P2564 – Turbocharger Boost Control Position Sensor Circuit Low

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Circuit Low

Definition source: SAE J2012/J2012DA (industry standard)

P2564 indicates the powertrain control module has detected a low electrical signal condition in the turbocharger boost control position sensor circuit. In practical terms, the module is seeing the position feedback signal lower than expected for the current operating conditions and commanded boost control movement. This is a circuit-level fault type (low input), so diagnosis should focus on wiring integrity, connector condition, power/ground quality, and signal plausibility before replacing components. DTC behavior, enabling criteria, and what the module does in response (such as limiting boost) can vary by vehicle, so confirm the exact pinout, circuit description, and test specifications using the correct service information for the vehicle you are working on.

What Does P2564 Mean?

P2564 – Turbocharger Boost Control Position Sensor Circuit Low means the control module has determined the turbocharger boost control position sensor circuit is reporting a low input. The “position sensor” feedback is used to indicate the actual position of the boost control mechanism (design varies by vehicle) so the module can compare commanded versus actual movement. Because the official definition is “Circuit Low,” the diagnostic direction is electrical: the signal may be pulled low by a short-to-ground, loss of sensor power/feed, poor ground reference, excessive resistance causing signal drop, or a sensor output stuck low. The DTC structure follows SAE J2012 conventions, but the meaning is defined by the official title and description.

Quick Reference

  • Subsystem: Turbocharger boost control position sensor feedback circuit (signal, power, and ground paths as applicable).
  • Common triggers: Signal circuit pulled low, loss of sensor supply/feed, high resistance in wiring causing low signal, or poor connector contact at the sensor/actuator or module.
  • Likely root-cause buckets: Wiring/connector faults, sensor fault, actuator assembly fault (if integrated), power/ground integrity issues, or control module/terminal concerns (less common).
  • Severity: Often moderate to high; may cause reduced power and protective boost limitation; drivability impact varies by vehicle strategy.
  • First checks: Visual inspection of harness routing and connectors, confirm secure connector seating, check for shared power/ground issues, and review freeze-frame data.
  • Common mistakes: Replacing the turbocharger or actuator without verifying the low-input condition is caused by a wiring/power/ground problem.

Theory of Operation

The turbocharger boost control system uses a movable mechanism to regulate boost. A position sensor provides feedback to the control module so it can confirm that the mechanism is moving as commanded and is reaching the desired position. Depending on vehicle design, the position sensor may be a standalone component or integrated into a boost control actuator assembly. The sensor typically receives a regulated supply and ground (or a defined reference strategy) and returns a position signal to the module.

The module continuously monitors the position feedback signal for electrical validity. When the signal is consistently too low for the monitor’s criteria, it interprets this as a “circuit low” condition rather than a mechanical performance issue. To protect the powertrain, the module may limit boost command, substitute a default value, or restrict torque output. Exact monitor conditions and responses vary by vehicle and must be verified in service information.

Symptoms

  • Reduced power: Noticeable loss of acceleration, especially under load, due to boost limiting or torque reduction.
  • Limited boost: Boost may be capped, delayed, or inconsistent as the module enters a protective control mode.
  • Warning light: Malfunction indicator lamp may illuminate; additional powertrain warnings may appear depending on the platform.
  • Poor drivability: Hesitation, flat spots, or surging can occur if boost control is operating with substituted feedback.
  • Increased smoke: Exhaust smoke may increase under certain conditions if boost and fueling are not optimally matched (varies by vehicle strategy).
  • Failsafe behavior: The system may default to a conservative boost position, affecting throttle response and shift feel on some vehicles.

Common Causes

  • Short-to-ground in the turbocharger boost control position sensor signal circuit (including chafed insulation contacting engine or chassis ground)
  • Open power/feed to the sensor (such as an open reference supply or sensor supply circuit causing the signal to be pulled low)
  • High resistance in the sensor power or ground circuits (corrosion, partially broken conductor, or poor terminal tension creating excessive voltage drop that drives the signal low)
  • Connector problems at the sensor or control module (water intrusion, backed-out pins, spread terminals, pin fretting, or improper connector seating)
  • Faulty turbocharger boost control position sensor (internal short or biasing that produces a low signal)
  • Fault in the turbocharger boost control actuator assembly if the position sensor is integrated (internal harness damage or internal circuit fault)
  • Harness routing/retainer failure leading to intermittent contact with hot or moving components (creating recurring low-input events)
  • Control module input circuit issue (less common; consider after external circuit and sensor checks pass)

Diagnosis Steps

Useful tools include a scan tool capable of reading freeze-frame and live data and clearing codes, a digital multimeter, and access to vehicle-specific wiring diagrams and connector views. A back-probing method and terminal inspection tools are recommended to avoid damage. If available, use a breakout lead or test harness to measure circuits under load without piercing insulation.

  1. Confirm the code and capture data: Verify P2564 is active or stored. Record freeze-frame data and note any related powertrain codes. Clear codes and see whether P2564 resets immediately or after a drive cycle; this helps separate hard electrical faults from intermittent ones.
  2. Identify the exact circuit layout (varies by vehicle): Using service information, determine whether the position sensor is standalone or integrated into the boost control actuator, and identify the sensor circuits (signal, power/feed, and ground) and the module pin locations used for this input.
  3. Initial visual inspection (engine off): Inspect the sensor/actuator connector and harness routing from the turbocharger area back toward the main harness. Look for abrasion, melted insulation, oil saturation, missing clips, contact with sharp edges, and signs of water intrusion or corrosion at terminals.
  4. Connector and terminal integrity check: With connectors disconnected, inspect for bent pins, backed-out terminals, spread terminal tension, and seal damage. Correct any mechanical terminal issues before electrical testing; a good-looking connector can still have poor pin fit.
  5. Check for a signal short-to-ground: With the sensor disconnected and ignition state as required by service info, test the signal circuit for unintended continuity to ground. If the signal circuit shows a ground path when it should not, isolate by unplugging intermediate connectors (if equipped) to locate the harness segment causing the short.
  6. Verify sensor power/feed presence: Reconnect the module side as needed and test the sensor’s power/feed circuit at the sensor connector (do not force pins). If power/feed is missing or unstable, trace the circuit back through the harness and related splices/connectors per wiring diagrams, checking for opens and high resistance.
  7. Verify sensor ground quality with voltage-drop testing: With the circuit powered and under load as directed by service info, perform a voltage-drop test on the sensor ground path between the sensor ground terminal and a known-good ground point. Excessive drop indicates resistance in the ground circuit (corrosion, loose terminal, damaged wire, or poor ground point).
  8. Check the signal line for unwanted pull-down under load: With the sensor connected, monitor the position sensor signal in live data while gently loading the harness (light tug) and observing if the signal collapses low. If possible, compare scan tool signal behavior to multimeter readings at the connector to distinguish a wiring issue from a module interpretation issue.
  9. Perform a controlled wiggle test: While logging live data and engine conditions as required, wiggle the harness at known stress points: near the sensor/actuator, at brackets, near heat shields, and where the harness transitions to the main loom. If the signal drops low or the code sets during movement, focus on that segment for an intermittent short-to-ground or high-resistance fault.
  10. Sensor/actuator isolation test: If wiring checks pass, follow service info for an isolation procedure to determine whether the sensor output remains low independent of harness condition. If the position sensor is integrated into the actuator, verify any internal connector/harness (where serviceable) and retest before replacement.
  11. Module-side circuit verification: If the external circuit and sensor/actuator test good, confirm continuity and integrity from the sensor connector to the control module connector (including checking for pin damage at the module). If all wiring and the sensor are verified, consider a control module input fault as a last step and follow service information for any required confirmation tests.

Professional tip: When chasing a circuit-low fault, prioritize finding the condition that is actively pulling the signal down: a short-to-ground, an open in the sensor power/feed, or resistance in the return path. Use voltage-drop testing with the circuit powered and live-data logging during a wiggle test; intermittent low-input events are often missed by static continuity checks performed with everything unplugged.

Need wiring diagrams and factory-style repair steps?

Powertrain faults often require exact wiring diagrams, connector pinouts, and guided test steps. A repair manual can help you confirm the cause before replacing parts.

Factory repair manual access for P2564

Check repair manual access

Possible Fixes & Repair Costs

Repair costs for P2564 vary widely because the root cause can be as simple as a connector issue or as involved as harness repair or component replacement. Labor time depends on access to the turbocharger boost control position sensor circuit and the testing needed to confirm the fault.

  • Repair wiring damage: Fix chafed, pinched, melted, or broken wires in the turbocharger boost control position sensor signal, reference, or ground circuits after confirming the low-input condition.
  • Service connectors: Clean corrosion, correct terminal spread/poor pin fit, reseat connectors, and ensure proper locking where a poor connection is pulling the circuit low.
  • Restore power/ground integrity: Repair open power feed, compromised ground path, or excessive resistance found by voltage-drop testing that causes the sensor circuit to read low.
  • Replace the boost control position sensor: Replace only after verifying correct power/ground and confirming the sensor output remains low with a known-good circuit.
  • Inspect/replace related actuator if integrated: On designs where the position sensor is integrated with the boost control actuator, replace the assembly only after circuit tests prove the fault is not in the harness or connectors.
  • Module-side repair as last step: If all external circuits and components test good and the low input is confirmed at the module pin, follow service information for module pin checks and replacement/programming requirements (varies by vehicle).

Can I Still Drive With P2564?

Sometimes, but drive conservatively and only if the vehicle remains stable and predictable. A circuit-low fault in the turbocharger boost control position sensor circuit can trigger reduced power and inconsistent boost control, which may affect merging and passing. If you experience stalling, severe hesitation, a no-start, or any warning that affects braking or steering, do not drive—have the vehicle towed and diagnosed.

What Happens If You Ignore P2564?

Ignoring P2564 can lead to persistent reduced performance, poor drivability, and repeated limp/derate events as the control module limits boost to protect the powertrain. Continued operation with unstable boost control feedback may increase exhaust temperatures and mechanical stress in some operating conditions, and the ongoing electrical fault can worsen due to heat, vibration, or moisture damage to wiring and connectors.

Compare nearby sensor turbocharger trouble codes with similar definitions, fault patterns, and diagnostic paths.

  • P2592 – Turbocharger Boost Control Position Sensor “B” Circuit Low
  • P2566 – Turbocharger Boost Control Position Sensor Circuit Intermittent
  • P2565 – Turbocharger Boost Control Position Sensor Circuit High
  • P2563 – Turbocharger Boost Control Position Sensor Circuit Range/Performance
  • P2562 – Turbocharger Boost Control Position Sensor Circuit
  • P2599 – Turbocharger Boost Control Position Sensor Circuit Range/Performance

Key Takeaways

  • P2564 is electrical: It indicates a circuit-low condition in the turbocharger boost control position sensor circuit, not a confirmed mechanical turbocharger failure.
  • Start with basics: Connector condition, harness routing, and power/ground integrity are frequent causes of low-input faults.
  • Test before replacing parts: Confirm the low signal at the sensor and at the module, and use voltage-drop testing to find resistance issues.
  • Expect drivability changes: Reduced power and limited boost control may occur depending on vehicle strategy.
  • Verify with service info: Pinouts, wire colors, and exact test procedures vary by vehicle and must be confirmed in the correct documentation.

Vehicles Commonly Affected by P2564

  • Turbocharged vehicles: Platforms using a turbocharger with position feedback for boost control.
  • Electronic boost control systems: Systems that use an actuator with a position sensor for closed-loop control.
  • High-heat engine bays: Vehicles where harnesses run close to hot exhaust/turbo components, increasing risk of insulation damage.
  • High-vibration applications: Vehicles with frequent load changes where connectors and terminals can loosen over time.
  • Moisture-exposed routing: Vehicles with connectors located low in the engine compartment or near splash paths.
  • Recent repair history: Vehicles that have had turbo/actuator, engine, or harness work where connectors may be left partially seated.
  • Aftermarket wiring modifications: Vehicles with spliced circuits or non-OE routing that can introduce resistance or shorts to ground.

FAQ

Does P2564 mean the turbocharger is bad?

No. P2564 means the control module detected a low electrical signal in the turbocharger boost control position sensor circuit. Mechanical turbocharger problems are possible on any system, but this DTC specifically points to an electrical low-input condition that must be confirmed with circuit testing.

What electrical problems most commonly cause a “circuit low” code here?

The most common causes are a short-to-ground on the signal circuit, an open or high-resistance power feed to the sensor, a poor ground, corrosion or water intrusion in connectors, or terminal tension problems that pull the signal down. The correct cause must be identified by testing because symptoms can overlap.

Can a weak battery or charging issue cause P2564?

It can contribute on some vehicles, especially if system voltage drops enough to affect sensor reference or module operation, but it should not be assumed. If multiple low-voltage or communication codes are present, address baseline power/charging health first, then retest for P2564.

Should I replace the sensor immediately if live data is stuck low?

Not without confirming the circuit. A stuck-low reading can be caused by a short-to-ground, an open power feed, or a poor ground that forces the signal low even with a good sensor. Verify power, ground, connector integrity, and signal behavior at the sensor and at the module before replacing parts.

Why does the code come and go over bumps or when the engine moves?

Intermittent circuit-low events often point to a harness/connector issue such as a broken conductor inside insulation, poor pin fit, or chafing that intermittently contacts ground. A wiggle test and connector inspection, combined with live-data logging during movement, can help pinpoint the fault location.

Always confirm wiring diagrams, connector views, and the correct test procedure in the service information for the specific vehicle before repairs.