What Does P1145 Mean?
This code indicates an electrical fault in the solenoid valve that controls the running losses evaporative emission system. This solenoid is part of the EVAP system and manages fuel vapor flow during engine operation to prevent hydrocarbon emissions from escaping to the atmosphere. The ECM has detected an open, short, or out-of-range condition in the solenoid's control circuit.
Common Causes
30%
Failed running losses solenoid valve (internal open or short)
25%
Open or shorted wiring in the solenoid control circuit
20%
Corroded or disconnected connector at the solenoid valve
15%
Blown fuse in the EVAP solenoid power supply circuit
10%
ECM driver circuit failure for the running losses solenoid output
Diagnostic Steps
1
Locate the running losses solenoid valve and inspect the electrical connector for corrosion, damage, or disconnection.
2
Measure the solenoid coil resistance with a multimeter (typically 20-40 ohms); infinite resistance indicates an open coil, very low resistance indicates a short.
3
Verify the solenoid receives battery voltage on the power side and that the ECM can ground the control side.
4
Check the EVAP system fuse for continuity.
5
Command the solenoid on and off with a scan tool while listening for an audible click to confirm mechanical operation.
6
Inspect the wiring harness between the ECM and solenoid for damage, especially near heat sources.
Estimated Repair Cost
$75 - $300
Parts + labor, varies by vehicle and location
This code indicates an electrical fault in the solenoid valve that controls the running losses evaporative emission system. This solenoid is part of the EVAP system and manages fuel vapor flow during engine operation to prevent hydrocarbon emissions from escaping to the atmosphere. The ECM has detec...
The most common cause of P1145 (Solenoid Valve Running Losses Control Circuit Electrical) is: Failed running losses solenoid valve (internal open or short)
Typical repair costs for P1145 range from $75 to $300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No safety hazard. The running losses solenoid is part of the evaporative emissions system. Failure does not affect engine performance or drivability but will cause the vehicle to fail emissions testing.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1145 to identify the root cause.
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Quick Info
Category
Powertrain
System
EVAP / Emissions Control
Difficulty
Type
Manufacturer
Recommended Tools
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