Diesel Trouble Codes

P0202 — Injector Circuit Malfunction Cylinder 2 (5.9 Cummins Common Rail)

P0202 on 5.9 Cummins Common Rail 2003-2007 means the ECM detected an electrical fault in the fuel injector circuit for cylinder 2. Injectors are Bosch…

Updated September 2, 2026

What it means

The ECM has detected an electrical fault in the fuel injector circuit for cylinder number two. On this platform the 5.9L Cummins Common Rail 2003-2007 ISB uses Bosch common-rail solenoid injectors; electrical faults show as P0201-P0206; contribution/balance as P0263-family. No EGR/DPF/SCR/DEF, no VGT, grid heater not glow plugs, CP3 pump with FCA/MPROP and rail pressure sensor/relief valve.1

Most likely causes

  1. Open or short in injector 2 wiring harness / connector corrosion — Inspect injector 2 connector and harness for chafing, oil intrusion, or corrosion; check continuity to ECM. Typical on this platform: 5.9L Cummins Common Rail 2003-2007 ISB. Injectors are Bosch common-rail solenoid type; electrical faults show as P0201-P0206; contribution/balance as P0263-family.1234
  2. Faulty injector 2 solenoid / internal open — Solenoid coil resistance out of spec indicates injector electrical failure. Typical on this platform: 5.9L Cummins Common Rail 2003-2007 ISB. Injectors are Bosch common-rail solenoid type; electrical faults show as P0201-P0206; contribution/balance as P0263-family.1234
  3. ECM driver fault for cylinder 2 injector circuit — If wiring and injector test good, ECM internal driver may be suspect. Generic definition: The engine control module has detected an electrical fault in the fuel injector circuit for cylinder number two.1
  4. Intermittent connection causing misfire/jerking — NHTSA report of 2003 Dodge Ram 3500 jerking at 55 mph with no diagnosis determined; approximate failure mileage 130,000.5
  5. Related electrical issues from recalls affecting drivability — Owner reports recalls 13V-528 and 09E-001 relating to these issues with inspection but no repair.6

How to diagnose

  1. Verify code P0202 present and freeze frame data; confirm platform is 5.9 Cummins Common Rail 2003-2007.
  2. Visually inspect injector 2 connector, harness routing, and ECM harness for chafing/corrosion; check for oil in connector.
  3. Measure injector 2 solenoid resistance per spec and compare to other cylinders; inspect connector pin tension.
  4. Perform continuity and isolation tests from injector 2 connector to ECM pins; check for shorts to ground or power.
  5. If wiring and injector pass, evaluate ECM injector driver output with scan tool bi-directional control or scope; confirm fault follows injector swap.
  6. Clear codes, road test, and re-check for recurrence; monitor related codes P0201-P0206. Contribution/balance codes P0263-family indicate mechanical/performance issues, not circuit faults.

Parts and tools you may need

Rough cost and difficulty

Electrical diagnosis labor varies; injector replacement cost depends on part source and labor. Wiring repair cost depends on extent of harness damage. ECM replacement is high cost and should be confirmed before replacement.

When to see a pro

If wiring tests good and injector resistance is normal but code persists, have a qualified diesel technician evaluate ECM driver output. Do not attempt high-pressure fuel system disassembly. If drivability symptoms like sudden jerking occur, have vehicle inspected promptly for safety.

Sources

  1. Curated DTC seed — 5.9 Cummins Common Rail (curated) ↩︎ ↩︎ ↩︎ ↩︎

  2. Curated DTC seed — 5.9 Cummins Common Rail (curated) ↩︎ ↩︎

  3. Curated DTC seed — 5.9 Cummins Common Rail (curated) ↩︎ ↩︎

  4. Curated DTC seed — 5.9 Cummins Common Rail (curated) ↩︎ ↩︎

  5. NHTSA owner report 10561667 ↩︎

  6. NHTSA owner report 10744708 ↩︎