The P2564 Turbocharger Boost Control Position Sensor Low code sets when your ECM detects a voltage signal from the turbo boost control position sensor that falls below the expected calibrated range. In plain terms, the sensor that tells the computer where your turbo’s actuator or wastegate arm is sitting has dropped its signal to a value that can’t be right. When that happens, the ECM can no longer trust boost control, and it will often derate the engine to protect the turbo and driveline.
This is a common code on modern diesels running electronically controlled actuators, and it trips up a lot of techs because the fault lives at the intersection of mechanics, electronics, and boost management. At PT Turbo, we’ve been rebuilding and supplying turbochargers since 1978, more than 45 years, and we see P2564 cross the bench regularly. Here’s how to diagnose it right the first time.
What P2564 Actually Means
Every electronically controlled turbo actuator has a position feedback sensor built in. On a variable geometry turbo (VGT), that sensor reports vane position. On a wastegated setup with an electronic actuator, it reports wastegate arm position. The ECM commands a target position, then reads the feedback sensor to confirm the actuator got there.
P2564 specifically means the feedback voltage is low, typically below roughly 0.5 volts on a 0 to 5V circuit, or sometimes below 10 percent of the sensor’s sweep range. The ECM interprets this as either a short to ground, an open reference, or a physically stuck actuator that isn’t moving where commanded.
If you’re chasing a related boost problem, it’s worth reading our companion guides on the P0299 underboost code and the P0046 vane position sensor circuit fault, since they frequently appear alongside P2564.
Common Symptoms of P2564 Turbocharger Boost Control Position Sensor Low
The way this code shows up depends heavily on how far out of range the signal has drifted. A momentary glitch feels different from a fully dead sensor. Here’s how symptoms typically scale with severity.
| Severity | What You’ll Notice | Drivability Impact |
|---|---|---|
| Mild / Intermittent | Check engine light comes and goes, minor hesitation under load | Slight power loss, boost occasionally soft |
| Moderate | Persistent CEL, noticeable turbo lag, poor throttle response | Reduced boost, sluggish acceleration, possible black smoke |
| Severe | Engine derate / limp mode, no boost control, hard start under load | Major power loss, cannot pull grades, safe-mode operation |
Because the ECM loses trust in boost feedback, it usually defaults the actuator to a fail-safe position. On many VGT platforms that means the vanes park open, giving you low boost and a truck that feels gutless. On wastegated engines, the gate may default open or closed depending on the calibration, which can cause either underboost or, less commonly, overboost. If you’re seeing high boost instead, check our P0234 overboost code guide.
Root Causes: What to Check Before Condemning the Turbo
The most expensive mistake with P2564 is replacing a whole turbocharger when the actual failure is a $90 actuator or a chafed wire. Work through the causes in order of probability, not price.
- Failed position sensor inside the actuator. The Hall-effect or potentiometer element wears out or shorts internally. This is the single most common root cause.
- Damaged wiring or connector. Heat, vibration, and oil migration corrode the actuator connector. Look for green pins and broken locking tabs.
- Stuck or seized actuator linkage. Carbon and soot bind the vanes or wastegate arm so the actuator physically can’t move, and the sensor reports a pinned low value.
- Open or shorted 5V reference / signal / ground. A pinched harness against the block or exhaust manifold will drag the signal low.
- ECM or connector ground fault. Rare, but a corroded ECM ground can skew every sensor reference.
On heavy-duty applications like the Caterpillar C13, actuator and sensor faults are a known weak point. If you run that platform, our Caterpillar C13 turbocharger guide covers the specifics.
Step-by-Step Diagnosis
You’ll need a scan tool capable of reading actuator commanded vs actual position, a digital multimeter, and the wiring diagram for your specific engine. Don’t guess at pin assignments, confirm them.
1. Read Freeze Frame and Live Data
Pull the freeze frame to see the conditions when P2564 set. Then watch commanded position against actual position. If commanded sweeps but actual stays pinned low, you have either a dead sensor or a stuck actuator.
2. Inspect the Connector and Harness
Disconnect the actuator connector. Look for corrosion, spread pins, oil intrusion, and heat damage. Wiggle-test the harness while watching live data. Any flicker points to a wiring fault, not the sensor.
3. Verify Reference Voltage and Ground
Key on, engine off. Back-probe the connector. You should see roughly 5V on the reference wire and a clean ground under 0.1V drop. Missing reference voltage means the fault is upstream in the harness or ECM, not the actuator.
4. Test Actuator Movement
Command the actuator through its range with a bidirectional scan tool. Watch and listen. If it doesn’t move or moves roughly, the internal motor or linkage is failing. A binding VGT mechanism, per the principles of variable-geometry turbocharger design, will stall the actuator and drag the sensor signal low.
5. Check the Signal Sweep
Manually move the linkage by hand (engine off, actuator disconnected from load if possible) while monitoring the signal voltage. A healthy sensor sweeps smoothly from low to high. Dropouts, dead spots, or a signal stuck under 0.5V confirm a bad position sensor.
Repair Options: Actuator vs Complete Turbo
Once you’ve isolated the fault, you have three real paths: replace the pneumatic or electronic actuator, install a remanufactured turbo, or rebuild the unit you have. The right call depends on the condition of the center section and the vanes.
If the turbo spins freely, holds oil, and the only problem is the actuator or its integrated sensor, replace the actuator. It’s the fastest and cheapest fix. PT Turbo stocks OE-grade replacements for the most common Garrett and Mitsubishi platforms:
- Garrett Pneumatic Actuator 757979-5102, available from PT Turbo for $240.94, view the Garrett 757979-5102 actuator here.
- Mitsubishi Turbocharger Pneumatic Actuator TD03 49S3118761, available for $104.33, view the Mitsubishi TD03 49S3118761 actuator here.
- Mitsubishi Pneumatic Actuator 4918918935, available for $83.99, view the Mitsubishi 4918918935 actuator here.
- Garrett Pneumatic Actuator 445963-0040, available for $465.52, view the Garrett 445963-0040 actuator here.
If the vanes are carboned or the shaft has play, replacing the actuator alone won’t hold. In that case a remanufactured turbocharger or our full turbocharger rebuild service is the durable answer. Here’s how the options compare.
| Option | Best When | Relative Cost | Expected Life |
|---|---|---|---|
| Replace actuator only | Turbo core is healthy, sensor/actuator failed | $ | Full, if core is sound |
| Remanufactured turbo | Vanes carboned, shaft play, or high mileage | $$ | Like-new with warranty |
| Rebuild existing unit | OE core you want to keep, no reman available | $$ | Like-new with warranty |
| New OEM turbo | Warranty requirement or no reman core | $$$$ | Full factory life |
Preventing P2564 From Coming Back
A new actuator on a dirty turbo is a repeat failure waiting to happen. Address the underlying causes so the code stays gone.
- Keep EGR and DPF systems healthy. Excess soot from a failing EGR system is what carbons up vanes and binds linkage
Cross-Reference & Superseded Part Numbers
The turbochargers covered in this article match or supersede the following OEM and manufacturer part numbers. If you are searching by part number, these are the units stocked by PT Turbo for this application:
445963-151 • 448734-5 • 773326-0001 • 911984-5003S • 953223-5001S • GTX2867R+Bolt-on+Turbo • GTX3071R+Bolt-on+Turbo • PTT-FIE-007 • PTT-FIE-008 • PTT-FIE-009 • PTT-FIE-017 • PTT-FIE-021 • PTT-FIE-022 • PTT-FIE-025 • PTT-FIE-026 • PTT-FOC-010 • PTT-FOC-011 • PTT-FOC-012 • PTT-FOC-013 • PTT-FOC-020 • PTT-FOC-030 • PTT-FOC-033 • PTT-FOC-036 • PTT-FOC-050 • PTT-FOC-051 • PTT-FOC-052 • PTT-FOC-056 • PTT-FOC-064 • PTT-FOC-071 • PTT-FOC-076 • PTT-FOC-086 • PTT-FOC-096 • PTT-FOC-B11 • PTT-FOC-B12 • PTT-FOC-B15 • PTT-FOC-B16 • PTT-FOC-B17 • PTT-FOC-B22 • PTT-FOC-B24 • PTT-HGC-004 • PTT-HGC-069 • PTT-HSG-405 • PTT-MS3-003 • PTT-MS3-007 • PTT-MUS-005 • PTT-MUS-010 • PTT-RB2-002 • PTT-SR2-002 • PTT-STC-001 • PTT-SUB-096 • PTT-SUB-100 • PTT-SUB-105 • PTT-TBO-002 • PTT-TBO-023 • PTT-TBO-066 • PTT-TBO-107 • PTT-TBO-345 • PTT-TBO-450 • PTT-TBO-592 • PTT-TBO-602 • PTT-TBO-763 • PTT-TBO-764 • PTT-TBO-770 • PTT-TBO-818 • PTT-TBO-841 • PTT-TBO-846 • PTT-TBO-847 • PTT-TBO-849 • PTT-TBO-889 • PTT-TBO-965 • PTT-TBO-B34 • PTT-TBO-B35 • PTT-TBO-C15 • PTT-TBO-C16 • PTT-TBO-F83 • PTT-TBO-F84 • PTT-TBO-J26 • PTT-TBO-J57 • PTT-TBO-N23 • PTT-TBO-N24 • PTT-TBO-R94 • PTT-TBO-R95 • PTT-VEVO-026 • PTT-VEVO-158 • PTT-VEVO-189 • PTT-VEVO-200 • PTT-VSRT-007 • PTT-VVW-004 • PTT-VVW-042 • PTT-VVW-047 • PTT-WGT-019 • PTT-WGT-032 • PTT-WGT-037 • PTT-WGT-093 • PTT-WGT-103 • PTT-WGT-108 • PTT-WGT-109 • TIL-BOV-007 • TIL-WGT-035 • stock+location+fsi/tsi+option+3
Can’t find your number above? Contact PT Turbo — our team has been matching part numbers since 1978.
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