P2CD9: Turbocharger/Supercharger Boost Sensor D Circuit High
The ECM detects a circuit high fault on the turbocharger/supercharger boost sensor d circuit. Reading cannot be used reliably for control.
What P2CD9 means
P2CD9 is a generic OBD-II powertrain code in the fuel & air group. In plain English: the computer sees a voltage on that circuit that is higher than it should ever be — often an open ground, a short to power, or a failed sensor.
- Check engine light
- Usually on
- Emissions-related
- Yes — can fail inspection
- Limp mode possible
- Yes
- Drive cycle to clear
- Not required
Get it fixed
Post this code once and get quotes from local mechanics. Free to post.
Makes the repair and parts links below specific to your car. Kept in this browser only.
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Common causes
- 01Signal wire shorted to B+Most likely
- 02Open sensorPossible
- 03Connector pins corroded - high contact resistanceLess likely
Can I drive with P2CD9?
Not recommended beyond getting it to a shop.
This fault can put the engine or transmission in limp mode with reduced power, which can make merging and passing unsafe. Have it diagnosed as soon as possible.
Why we rate it urgent
- Can put the vehicle in limp mode (reduced power)
- Turns on the check engine light
- Emissions-related: will usually fail an OBD inspection
Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.
How to diagnose P2CD9
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just P2CD9. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Fix other faults first
If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.
- 3
Test the circuit
Inspect the wiring and connector at the turbo boost sensor d and wiring harness for damage, corrosion or chafing. With a multimeter, check supply voltage, ground and signal against the specifications in the service manual for your vehicle.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Signal wire shorted to B+; open sensor; connector pins corroded - high contact resistance. Test before replacing parts.
- 5
Check for recalls and service bulletins
Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.
- 6
Clear the code and verify the repair
After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.
P2CD9 repair cost estimate
Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.
- DIY difficulty
- Easy
- Good DIY job?
- Yes, with a scan tool
Basic hand tools; a common first DIY job.
Parts and systems involved
- Turbo boost sensor D
- Wiring harness
- ECM
P2CD9 FAQ
What does P2CD9 mean?
P2CD9 means “Turbocharger/Supercharger Boost Sensor D Circuit High”. The ECM detects a circuit high fault on the turbocharger/supercharger boost sensor d circuit. Reading cannot be used reliably for control.
Is P2CD9 serious? Can I keep driving?
We rate P2CD9 as urgent severity. Not recommended beyond getting it to a shop. This fault can put the engine or transmission in limp mode with reduced power, which can make merging and passing unsafe. Have it diagnosed as soon as possible.
What causes P2CD9?
The most common causes, from most to least likely: Signal wire shorted to B+; Open sensor; Connector pins corroded - high contact resistance. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix P2CD9?
Typical labor is about $40–$250 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.
Can I fix P2CD9 myself?
DIY difficulty is easy. Many owners can handle it with a scan tool, a multimeter and basic hand tools. Always confirm the cause before buying parts.
Will P2CD9 clear itself?
If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.