Injector Circuit Malfunction - Cylinder 2
The P0202 code indicates a problem in the electrical circuit of the fuel injector for cylinder 2. This could be due to an open or short circuit in the wiring, a faulty injector, or a problem with the engine control module (ECM). The injector circuit includes the injector itself, the wiring harness, connectors, and the ECM driver. When the ECM detects an abnormal voltage or resistance in the circuit, it sets this code. This can cause the cylinder to misfire, leading to poor engine performance, increased emissions, and potential damage to the catalytic converter if left unresolved.
1. Most Common Causes
- Faulty fuel injector on cylinder 2 with an open coil, internal short, or out-of-spec resistance
- Open circuit, short to ground (B-), or short to battery voltage (B+) in the injector circuit wiring or connectors
- Poor electrical connection, corroded, bent, or loose pins at the injector connector or harness splices
- Failed injector driver (controller) inside the PCM/ECM
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine misfire or rough idle
- Reduced engine power and acceleration
- Increased fuel consumption and emissions
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect injector wiring and connector for damage or corrosion.
Step 3: Measure injector resistance with a multimeter (should be 11-18 ohms).
Step 4: Check for power and ground at injector connector with key on.
Step 5: Swap injector with another cylinder to see if code moves.
Step 6: Test ECM output with a noid light or oscilloscope.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause misfire, damage the catalytic converter, and reduce fuel economy. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on whether the injector needs replacement or just wiring repair.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.