If your Land Rover Td5 engine turns over smoothly on the starter motor but completely refuses to fire up, cuts out unexpectedly when hot, or drops its RPM signal entirely on a diagnostic tool, you are likely dealing with a crankshaft position sensor fault.

The crankshaft position sensor—also referred to as the engine speed sensor—provides the absolute timeline data that the Td5 electronic control unit (ECU) requires to pulse the electronic unit injectors. Without a crisp, uninterrupted signal from this unit, the ECU cannot determine when to deliver fuel, leaving you with a dead vehicle.

Common Td5 Crank Sensor Symptoms

Because the crank sensor signal is a pass/fail requirement for engine ignition, failure modes present themselves very distinctively:

  • Crank but No-Start: The starter motor spins the engine at healthy RPMs, but the vehicle refuses to fire or catch.
  • Intermittent Hot Cutting Out: The vehicle starts cleanly when cold but abruptly dies once it reaches full operating temperature. It often refuses to restart until the engine block has completely cooled down.
  • Loss of RPM Signal on Diagnostics: If you monitor live cranking data via a Nanocom or similar diagnostic tool, the engine speed parameter will sit stubbornly at zero.

Td5 Crank Sensor Location

The physical location of the Td5 crank sensor often catches owners out when they are attempting a fast driveway repair. It is positioned low down on the rear left-hand side of the engine block, near the flywheel housing/gearbox mating face and tucked just behind the starter motor area. Because it sits down in the path of road grime, clutch dust, and intense engine heat, environmental degradation of the unit is common over time.

Is It the Sensor or the Wiring?

Before buying replacement parts, it is highly critical to establish whether the physical sensor has failed or if the engine wiring loom itself has degraded. Due to its position, repeated heat cycles and engine rock frequently cause the sensor end of the wiring harness to become extremely brittle, cracked, or thoroughly contaminated with leaked engine oil. This mimics sensor failure exactly.

  • If the connector plug or loom wires are broken or oil-soaked: Bypassing the damaged section with a dedicated wiring overlay harness is required to restore an uninterrupted signal back to the ECU.
  • If the internal sensor coil has broken down: You require a replacement physical sensor unit.

Recommended Replacements & Fixes

To keep your vehicle reliable and prevent roadside strandings, avoid low-grade unbranded pattern alternatives. Choose the exact component setup that matches your diagnosis:

→ Buy the Genuine Lucas Td5 Crank Sensor (NSC100790G) Here
The preferred original equipment manufacturer choice when you do not want to risk a non-start fault. Supplied with the correct rubber O-ring seal.

→ Buy the Aftermarket Td5 Crank Sensor (NSC100790A) Here
A dependable standard replacement alternative if you require a lower-cost route to resolve a confirmed sensor failure.