LLY / LBZ / LMM Duramax Diagnostics
GM Silverado/Sierra 2500HD/3500, 2004.5-2010 — the middle Duramax era: CP3 common rail, first variable-geometry turbo, EGR from the LLY, and a DPF on the LMM (2007.5+). Injector, VGT, EGR and (LMM) DPF codes.
- P003A — Turbocharger Boost Control Position Sensor/Switch Circuit Range/Performance (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010. P003A indicates the ECM has detected the VGT boost control position sensor/switch signal is outside…
- P0045 — Turbocharger Boost Control Solenoid A Circuit/Open (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010. P0045 indicates the PCM has detected an electrical fault in the turbocharger boost control solenoid A…
- P0087 — Fuel Rail/System Pressure Too Low (LLY / LBZ / LMM Duramax) Measured fuel rail pressure is below the PCM's commanded value on LLY/LBZ/LMM Duramax 2004.5–2010 with Bosch CP3 common rail and pump-mounted fuel pressure…
- P0088 — Fuel Rail/System Pressure Too High (LLY / LBZ / LMM Duramax) Fuel Rail/System Pressure Too High
- P0089 — Fuel Pressure Regulator Performance (LLY / LBZ / LMM Duramax) P0089 on LLY/LBZ/LMM Duramax means the ECM has detected the fuel pressure regulator is not maintaining rail pressure within the expected range on the CP3…
- P0101 — Mass or Volume Air Flow Circuit Range/Performance (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010.
- P0128 — Coolant Thermostat Below Regulating Temperature (LLY / LBZ / LMM Duramax) P0128 on LLY/LBZ/LMM Duramax means the PCM has not seen the engine reach the expected coolant temperature within the expected time. The platform uses a…
- P0193 — Fuel Rail Pressure Sensor A Circuit High (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010.
- P0201 — Injector Circuit/Open - Cylinder 1 (LLY / LBZ / LMM Duramax) P0201 is an electrical fault detected by the ECM in the fuel injector circuit for cylinder 1 on LLY/LBZ/LMM Duramax 2004.5–2010. The code is generic SAE J2012…
- P0202 — Injector Circuit Malfunction Cylinder 2 (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010. P0202 indicates the ECM has detected an electrical fault in the fuel injector circuit for cylinder 2.
- P0234 — Turbocharger/Supercharger Overboost Condition (LLY / LBZ / LMM Duramax) P0234 is set when the ECM detects boost pressure above the calibrated maximum for current operating conditions on the LLY/LBZ/LMM Duramax VGT turbo.
- P0299 — Turbocharger/Supercharger Underboost Condition (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010.
- P0300 — Random/Multiple Cylinder Misfire Detected (LLY / LBZ / LMM Duramax) Random/Multiple Cylinder Misfire Detected
- P0380 — Glow Plug/Heater Circuit Malfunction (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010.
- P0401 — Exhaust Gas Recirculation Flow Insufficient (LLY / LBZ / LMM Duramax) Exhaust Gas Recirculation Flow Insufficient
- P0402 — Exhaust Gas Recirculation Flow Excessive (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010. Diagnose, do not give step-by-step repair of safety-critical systems.
- P0404 — Exhaust Gas Recirculation Control Circuit Range/Performance (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010. EGR present on all; DPF only on LMM; no SCR/DEF on any. Code indicates EGR control circuit operating…
- P0420 — Catalyst System Efficiency Below Threshold (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010. P0420 is a generic OBD-II catalyst efficiency code. On this platform the ECM does not run a…
- P0670 — Glow Plug Control Module Circuit (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax (2004.5–2010) P0670. Rank causes most-likely first.
- P2002 — Diesel Particulate Filter Efficiency Below Threshold (Bank 1) (LLY / LBZ / LMM Duramax) Diagnostic reference for LLY/LBZ/LMM Duramax 2004.5–2010. DPF codes apply to LMM only; LLY/LBZ have no DPF hardware.
- P2452 — Diesel Particulate Filter Pressure Sensor A Circuit (LLY / LBZ / LMM Duramax) P2452 is a generic OBD-II code for a DPF differential-pressure sensor circuit fault. On the 2004.5–2010 6.6L Duramax family, DPF hardware exists only on the…
- P2459 — Diesel Particulate Filter Regeneration Frequency (LLY / LBZ / LMM Duramax) P2459 indicates the ECM has counted DPF regenerations more often than expected. On the LLY/LBZ/LMM family this code only applies to the LMM (2007.5–2010) which…
- P2563 — Turbocharger Boost Control Position Sensor Circuit High (LLY / LBZ / LMM Duramax) P2563 on LLY/LBZ/LMM Duramax means the ECM is seeing higher-than-expected voltage on the VGT turbocharger boost control position sensor circuit. The VGT uses…
- P2564 — Turbocharger Boost Control Position Sensor Circuit Low (LLY / LBZ / LMM Duramax) P2564 on LLY/LBZ/LMM Duramax means the ECM is seeing an abnormally low voltage from the VGT turbocharger boost control position sensor circuit. The VGT on…