What Does P1262 Mean?
The ECM has detected a high-to-low side short circuit in the cylinder #2 fuel injector driver circuit. The high-side power and low-side control wires for cylinder #2's injector are making unintended electrical contact, which can result in uncontrolled injector operation or a complete misfire on that cylinder. The engine will likely run rough with reduced power.
Safety Warning
A shorted injector driver can cause persistent misfires leading to loss of power, rough idle, and potential catalytic converter damage from unburned fuel. An uncontrolled injector can also cause cylinder wash and accelerated engine wear. Risk of ECM driver damage if the short persists.
Common Causes
35%
Chafed or heat-damaged injector wiring harness with high and low side wires shorting together
30%
Failed cylinder #2 fuel injector with internal coil short
20%
Corroded or contaminated injector connector at cylinder #2
15%
ECM cylinder #2 injector driver circuit failure
Diagnostic Steps
1
Check for misfire codes on cylinder #2 (P0302) and any other injector circuit codes to determine if the issue is isolated.
2
Disconnect the cylinder #2 injector connector and inspect for corrosion, melted plastic, or contamination between the pin cavities.
3
Measure the injector coil resistance across the two terminals — it should be within manufacturer specification (typically 11-18 ohms for high-impedance). Check for shorts to the injector body as well.
4
With the injector disconnected, use a multimeter to verify no continuity exists between the two harness-side wires at the connector — continuity here indicates a harness short.
5
Swap the cylinder #2 injector with an adjacent cylinder's injector. If the code follows the injector, replace it. If the code stays on cylinder #2, the wiring or ECM driver is at fault.
Estimated Repair Cost
$100 - $500
Parts + labor, varies by vehicle and location
The ECM has detected a high-to-low side short circuit in the cylinder #2 fuel injector driver circuit. The high-side power and low-side control wires for cylinder #2's injector are making unintended electrical contact, which can result in uncontrolled injector operation or a complete misfire on that...
The most common cause of P1262 (Cylinder #2 High To Low Side Short) is: Chafed or heat-damaged injector wiring harness with high and low side wires shorting together
Typical repair costs for P1262 range from $100 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A shorted injector driver can cause persistent misfires leading to loss of power, rough idle, and potential catalytic converter damage from unburned fuel. An uncontrolled injector can also cause cylinder wash and accelerated engine wear. Risk of ECM driver damage if the short persists.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1262 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel Injection System
Difficulty
Type
Manufacturer
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