Fuel Pressure Regulator 2 Exceeded Control Limits - Pressure Too High
The P229B code indicates that the Engine Control Module (ECM) has detected that the fuel pressure regulator 2 (often associated with the high-pressure fuel system on diesel or direct injection gasoline engines) is unable to control fuel pressure within the specified range, resulting in pressure that is too high. This can be caused by a faulty fuel pressure regulator, a stuck high-pressure fuel pump, a clogged fuel return line, or a wiring issue. High fuel pressure can lead to rich fuel mixture, reduced fuel economy, and potential engine damage.
01. Most Common Causes
- Faulty fuel pressure regulator 2
- Stuck high-pressure fuel pump
- Clogged fuel return line
- Wiring or connector issues to the regulator
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor fuel economy
- Black smoke from exhaust (rich mixture)
- Engine running rough or misfiring
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to verify the code and check fuel pressure readings.
Step 2: Inspect wiring and connectors to the fuel pressure regulator for damage or corrosion.
Step 3: Test the fuel pressure regulator operation using a multimeter or manufacturer-specific test.
Step 4: Check for restrictions in the fuel return line.
Step 5: If necessary, replace the fuel pressure regulator or high-pressure fuel pump.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as high fuel pressure can cause engine damage, poor performance, and increased emissions. Have the vehicle inspected as soon as possible.
How much does it cost to fix?▼
The cost to fix P229B typically ranges from $50 to $150 for diagnosis and replacement of the fuel pressure regulator, but can be higher if the high-pressure fuel pump needs replacement.