P2299 – Brake Pedal Position / Accelerator Pedal Position Incompatible

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: General

Definition source: SAE J2012/J2012DA (industry standard)

P2299 indicates the powertrain control module has detected an incompatibility between the brake pedal position signal and the accelerator pedal position signal. In other words, the two inputs do not agree in a way the system considers plausible for safe operation. The exact enable conditions, thresholds, and how the vehicle reacts (such as limiting throttle) can vary by vehicle, so you should verify the specific criteria and pinouts in the applicable service information. Addressing this promptly is important because it can affect throttle response and overall drivability.

What Does P2299 Mean?

P2299 – Brake Pedal Position / Accelerator Pedal Position Incompatible means the control system sees a mismatch between the reported brake pedal position and accelerator pedal position that is not considered compatible. This is a plausibility/correlation type fault rather than a simple “high/low” electrical condition: the module compares the two inputs (and sometimes related signals) to confirm they make sense together. SAE J2012 defines how DTCs are structured and categorized; for P2299, the definition centers on the disagreement between these two pedal position inputs.

Quick Reference

  • System: Powertrain
  • Official meaning: Use the official definition provided by the data source for this code.
  • Standard: ISO/SAE controlled
  • Fault type: Plausibility (incompatible/correlation)
  • Risk level: Moderate — may trigger reduced throttle response or unexpected drivability limitations.

Symptoms

  • Warning light: Malfunction indicator lamp illuminated
  • Reduced power: Throttle limited or reduced engine power mode
  • Poor acceleration: Sluggish response to accelerator input
  • Intermittent hesitation: Momentary cut/limit during pedal transitions
  • Unstable idle: Idle fluctuation if torque management intervenes
  • Brake/traction messages: Driver information warnings related to brake/throttle plausibility

Common Causes

  • Brake pedal position (BPP) sensor out of calibration causing a reported brake-applied state that conflicts with accelerator input
  • Accelerator pedal position (APP) sensor out of calibration or drift leading to implausible pedal angle compared to other channels
  • Connector/contact issues at the brake pedal switch/sensor or accelerator pedal module (loose fit, backed-out terminals, corrosion)
  • Wiring harness faults (intermittent opens, high resistance, chafing) affecting BPP/APP signal circuits and creating mismatched readings
  • Shared reference/ground problems (unstable 5V reference or sensor ground) altering one sensor’s output relative to the other
  • Brake pedal switch misadjustment (where a discrete brake switch is used) reporting “applied” too early/late versus actual pedal travel
  • Aftermarket/incorrect pedal components (non-matching pedal module or brake switch type) creating incompatible signal characteristics
  • Control module software/logic issue where relearn/calibration is required after service, battery events, or module replacement (varies by vehicle)

Diagnosis Steps

Tools typically needed include a scan tool capable of reading live data (including brake pedal position/state and accelerator pedal position channels), viewing freeze-frame data, and clearing codes. A digital multimeter is useful for checking reference voltage, ground integrity, and connector pin fit. Access to vehicle-specific wiring diagrams and service procedures is important because sensor types and signal strategies vary by vehicle.

  1. Confirm the code and capture freeze-frame: Verify P2299 is active or stored, then record freeze-frame data (vehicle speed, throttle angle, brake status/position, accelerator position) to understand the operating conditions when incompatibility was detected.
  2. Check for related codes: Look for additional faults tied to brake switch/BPP sensor, APP sensor, throttle control, reference voltage, or module communication. Address codes that indicate reference/ground faults first because they can create multiple plausibility issues.
  3. Review live data for correlation: With key on/engine off, monitor BPP (or brake switch state) and APP channels. Slowly apply and release the brake while keeping the accelerator at rest; then slowly move the accelerator with the brake released. Watch for states that disagree (for example, brake applied when the pedal is released) or for unstable/jumpy values.
  4. Perform a plausibility “transition” test: Reproduce the conditions from freeze-frame if safe (for example, light throttle tip-in, then brake application). Log PIDs so you can see the exact moment brake state and accelerator position become incompatible.
  5. Inspect pedal assemblies and adjustment: Verify the brake pedal returns fully and the brake switch/sensor alignment and mounting are secure. On designs with an adjustable brake switch, confirm the switch is correctly positioned so it changes state at the specified point in pedal travel (varies by vehicle).
  6. Connector and harness inspection with a wiggle test: Inspect connectors at the brake pedal sensor/switch and accelerator pedal module for spread pins, corrosion, or water intrusion. While watching live PIDs, gently wiggle the harness and connector bodies to detect intermittent dropouts or sudden value jumps.
  7. Check reference voltage and sensor ground stability: Using wiring diagrams, identify the 5V reference and sensor ground circuits (if used). With the connectors backprobed, verify reference voltage is stable and ground has low resistance. If values fluctuate when loads change (lights, blower, etc.), focus on shared grounds or reference circuits.
  8. Signal integrity checks: Backprobe the BPP and APP signal circuits and compare voltage (or duty-cycle where applicable) behavior to live data while moving each pedal slowly. Look for dead spots, abrupt steps, or noise that would indicate a sensor issue or a high-resistance/open condition.
  9. Voltage-drop testing under load: If service info permits, perform voltage-drop tests across power and ground paths to the pedal sensors/modules while actuating the pedals. Excessive drop points to resistance in wiring, splices, or terminals that can skew sensor outputs and create incompatibility.
  10. Verify calibrations/relearns: Check service information for required brake switch setup, pedal position learning, or throttle/pedal relearn procedures after battery disconnects or component replacement. Perform the specified procedure and recheck for P2299.
  11. Clear codes and perform a confirmation drive: After repairs or adjustments, clear DTCs and complete a drive cycle similar to freeze-frame conditions while logging BPP/APP data to confirm the signals remain compatible and P2299 does not reset.

Professional tip: If P2299 is intermittent, prioritize recording a data log that includes brake state/position, accelerator position (all available channels), reference voltage (if available), and vehicle speed. A brief incompatibility event can set the code; the log helps pinpoint whether the mismatch originates from a single sensor glitch, a shared reference/ground disturbance, or a harness/connector intermittency.

Possible Fixes

  • Repair or replace damaged wiring/terminals between the brake pedal position input, accelerator pedal position sensors, and the control module; correct poor pin fit, corrosion, or moisture intrusion.
  • Verify and restore proper power supply and ground integrity for the pedal sensors and related circuits (as applicable by vehicle design), then clear codes and recheck for correlation faults.
  • Adjust, reinstall, or replace the brake pedal position sensor/switch if its signal is inconsistent or does not track pedal movement correctly.
  • Replace the accelerator pedal position sensor assembly if live data shows erratic, out-of-range, or non-matching sensor tracks during smooth pedal application.
  • Perform required relearn/calibration procedures for the accelerator pedal/brake pedal position signals after component replacement or connector repair (procedure varies by vehicle).
  • Update control module software if service information indicates a known calibration issue that can set a brake/accelerator incompatibility fault.

Can I Still Drive With P2299?

Driving with P2299 is not recommended unless the vehicle operates normally and no safety-related symptoms are present. Because this code indicates an incompatibility between brake pedal position and accelerator pedal position signals, the powertrain may limit throttle response, enter a reduced-power mode, or disable cruise-related functions to prevent unintended acceleration. If you experience reduced power, intermittent throttle response, warning messages, or the vehicle will not accelerate predictably, stop driving and arrange service or towing. If braking performance is affected, do not drive.

What Happens If You Ignore P2299?

If ignored, P2299 can lead to recurring reduced-power events, intermittent throttle inhibition, and unpredictable drivability concerns due to continued brake/accelerator signal mismatch. The fault may progress if the root cause is a degrading sensor, connector, or wiring issue, potentially increasing the frequency of limp mode and increasing the risk of stalling-like hesitation or inability to accelerate as expected. In many cases the malfunction indicator will remain on, and readiness monitors may not set, which can affect inspection/maintenance testing.

Related Codes

  • P2268 – Water in Fuel Sensor Circuit Intermittent
  • P2267 – Water in Fuel Sensor Circuit High
  • P2266 – Water in Fuel Sensor Circuit Low
  • P2265 – Water in Fuel Sensor Circuit Range/Performance
  • P2264 – Water in Fuel Sensor Circuit
  • P2230 – Barometric Pressure Circuit Intermittent
  • P2229 – Barometric Pressure Circuit High
  • P2228 – Barometric Pressure Circuit Low
  • P2227 – Barometric Pressure Circuit Range/Performance
  • P2226 – Barometric Pressure Circuit

Key Takeaways

  • P2299 indicates the brake pedal position and accelerator pedal position signals are not compatible per the control module’s plausibility checks.
  • Intermittent wiring/connector faults and sensor signal irregularities are common roots; confirm with live data and targeted circuit checks.
  • Reduced power or throttle inhibition may occur as a protective response; treat it as a safety-related drivability concern.
  • Fixes should be based on measured evidence: stable power/grounds, clean signal tracking, and correct correlation during road tests.
  • Calibration/relearn steps after repairs may be required and vary by vehicle service information.

FAQ

What does “brake pedal position / accelerator pedal position incompatible” mean?

It means the control module detected a plausibility mismatch between the brake pedal position input and the accelerator pedal position input. In normal operation, these signals follow expected relationships (for example, braking may be expected to coincide with reduced throttle demand), and when the relationship is outside programmed limits for a period of time, P2299 can set.

Will P2299 cause reduced power or no acceleration?

Yes, it can. When the module cannot trust the relationship between the brake and accelerator signals, it may limit engine torque, reduce throttle response, or inhibit acceleration to protect against unintended acceleration scenarios. The exact strategy and severity vary by vehicle.

Do I need to replace both the brake and accelerator sensors to fix P2299?

Not necessarily. The correct repair depends on which input is incorrect and why. Use scan-tool live data to confirm which signal is implausible, then verify wiring, connector integrity, power/grounds (if applicable), and sensor output. Replace only the component proven faulty and complete any required relearn/calibration procedure.