What Does P1448 Mean?
The EVAP diagnostic module detected abnormally low pump pressure during the switching phase of the leak test. This suggests a leak in the system, faulty pump, or switching valve not sealing properly during the diagnostic routine.
Common Causes
40%
EVAP system leak in hoses, connections, fuel cap, or fuel tank
25%
Faulty DM-TL switching solenoid not sealing during test
20%
Weak or failing leak detection pump unable to generate pressure
15%
Purge valve stuck open allowing pressure to escape
Diagnostic Steps
1
Step 1: Perform smoke test on EVAP system to identify any leaks in lines, connections, or tank
2
Step 2: Inspect and test fuel cap for proper seal and pressure holding capability
3
Step 3: Test purge valve for proper closure using vacuum or bidirectional scan tool controls
4
Step 4: Check switching solenoid operation and listen for clicking during actuation test
5
Step 5: Measure pump output pressure directly if accessible or replace DM-TL module if no leaks found
Estimated Repair Cost
$100 - $650
Parts + labor, varies by vehicle and location
The EVAP diagnostic module detected abnormally low pump pressure during the switching phase of the leak test. This suggests a leak in the system, faulty pump, or switching valve not sealing properly during the diagnostic routine.
The most common cause of P1448 (Diagnostic Module Tank Leakage (DM-TL) Pump Too Low During Switching) is: EVAP system leak in hoses, connections, fuel cap, or fuel tank
Typical repair costs for P1448 range from $100 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive. May cause fuel odor in some cases and will result in emissions test failure.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1448 to identify the root cause.
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Quick Info
Category
Powertrain
System
Evaporative Emissions System
Difficulty
Type
Manufacturer
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