Diagnostics and testing 2.7L (Discovery 3)

Inspection and verification

1. Ensure that the customer's complaint is justified.

2. Visually inspect for obvious mechanical and electrical problems.

Mechanical factors	Electrical factors
Coolant leaks Coolant hoses Coolant expansion tank Radiator Heater radiator Auxiliary drive belt Fan with viscous coupling	Fuses and fuses Wiring harnesses Loosening or corrosion of connector(s) Coolant Temperature (ECT) Sensor

3. If an obvious cause for the problem you identified or the customer described is found, resolve it before moving on to further action. (if possible).

4. Use the approved diagnostic system or scan tool to retrieve all diagnostic trouble codes (DTCs) before referring to the symptom chart or DTC index.

Clear all DTCs after troubleshooting.

Table of signs of malfunction

Sign of malfunction	Possible reason	Actions
Loss of coolant	Hoses Hose connections Radiator Coolant pump Heater radiator Gaskets Cracks in engine castings Cylinder Block Rod Plugs	Perform a visual inspection. If there are no obvious leaks, perform a pressure test using service station equipment. Repair if necessary. Refer to the appropriate section in the service station manual.
Overheat	Low coolant level/contaminated Thermostat Fan with viscous coupling ECT sensor Obstructions to air flow through the radiator	Check the coolant level and condition. Check the thermostat and make any necessary repairs. Perform a pressure test of the cooling system. Refer to the relevant section in the workshop manual. Check the operation of the viscous fan, make sure that the viscous fan rotates freely. Check for obstructions to the air flow through the radiator.
The engine does not reach normal temperature	Thermostat Fan with viscous coupling Thermostat Electric fan Fan speed module	Check the operation of the thermostat. Check the operation of the fan with viscous coupling, make sure that the fan with viscous coupling does not stick.

The article was copied from the website (www.LRman.ru)

DTC Index

DTC codes	Description	Possible reasons	Actions
P011600	Engine Coolant Temperature Sensor 1 Circuit Range/Performance Problem	Coolant Temperature (ECT) Sensor Circuit High Resistance ECT Sensor Circuit Short to Ground ACT sensor electrical circuit: short circuit to battery + ECT sensor failure	Check the ECT sensor and electrical circuits. Refer to the electrical manuals. With the engine cold, read the coolant temperature sensor value using the data logger function and start the engine. Record the value and let the engine idle for 20 minutes. Check the value again after 20 minutes. If the value has not increased by more than 10°C, install a new sensor. Refer to the appropriate section in the workshop manual. Clear the DTCs and check for proper operation.
P011700	Engine Coolant Temperature (ECT) Sensor 1 Circuit Low Voltage	ECT sensor disconnected ECT Sensor Sensing Circuit: High Resistance, Short to Battery + ECT sensor failure	Refer to the guided diagnostic program for this code on the approved diagnostic system.
P011800	Engine Coolant Temperature (ECT) Sensor 1 Circuit High Voltage	Engine overheating condition/cooling fan malfunction ECT Sensor Wiring: Short to Ground ECT sensor failure	Check the coolant level and thermostat operation. (stuck in closed position). Check for cooling fan DTCs. Refer to the guided diagnostic routine for this code on the approved diagnostic system.
P011900	Intermittent/erratic signal in the electrical circuit of the engine coolant temperature sensor 1	Coolant Temperature (ECT) Sensor Circuit High Resistance ECT Sensor Circuit Short to Ground ECT sensor electrical circuit: short circuit to battery + ECT sensor failure	Check the ECT sensor and electrical circuits. Refer to the electrical manuals. With the engine cold, read the coolant temperature sensor value using the data logger function and start the engine. Record the value and let the engine idle for 20 minutes. Check the value again after 20 minutes. If the value has not increased by more than 10°C, install a new sensor. Refer to the appropriate section in the workshop manual. Clear the DTCs and check for proper operation.