DEF Dosing Valve Circuit High (Generic)
The P4062 code means the vehicle's onboard diagnostic system has detected: DEF Dosing Valve Circuit High (Generic). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $200 - $700 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Excessive DEF injection
- DEF consumption abnormally high
- White deposits in exhaust tip
- DEF tank depleting rapidly
Probable Causes (Ranked by Likelihood)
- Short to voltage in dosing valve circuit Very High
- Dosing valve stuck open High
- Wiring damage causing high signal Moderate
- PCM commanding incorrect dose Low
Step-by-Step Diagnostic Procedure
-
Check dosing valve signal voltage
-
Disconnect valve and check for stray voltage
-
Inspect for stuck-open valve condition
-
Review DEF injection commanded vs actual values
Frequently Asked Questions
Can too much DEF damage the SCR?
Excess DEF can cause ammonia slip, producing a strong smell from the exhaust.
Why is my DEF consumption so high?
If the dosing valve is stuck open, DEF consumption can be 2-5 times normal.
Can I drive with P4062?
You can drive short distances but DEF consumption will be excessive.
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