P2163 indicates the Engine Control Module (ECM) has detected that the Throttle Pedal Position Sensor (TPS) is not reaching its expected maximum voltage signal when the accelerator pedal is pressed to the wide-open-throttle (WOT) position. The sensor fails to achieve its calibrated maximum stop value, triggering a fault and potentially activating reduced engine power (limp) mode.
The pedal-mounted potentiometer is the most common cause — internal wear, contamination, or electronic failure prevents the sensor from reaching its maximum voltage output at full pedal travel.
Damaged, corroded, chafed, or loose wiring and connectors between the sensor and ECM can interrupt proper signal transmission, causing the ECM to see an artificially low maximum voltage.
The accelerator pedal mechanism itself may be binding, worn, or contaminated, preventing full travel and thus preventing the sensor from reaching its maximum signal point.
Carbon buildup or mechanical problems in the throttle body can affect the overall throttle response, though this more commonly sets other TPS codes; it may contribute to P2163 in some vehicles.
In rare cases, outdated or corrupted ECM software/firmware may incorrectly interpret sensor signals, though this is uncommon and usually affects multiple sensors.
A failed input circuit within the ECM is possible but unlikely — this should only be considered after all other causes are definitively ruled out.
Yes, most vehicles will enter reduced power (limp) mode when this code sets, severely limiting acceleration and top speed to prevent potential damage.
Driving is possible but strongly discouraged — limp mode significantly reduces performance and may leave you stranded if conditions demand full power (such as merging onto highways). Have it diagnosed promptly.
Almost never. The ECM is very rarely the cause of this code. In the vast majority of cases the fault is in the throttle pedal sensor, its wiring, or the pedal mechanism itself. Technicians sometimes suggest ECM replacement unnecessarily — verify all other causes first.
Unlikely. While throttle body carbon buildup can cause drivability issues, P2163 specifically indicates a pedal position sensor problem, not a throttle body issue. Cleaning may help if there are related hesitation symptoms, but it won't address the core maximum-stop performance fault.