Fault in the throttle position sensor or its signal output; Damaged, chafed or shorted wiring in the TPS signal or PWM circuit between the engine and transmission modules; Corroded, loose or spread terminals at the sensor, module or harness connectors; Poor reference voltage or ground supply to the sensor; Dirty or faulty throttle body affecting the reading; Faulty engine or transmission control module, or outdated software calibration where the manufacturer has issued an update.

P1892

Throttle Position Sensor PWM Signal High.

GMC
Powertrain
Manufacturer code
Medium severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
8: AreaTransmission
92: FaultThe specific fault in that area

What it means

P1892 on a GMC means the control module has seen the throttle position sensor PWM (pulse width modulated) signal sitting higher than expected, outside the range it should produce. In GM applications this signal is typically shared between the engine control module and the transmission control module, so the fault can be logged by either. Exact signal arrangement and strategy vary by model, engine and transmission.

Symptoms

Check engine light or service vehicle soon message on
Harsh, delayed or erratic gear changes
Transmission stuck in one gear or in a limp-home mode
Poor or inconsistent throttle response
Unstable idle or hesitation on pull-away
Cruise control not working

Possible causes

Fault in the throttle position sensor or its signal outputlikely
Damaged, chafed or shorted wiring in the TPS signal or PWM circuit between the engine and transmission moduleslikely
Corroded, loose or spread terminals at the sensor, module or harness connectorslikely
Poor reference voltage or ground supply to the sensorpossible
Dirty or faulty throttle body affecting the readingpossible
Faulty engine or transmission control module, or outdated software calibration where the manufacturer has issued an updaterare

How to diagnose

Read all stored and pending codes and record the freeze frame data, noting whether engine or transmission codes appear alongside P1892
Visually inspect the throttle body, sensor, harness and connectors for damage, water ingress, corrosion and chafing
Using a scan tool, compare the live throttle position percentage with the pedal position from closed to wide open and look for jumps, dropouts or a value stuck high
Check the sensor reference voltage, ground and signal voltage against the manufacturer's specification for your model and engine
Check the PWM signal with an oscilloscope or suitable meter to confirm duty cycle and that it follows throttle movement
Perform a wiggle test on the harness and connectors while watching live data for glitches
Check the wiring for shorts to voltage or ground, and for resistance faults, between the sensor and each module
Check for relevant software updates or technical bulletins for the vehicle before condemning a control module

How to fix

Replace the throttle position sensor or throttle body assembly if the signal is proven faulty, then carry out any required relearn procedure
Repair or replace damaged wiring between the sensor and the control modules
Clean or replace corroded or loose connector terminals
Restore a correct reference voltage or ground supply by repairing the supply circuit
Clean the throttle body in line with the manufacturer's procedure if contamination is affecting operation
Update the control module software where a known fault exists, or replace a confirmed faulty module

Can I keep driving?

Medium severity

The car can usually be driven short distances, but erratic shifting or limp mode can make it unpredictable, and continued use may stress the transmission. Have it diagnosed soon, and avoid driving it if it is changing gear harshly or the throttle response is unreliable.

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