What Does P1348 Mean?
P1348 indicates an open circuit condition in the ignition coil power output stage 1. The ECU driver transistor is attempting to control coil 1 but detects no load on the circuit, meaning the electrical path is broken somewhere between the ECU and the coil. This results in a dead misfire on the cylinder served by coil 1 since no primary current can flow.
Safety Warning
An open coil circuit causes a complete misfire on the affected cylinder, resulting in rough running, power loss, and potential catalytic converter damage from unburned fuel. Repair promptly.
Common Causes
30%
Disconnected or unseated ignition coil 1 connector
25%
Broken wire in the coil 1 control harness
25%
Failed ignition coil 1 with open primary winding
12%
Corroded or spread connector terminals at coil 1
8%
ECU coil driver output pin damaged or pushed back
Diagnostic Steps
1
Verify that ignition coil 1 connector is fully seated and locked. Push on the connector and listen for a click.
2
Disconnect coil 1 and measure primary winding resistance. An open (infinite resistance) reading confirms internal coil failure.
3
If the coil tests good, perform a continuity check on the control wire from the coil connector to the ECU connector pin.
4
Inspect both the coil-side and ECU-side connector terminals for corrosion, spread pins, or pushed-back terminals that prevent contact.
5
Check for any harness damage along the routing path, particularly at connectors, grommets, and tie-down points where wire breaks commonly occur.
Estimated Repair Cost
$50 - $300
Parts + labor, varies by vehicle and location
P1348 indicates an open circuit condition in the ignition coil power output stage 1. The ECU driver transistor is attempting to control coil 1 but detects no load on the circuit, meaning the electrical path is broken somewhere between the ECU and the coil. This results in a dead misfire on the cylin...
The most common cause of P1348 (Ignition Coil Power Output Stage 1 Open Circuit) is: Disconnected or unseated ignition coil 1 connector
Typical repair costs for P1348 range from $50 to $300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
An open coil circuit causes a complete misfire on the affected cylinder, resulting in rough running, power loss, and potential catalytic converter damage from unburned fuel. Repair promptly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1348 to identify the root cause.
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Powertrain
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Ignition System
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