P1464 — Unable To Pull Vacuum In Tank

P1464 — Unable To Pull Vacuum In Tank. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: open or shorted wiring in the circuit, corroded, loose or damaged connector, control module driver fault.

Meaning for brands

Chery

For Ford vehicles

A/C demand – out of self-test range

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm P1464 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the unable to pull vacuum in tank for damage, corrosion, chafing or poor contact.
Subsystem check Measure reference voltage, ground and signal continuity at the component connector.
Subsystem check Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P1464 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P1464 (parts and labor, USD, independent shop rates): Control module repair: $300–$1,000; Repair wiring or connectors: $80–$250; Replace the faulty sensor or actuator: $150–$500. Overall, fixing P1464 usually costs between $80 and $1,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What does OBD2 code P1464 mean?

What is the most common cause of P1464?

The most common causes are: open or shorted wiring in the circuit, corroded, loose or damaged connector, control module driver fault.

How do I diagnose P1464 myself?

Start with a scan: confirm P1464, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the sensor and actuator circuits, and verify the suspect component against live data before buying parts.

Will P1464 clear itself?

Sometimes P1464 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

Is it safe to drive with P1464?

In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

When your scan tool pulls code P1464, it is reporting that the engine control module detected an inability to draw vacuum from the fuel tank system. This falls under the powertrain category of OBD2 faults, which covers engine and transmission related problems. The control unit sets P1464 after comparing live sensor and actuator readings against factory-specified thresholds, typically across multiple drive cycles.

The fuel tank ventilation system relies on a network of valves, hoses and actuators to manage vapor recovery and maintain proper tank pressure. When one of these components cannot generate the required vacuum, the PCM recognizes the deviation and triggers P1464. The module also captures a freeze frame snapshot at the moment of failure, recording engine speed, load, coolant temperature and vehicle speed. Reviewing this data first often points you directly at the root cause instead of chasing unrelated symptoms.

Symptoms of P1464

The fuel tank ventilation system may stop working intermittently or fail entirely when P1464 is active. The Check Engine Light illuminates and stays on until the fault clears. Depending on which component is affected, the vehicle could enter limp-home mode with reduced power output. Some drivers report a noticeable spike in fuel consumption due to improper vapor management. In rare cases, hard starting or rough idle may accompany the fault if tank pressure cannot be properly regulated.

Common causes of P1464

Wiring problems account for a large percentage of P1464 failures — an open circuit, short to ground, or chafed insulation prevents the control signals from reaching the actuator. Corroded, loose or physically damaged connectors create high resistance that mimics component failure. A weak or failed ground connection at the fuel tank ventilation valve starves the circuit of proper reference voltage. Blown fuses feeding the tank vent circuit cut power entirely. Finally, the control module itself can develop an internal driver fault that prevents it from commanding the system properly.

How to diagnose P1464

Connect a professional OBD2 scanner and confirm that P1464 is stored in the ECU, then save the freeze frame data to understand the engine conditions when the fault occurred. Look for any related diagnostic trouble codes — secondary codes often expose the actual faulty component rather than the symptom. Check manufacturer technical service bulletins for your specific make and model on the official website or through nhtsa.gov, as many P0xxx codes have documented factory fixes or software calibrations. Perform a thorough visual inspection of the wiring harness and connectors related to the tank vacuum system, looking for damaged insulation, corrosion buildup, broken locks or bent pins. Use a multimeter to verify reference voltage, ground integrity and signal continuity at the component connector against factory specifications. Perform a wiggle test on the harness while monitoring live data — any signal dropouts indicate an intermittent wire break. Finally, clear the code and complete a full drive cycle under the same conditions captured in the freeze frame to verify P1464 does not return.

Repair options and costs for P1464

Target the most affordable and probable causes before replacing expensive components. Wiring repair or connector replacement typically runs $80 to $250 depending on accessibility and labor time. If the vent valve, purge solenoid or associated sensor has failed outright, expect to pay $150 to $500 for the part plus installation. When the PCM itself contains the faulty driver circuit, module-level repair or replacement ranges from $300 to $1,000. Most shops charge between $80 and $150 per hour for diagnostic labor on top of parts costs.

Total cost to fix P1464

The final bill hinges entirely on which component triggered the code. A straightforward wiring repair or connector fix usually falls in the $80 to $250 range. Replacing a failed tank vent valve or purge solenoid typically costs $150 to $500 including labor. The most expensive scenario — a faulty control module — runs $300 to $1,000. Overall, fixing P1464 typically costs between $80 and $1,000. Getting an accurate diagnosis before purchasing parts always saves money since the priciest fix is rarely the culprit.

Can you drive with P1464?

P1464 carries a short-term severity rating, meaning the vehicle remains drivable in most cases, though you may notice reduced performance or an inoperative auxiliary system. Avoid delaying repairs if you experience stalling, failure to start, or warnings affecting the brakes and steering — treat those symptoms as urgent.