confirm it does not return

How to fix

Perform the correct throttle position sensor or throttle body relearn procedure for the specific model and engine, with the engine at the required conditions
Clean the throttle body using the method approved for that engine, then relearn
Repair or replace damaged wiring, terminals or connectors on the throttle circuit
Replace the throttle body if the sensor readings are erratic or the plate sticks, then carry out the relearn
Repair the battery or charging fault so the learn can finish
Update the control module software only if the manufacturer identifies a calibration issue for that vehicle

Can I keep driving?

Medium severity

The car can usually be driven short distances, but the engine may idle poorly, stall or have limited power, which can be unsafe in traffic. Have it dealt with soon, and avoid driving it if it stalls or loses power.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.