LB7 Duramax Diagnostics

GM Silverado/Sierra 2500HD/3500, 2001-2004 — the first Duramax: CP3 common rail, LB7 injectors (a known weak point), fixed-geometry turbo, glow plugs, and no emissions system. Injector, fuel-pressure and glow-plug codes.

P0087 — Fuel Rail/System Pressure Too Low (LB7 Duramax) Measured fuel rail pressure is below the PCM's commanded value. On the LB7 Duramax this is a CP3 common-rail pressure control issue.
P0088 — Fuel Rail/System Pressure Too High (LB7 Duramax) Measured fuel rail pressure exceeds the commanded value on the LB7 Duramax CP3 common-rail system.
P0089 — Fuel Pressure Regulator Performance (LB7 Duramax) The engine control module has detected that the fuel pressure regulator is not maintaining fuel pressure within the expected range.
P0128 — Coolant Thermostat Below Regulating Temperature (LB7 Duramax) Engine coolant does not reach the expected operating temperature in the expected time.
P0182 — Fuel Temperature Sensor A Circuit Low (LB7 Duramax) Diagnostic reference for LB7 Duramax 2001-2004. P0182 is not applicable to this platform because the LB7 has no fuel temperature sensor and the ECM does not…
P0192 — Fuel Rail Pressure Sensor Circuit Low Input (LB7 Duramax) The ECM sees the fuel rail pressure sensor signal voltage lower than expected on the LB7 Duramax.
P0193 — Fuel Rail Pressure Sensor A Circuit High (LB7 Duramax) Diagnostic reference for LB7 Duramax (2001-2004) P0193. Rank causes most-likely first.
P0201 — Injector Circuit/Open - Cylinder 1 (LB7 Duramax) P0201 indicates the ECM has detected an electrical fault in the fuel injector circuit for cylinder 1 on the LB7 Duramax.
P0202 — Injector Circuit Malfunction Cylinder 2 (LB7 Duramax) P0202 on the LB7 Duramax means the ECM has detected an electrical fault in the fuel injector circuit for cylinder 2. The LB7 uses Bosch injectors mounted under…
P0203 — Injector Circuit/Open - Cylinder 3 (LB7 Duramax) P0203 on the LB7 Duramax means the ECM has detected an electrical fault in the injector circuit for cylinder 3. The LB7 uses Bosch injectors mounted under the…
P0204 — Injector Circuit/Open Cylinder 4 (LB7 Duramax) P0204 indicates the ECM has detected an electrical fault in the fuel injector circuit for cylinder 4 on the LB7 Duramax.
P0234 — Turbocharger/Supercharger Overboost Condition (LB7 Duramax) P0234 is set when the ECM detects boost pressure above the calibrated maximum for current operating conditions on the LB7 Duramax. The LB7 uses an IHI…
P0237 — Turbocharger/Supercharger Boost Sensor A Circuit Low (LB7 Duramax) Diagnostic reference for P0237 on LB7 Duramax (2001–2004).
P0299 — Turbocharger/Supercharger Underboost Condition (LB7 Duramax) Diagnostic reference for LB7 Duramax (2001-2004) P0299. Rank causes most-likely first.
P0300 — Random/Multiple Cylinder Misfire Detected (LB7 Duramax) Diagnostic reference for P0300 on LB7 Duramax (2001–2004).
P0335 — Crankshaft Position Sensor A Circuit Malfunction (LB7 Duramax) Diagnostic reference for LB7 Duramax (2001–2004) P0335.
P0341 — Camshaft Position Sensor A Circuit Range/Performance (LB7 Duramax) Diagnostic reference for LB7 Duramax (2001-2004) P0341. Rank causes most-likely first.
P0380 — Glow Plug/Heater Circuit Malfunction (LB7 Duramax) P0380 on the LB7 Duramax means the ECM has detected an electrical fault in the glow plug heater circuit. The LB7 uses eight glow plugs controlled by a glow…
P0670 — Glow Plug Control Module Circuit (LB7 Duramax) The PCM has detected a fault in the glow-plug control module circuit on the LB7 Duramax. This is a cold-start system fault; the Duramax uses glow plugs with a…
P1093 — Fuel Pressure Regulator Control Circuit Low (LB7 Duramax) P1093 is a manufacturer-specific low rail pressure during power enrichment code for the LB7 Duramax (2001–2004) with Bosch CP3 pump, rail pressure sensor, and…
P1216 — Injection Timing Control Circuit Range/Performance (LB7 Duramax) P1216 is a generic OBD-II code for injection timing control circuit range/performance. On the LB7 Duramax 2001-2004 this DTC is not a defined code for the…