What is Ashok Leyland P0672?
P0672 specifically indicates a fault in the glow plug heater circuit for cylinder number 2. On Ashok Leyland engines, each cylinder has its own individual glow plug circuit monitored by the ECM. P0672 means cylinder 2 is not being properly pre-heated before startup, causing uneven combustion across the engine, misfires on that cylinder, and increased emissions. Multiple cylinder codes (P0671, P0672, P0673 etc.) together often indicate a failed glow plug control module.
Symptoms of P0672 on Ashok Leyland
Engine runs unevenly on cold start with a noticeable miss on one cylinder.
Unburnt fuel from cylinder 2 contributes to white exhaust smoke.
Rough, lumpy idle that smooths out as engine warms up — classic sign of one cold cylinder.
MIL / warning lamp illuminates as soon as this fault is detected by the ECM.
ECM restricts vehicle speed and power output to protect engine components.
ECM uses default fuel maps when sensor data is unreliable, causing over-fuelling.
What Causes P0672 on Ashok Leyland?
The individual glow plug for cylinder 2 has burnt out — requires replacement.
If multiple cylinder codes appear together, the control module has likely failed.
Corroded or loose sensor connectors cause intermittent fault codes and misdiagnosis.
Outdated or corrupted ECM firmware can trigger false fault codes. Fixed with ECM reflash.