Diagnosis and check 4.4L (Discovery 3)

Inspection and verification

1. Accurately identify the problem indicated by the customer.

2. Visually inspect for obvious mechanical and electrical problems.

Mechanical elements	Electrical elements
Fuel leaks Damaged fuel lines Damaged fittings Fuel level Fuel contamination/fuel brand/fuel quality throttle body Damaged fuel filler cap Damaged fuel filler pipe	Fuses Inertial switch Loose or corroded electrical connectors Wiring harnesses Sensor (And) Engine control module (ECM)

3. If an obvious cause for a customer-specified or customer-reported issue is identified, correct the issue before proceeding to the next step (if possible).

4. Read all DTCs before referring to the symptom table or DTC index (DTC) using an approved diagnostic system or scan tool.

Clear all DTCs after troubleshooting.

Trouble symptom table

Symptom	Possible reasons	Action taken
The engine crankshaft rotates, but the engine does not start	Low/contaminated fuel Ignition system Fuel system crankshaft position sensor (CKP) Wiring harness ECM malfunction	Check the level and condition of the fuel. Ignition system checks are described in the appropriate section of the workshop manual. Check for injector related DTCs. For testing CKP and wiring harness. Refer to the relevant section in the workshop manual. If there is any doubt about the functionality of the module, refer to the Warranty Policy and Procedures Manual.
The crankshaft of the engine scrolls, there are flashes, but the engine does not start	EVAP canister purge valve Fuel system Spark plug Malfunction (And) ignition coils	Purge valve checks are described in the appropriate section of the workshop manual. Check for injector related DTCs. Ignition system checks are described in the appropriate section of the workshop manual.
Cold start difficulties	Check the content of antifreeze in the cooling system Accumulator battery crankshaft position sensor (CKP) Jamming in the open position of the exhaust gas recirculation valve (EGR) Fuel system EVAP canister purge valve	For battery information, see the relevant section of the workshop manual. Crankshaft position sensor checks are described in the appropriate section of the workshop manual. Check for injector related DTCs. Purge valve checks are described in the appropriate section of the workshop manual.
Hot Start Difficulties	Nozzle leak Fuel system Fuel temperature sensor Intake air temperature sensor (IAT) Mass air flow sensor (MAF) EVAP canister purge valve Ignition system	Check for injector related DTCs. Checks for fuel temperature, intake air temperature and mass air flow sensors are described in the appropriate section of the workshop manual. Purge valve and ignition system checks are described in the relevant section of the workshop manual.
Difficulty starting after a hot soak (the vehicle remains stationary for a while after the engine has reached operating temperature)	Nozzle leak Fuel system Fuel temperature sensor IAT sensor MAF sensor EVAP canister purge valve Ignition system	Check for injector related DTCs. Checks for fuel temperature, intake air temperature and mass air flow sensors are described in the appropriate section of the workshop manual. Purge valve and ignition system checks are described in the relevant section of the workshop manual.
Engine stalls shortly after starting	Disconnecting/reducing the capacity of the ventilation system ECM relay MAF sensor Ignition system Clogged air filter Air leakage Fuel lines	Check engine ventilation system. Check the operation of the ECM relay. Checks for mass air flow, fuel rail pressure and ignition system sensors are described in the appropriate section of the workshop manual. For air inlet and fuel line information, see the relevant section of the workshop manual.
Engine acceleration lag/poor acceleration	Fuel pump Fuel lines Nozzle leak Fuel pressure Air leakage Throttle Position Sensors (TR) Accelerator pedal position sensor (APP) Throttle Motor Ignition system EGR valve sticking HO2 sensors Transmission malfunction Difficulty moving the pedal (flooring, etc.)	For information on the fuel pump and fuel line, see the relevant section of the workshop manual. Check for injector related DTCs. Checks for the air intake system, throttle position sensors and accelerator pedal position are described in the appropriate section of the workshop manual. Refer to the guided diagnostic program on the approved diagnostic system for throttle motor checks. Ignition system checks are described in the appropriate section of the workshop manual. Check for DTCs for HO2 sensors, refer to the DTC Index. For gearbox information, see the relevant section of the workshop manual. Check the movement of the accelerator pedal.
Backfires in the engine	Fuel pump Fuel lines Air leakage MAF sensor APP sensor HO2 sensors Ignition system	For information on the fuel pump, fuel line, and air intake system, see the relevant section of the workshop manual. Checks for mass air flow sensors and accelerator pedal position are described in the relevant section of the workshop manual. Check for DTCs for HO2 sensors, refer to the DTC Index. Ignition system checks are described in the appropriate section of the workshop manual.
Engine Jerks	Fuel pump Fuel lines MAF sensor Wiring harness TP sensors Throttle Motor Ignition system	For information on the fuel pump and fuel line, see the relevant section of the workshop manual. Checks for mass air flow and throttle position sensors are described in the relevant section of the workshop manual. Refer to the guided diagnostic program on the approved diagnostic system for throttle motor checks. Ignition system checks are described in the appropriate section of the workshop manual.
Knocking / knocking in the engine	Fuel pump Fuel lines Fuel quality Knock sensor malfunction (EC) /electrical circuit MAF sensor HO2 sensors Air leakage BARO sensor malfunction (internal ECM malfunction)	For information on the fuel pump and fuel line, see the relevant section of the workshop manual. Checks for fuel rail pressure, mass air flow and knock sensors are described in the appropriate section of the workshop manual. Check for DTCs for HO2 sensors, refer to the DTC Index. For information on the air intake system, see the relevant section of the workshop manual. If there is any doubt about the functionality of the module, refer to the Warranty Policy and Procedures Manual.
Lack of throttle response	APP sensor malfunction TP sensors Throttle Motor	Accelerator pedal position and throttle position sensor checks are described in the relevant section of the workshop manual. Refer to the guided diagnostic program on the approved diagnostic system for throttle motor checks.
Poor throttle response	APP sensor malfunction TP sensors ECT sensor MAF sensor Transmission malfunction Traction control activation Air leakage Disconnecting/reducing the capacity of the ventilation system	Checks for accelerator pedal position, throttle position, coolant temperature and mass air flow sensors are described in the appropriate section of the workshop manual. For gearbox information, see the relevant section of the workshop manual. Refer to the relevant section of the workshop manual for information on air intake system checks. Refer to the relevant section of the workshop manual for information on breather system checks.

DTC pointer

NOTE: Universal Scan Tools may not read the listed codes or may only read 5-digit codes. Match the 5 digits from the scan tool with the first 5 digits of the listed 7 digit code to identify the problem (the last 2 digits give additional information read by the approved diagnostic system).

NOTE: See Section 303-14 for a complete list of ECM DTCs "Electronic engine management system" in the workshop manual.

DTC	Description	Possible reasons	Action taken
P008700	Too low pressure in the fuel manifold / in the system	Fuel rail pressure sensor (FRP) disconnected Signal circuit from FRP sensor to ECM - short circuit to ground FRP Sensor Power Circuit High Resistance FRP Sensor Malfunction Leak in the fuel line Reducing the capacity of the fuel line Fuel pump module circuit high resistance Fuel Pump Module Circuit Short to Ground Fuel Pump Module Malfunction	Fuel rail pressure sensor checks are described in the relevant section of the workshop manual. Check fuel lines, fuel pressure, fuel pump module electrical circuits.
P008800	Too high pressure in the fuel manifold / in the system	Wiring between fuel rail pressure sensor (FRP) and ECM (power/signal): short circuit between circuits Signal circuit between FRP sensor and ECM short circuit to voltage FRP Sensor Malfunction Fuel pressure control valve malfunction (FPCV) Fuel pump module circuit short to voltage Fuel Pump Module Malfunction	Fuel rail pressure sensor checks are described in the relevant section of the workshop manual. Check fuel lines, fuel pressure, fuel pump module electrical circuits.
P017100	Too much lean in the system (cylinder bank 1)	Air intake leak between mAf sensor and cylinder head MAF sensor malfunction (low intake air flow) Reducing the capacity of the fuel filter / fuel system Low fuel pressure Reduced fuel injector capacity Leak in the exhaust system (before the catalytic converter) Evaporative Emission System Malfunction	Check the air intake system for leaks, etc. Check the fuel system for reduced capacity, DTCs, etc. Check the exhaust system for leaks, etc. Check for DTCs for the evaporative emission system.
P017200	Too much enrichment in the system (cylinder bank 1)	Reducing the capacity of the air filter High fuel pressure Fuel injector leak (Oh) Oil contamination with fuel (too many cold starts without warming up for a sufficiently long time) MAF sensor malfunction Evaporative Emission System Malfunction	Check the air intake system for reduced capacity, etc. Check the fuel system for leaks, DTCs, etc. Check the condition of the oil. Check for DTCs for the MAF sensor and the evaporative emission system.
P017400	Too much lean in the system (cylinder bank 2)	Air intake leak between MAF sensor and cylinder head MAF sensor malfunction (low intake air flow) Reducing the capacity of the fuel filter / fuel system Low fuel pressure Reduced fuel injector capacity Leak in the exhaust system (before the catalytic converter) Evaporative Emission System Malfunction	Check the air intake system for leaks, etc. Check the fuel system for reduced capacity, DTCs, etc. Check the exhaust system for leaks, etc. Check for DTCs for the evaporative emission system.
P017500	Too much enrichment in the system (cylinder bank 2)	Reducing the capacity of the air filter High fuel pressure Fuel injector leak (Oh) Oil contamination with fuel (too many cold starts without warming up for a sufficiently long time) MAF sensor malfunction Evaporative Emission System Malfunction	Check the air intake system for reduced capacity, etc. Check the fuel system for leaks, DTCs, etc. Check the condition of the oil. Check for DTCs for the MAF sensor and the evaporative emission system.
P020100	Cylinder 1 injector open circuit	Nozzle disconnected Injector harness high resistance, short to ground Injector failure	Fuel system checks are described in the relevant section of the workshop manual. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system.
P020200	Cylinder 2 injector open circuit	Nozzle disconnected Injector harness high resistance, short to ground Injector failure	Fuel system checks are described in the relevant section of the workshop manual. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system.
P020300	Cylinder 3 injector open circuit	Nozzle disconnected Injector harness high resistance, short to ground Injector failure	Fuel system checks are described in the relevant section of the workshop manual. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system.
P020400	Cylinder 4 injector open circuit	Nozzle disconnected Injector harness high resistance, short to ground Injector failure	Fuel system checks are described in the relevant section of the workshop manual. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system.
P020500	Cylinder 5 injector open circuit	Nozzle disconnected Injector harness high resistance, short to ground Injector failure	Fuel system checks are described in the relevant section of the workshop manual. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system.
P020600	Cylinder 6 injector open circuit	Nozzle disconnected Injector harness high resistance, short to ground Injector failure	Fuel system checks are described in the relevant section of the workshop manual. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system.
P020700	Cylinder 7 injector open circuit	Nozzle disconnected Injector harness high resistance, short to ground Injector failure	Fuel system checks are described in the relevant section of the workshop manual. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system.
P020800	Cylinder 8 injector open circuit	Nozzle disconnected Injector harness high resistance, short to ground Injector failure	Fuel system checks are described in the relevant section of the workshop manual. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system.
P210129	Throttle Actuator A Control Motor Circuit Range/Performance Problems	Pinched throttle, gearbox or motor	Check for fuel system related DTCs and messages on the instrument panel. Repair if necessary. If problem persists, replace throttle body. Refer to the relevant section in the workshop manual.
P210164	Throttle Actuator A Control Motor Circuit Range/Performance Problems	Pinched throttle, gearbox or motor	Check for fuel system related DTCs and messages on the instrument panel. Repair if necessary. If problem persists, replace throttle body. Refer to the relevant section in the workshop manual.
P210329	High voltage in the electric circuit of the throttle actuator control motor A	Throttle actuator control circuit short circuit to battery. ECM malfunction	Check the electrical part of the throttle body and circuits. Refer to electrical manuals. Clear DTCs and check for correct operation. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system. If an ECM is suspected, refer to the warranty policy and procedures manual.
P210364	High voltage in the electric circuit of the throttle actuator control motor A	Control circuit short circuit to battery ECM malfunction	Check the electrical part of the throttle body and circuits. Refer to electrical manuals. Clear DTCs and check for correct operation. For this code, refer to the diagnostic procedure supplied with the approved diagnostic system. If an ECM is suspected, refer to the warranty policy and procedures manual.
P210500	Throttle Motor Control System - Forced Engine Shutdown	Throttle request to turn on MIL due to fuel cut	Check for DTCs indicating the cause of the fuel cut. Follow the steps for these DTCs.
P210629	Throttle Actuator Control System - Forced Engine Power Limitation	Deliberate power reduction (emergency operation)	Check for fuel system related DTCs and messages on the instrument panel. Repair if necessary. If problem persists, replace throttle body. Refer to the relevant section in the workshop manual.
P210664	Throttle Actuator Control System - Forced Engine Power Limitation	Deliberate power reduction (emergency operation)	Check for fuel system related DTCs and messages on the instrument panel. Repair if necessary. If problem persists, replace throttle body. Refer to the relevant section in the workshop manual.
P211800	Throttle Actuator Control Motor Operating Range/Current Problems	Throttle Motor Over Current Condition Registered ECM malfunction	Check the wiring between the ECM and the throttle actuator according to the electrical manual. For this code, refer to the diagnostic procedure supplied with the code-approved diagnostic system. If an ECM malfunction is suspected, refer to the Warranty Policy and Procedures Manual.
P211900	Throttle Body Operating Range/Performance Issues in Throttle Actuator Control Aspect	Throttle spring failure	Check the throttle return spring on the throttle body. Repair/replace as needed. Check for fuel system related DTCs and messages on the instrument panel. Repair if necessary. If problem persists, replace throttle body. Refer to the relevant section in the workshop manual.