P1302 — Injector High Sides Shorted Together

OBD2 code P1302 flags a problem with the fuel delivery and mixture control (injector high sides shorted together). Short, gentle driving to a shop is usually possible. Common culprits: vacuum or intake leaks skewing the mixture, weak fuel pump or clogged fuel filter, clogged or leaking fuel injectors.

For Ford vehicles

boost calibration – signal too low

powertrain (engine/transmission)

Is it safe to drive?

Drive with caution Drive with caution. Mixture and fuel-pressure faults can cause stalling, hesitation in traffic and — when severe — catalyst damage. Avoid long trips until diagnosed.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm P1302 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 fuel delivery and mixture control for damage, corrosion, chafing or poor contact.
Subsystem check Measure fuel pressure at the rail and compare with factory specification at idle and under load.
Subsystem check Check short-term and long-term fuel trims in live data to see which way the mixture is off.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P1302 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P1302 (parts and labor, USD, independent shop rates): Replace the fuel pump: $400–$900; Replace the pressure regulator or sensor: $150–$450; Replace the fuel filter: $80–$200; Clean or replace injectors: $200–$800. Overall, fixing P1302 usually costs between $80 and $900. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

How do I diagnose P1302 myself?

Start with a scan: confirm P1302, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the fuel delivery and mixture control, and verify the suspect component against live data before buying parts.

What does OBD2 code P1302 mean?

Will P1302 clear itself?

Sometimes P1302 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 P1302?

Drive with caution. Mixture and fuel-pressure faults can cause stalling, hesitation in traffic and — when severe — catalyst damage. Avoid long trips until diagnosed.

What are the symptoms of P1302?

Drivers most often notice: fuel smell in severe cases, increased fuel consumption, Check Engine Light on, rough idle and hesitation.

When your scanner pulls code P1302, it is telling you that the engine control module has detected a short between the high-side circuits of the fuel injectors. This falls within the powertrain category of OBD2 codes, which means the issue directly affects how fuel is delivered and metered into the cylinders. The injector high-side circuits carry the power signal that opens each injector; when two or more of these circuits become shorted together, the module can no longer control fuel delivery accurately, and it logs this fault.

The powertrain control module does not set P1302 based on a single bad reading. It requires the fault condition to appear repeatedly under specific driving conditions before illuminating the check engine light. This is intentional — it prevents false alarms from temporary electrical glitches. When the module stores P1302, it also captures a freeze frame snapshot showing engine load, RPM, coolant temperature, and vehicle speed at the moment the fault was detected. That snapshot is your most valuable clue because it tells you exactly what conditions triggered the code, allowing you to reproduce those circumstances during testing.

Symptoms of P1302

P1302 affects fuel metering and combustion quality, so you will notice driveability problems before the check engine light appears:

Check Engine Light illuminated on the dashboard
Rough idle with noticeable engine hesitation during acceleration
Fuel smell, especially when the fault is severe
Higher than normal fuel consumption
Loss of engine power when the vehicle is under load
Extended cranking time or difficulty starting the engine

Common Causes

The high-side injector short that triggers P1302 rarely appears without an underlying problem in the fuel delivery system. Technicians find these root causes most frequently:

A failing or wiring-damaged fuel rail pressure sensor
Clogged, leaking, or electrically compromised fuel injectors
Use of contaminated or wrong-type fuel
A faulty fuel pressure regulator
A weak fuel pump or a fuel filter blocked with debris

How to Diagnose P1302

Effective diagnosis follows a logical path from electrical checks to fuel system measurements. Follow these steps in order:

Connect an OBD2 scanner and confirm P1302 is stored. Record the freeze frame data — note the engine load, RPM, coolant temperature, and vehicle speed recorded when the fault occurred.
Check for any other stored diagnostic trouble codes. Related codes often point to the underlying cause, such as low fuel pressure or sensor circuit faults. Review manufacturer technical service bulletins for your specific make and model — many P0xxx codes have documented factory fixes or software updates available through the manufacturer website or NHTSA.
Perform a visual inspection of the wiring harness and connectors associated with the fuel injectors and fuel rail pressure sensor. Look for damaged insulation, corrosion at the pins, chafing from contact with engine components, or loose connections.
Measure fuel system pressure at the rail using a gauge and compare the reading to factory specifications. Check pressure at idle and again while simulating the load conditions recorded in the freeze frame.
Monitor short-term and long-term fuel trim values in the scanner's live data stream. Trims that spike in one direction indicate whether the mixture is running lean or rich.
Clear the code and complete a full drive cycle, making sure to replicate the conditions from the freeze frame data. Confirm that P1302 does not return before considering the repair complete.

Repair Options and Costs

Address the cheapest and most common problems before committing to expensive component replacements. Parts and labor estimates below reflect typical independent shop rates in USD:

Fuel pump replacement: $400–$900
Fuel pressure regulator or sensor replacement: $150–$450
Fuel filter replacement: $80–$200
Fuel injector cleaning or replacement: $200–$800

Most P1302 repairs end up costing between $80 and $900 depending on which component is at fault. Spending time on accurate diagnosis before purchasing parts almost always saves money — the highest-priced repair scenario is rarely where you should start.

Can You Drive With P1302?

Drive with caution. Faults in the fuel metering and pressure system can produce stalling, hesitation during acceleration, and unpredictable engine behavior in traffic situations. When the engine runs rich or lean enough to trigger P1302 continuously, unburned fuel can enter the exhaust and damage the catalytic converter. It is wise to avoid long trips until the problem has been properly diagnosed and repaired.