What Does P2048 Mean?
The DEF injector circuit voltage is lower than expected during operation. This indicates a short to ground, high resistance, or excessive current draw in the injector circuit.
Common Causes
35%
DEF injector internal short to ground or partial coil failure
30%
Wiring harness chafed or shorted to ground between ECM and injector
20%
Corroded injector connector causing high resistance or ground path
10%
Water contamination in DEF causing injector coil damage
5%
ECM driver circuit malfunction providing insufficient voltage
Diagnostic Steps
1
Step 1: Disconnect DEF injector and measure resistance - compare to specifications
2
Step 2: Check for short to ground in injector wiring with injector disconnected
3
Step 3: Inspect wiring harness for damage, particularly where it routes near sharp edges or heat sources
4
Step 4: Test voltage supply to injector connector with key on - should match battery voltage
5
Step 5: Monitor injector current draw during operation if tools available
Estimated Repair Cost
$200 - $850
Parts + labor, varies by vehicle and location
The DEF injector circuit voltage is lower than expected during operation. This indicates a short to ground, high resistance, or excessive current draw in the injector circuit.
The most common cause of P2048 (Reductant Injection Valve Circuit Low Bank 1 Unit 1) is: DEF injector internal short to ground or partial coil failure
Typical repair costs for P2048 range from $200 to $850, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive but SCR system effectiveness is compromised. May lead to engine derate and increased NOx emissions if not repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2048 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control - SCR System
Difficulty
Type
Generic (SAE)
Recommended Tools
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