Fuel Pump Secondary Circuit Intermittent
The P0233 code indicates an intermittent fault in the secondary circuit of the fuel pump. This circuit typically includes the fuel pump relay, wiring, connectors, and the fuel pump itself. An intermittent signal suggests a loose connection, corroded terminal, or failing component that works sporadically, leading to inconsistent fuel delivery and potential drivability issues.
1. Most Common Causes
- Faulty fuel pump relay with corroded contacts
- Loose or corroded connections in the fuel pump secondary circuit
- Damaged, chafed, or moisture-contaminated wiring in the fuel pump harness
- Defective fuel pump control module (FPCM)
- Intermittent internal failure of the fuel pump
- Loose or oxidized pins at the fuel pump connector
- Poor ground in the control circuit
2. Symptoms You Will Notice
- Intermittent engine stalling or hesitation
- Hard starting or no-start condition
- Check Engine Light illuminated
- Reduced fuel economy
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect fuel pump relay, fuse, and wiring for damage or corrosion.
Step 3: Test fuel pump relay operation using a multimeter or scan tool.
Step 4: Check fuel pump voltage and ground at the pump connector while wiggling harness to reproduce intermittent fault.
Step 5: Perform a fuel pressure test to confirm pump output.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. An intermittent fuel pump can cause sudden stalling, leading to loss of power steering and brakes, increasing accident risk.
How much does it cost to fix?▼
The cost ranges from $50 to $150 for diagnosis and minor repairs like relay or wiring fixes. Fuel pump replacement can cost $400-$800.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.