In the previous article, we covered the interpretation of codes DF083 to DF128 of the Renault Megane 2 petrol engine.
Let's continue:
DF073 Cylinder No. 2 ignition coil circuit
Fault cause: open circuit or short circuit to earth.
If faults DF046, DF084 or DF085 are present or stored, process them first.
If fault «Cylinder No. 3 ignition coil circuit» is also present or stored, process it first.
Diagnostic conditions for a stored fault:
- The fault is defined as present after 10 seconds of starter operation or after a 10-second hold with the engine running.
Disconnect the connector of the pencil-type ignition coil for cylinder No. 2.
Check the cleanliness and condition of the pencil-type coil and its connector.
Check the resistance of the primary and secondary windings of the ignition coil for cylinder No. 2 (values see «Component resistance table»).
If the values are out of specification, replace the pencil-type ignition coil.
Disconnect the battery and the injection system ECU.
Check the cleanliness of the contacts and the condition of the connector.
Connect a universal contact board in place of the ECU and check for open circuits and short circuits in the following circuit:
ECU, contact M3, connector C → Cylinder No. 2 ignition coil.
Cylinder No. 3 ignition coil → Cylinder No. 2 ignition coil (See the connector contact number in the corresponding wiring diagram).
If the fault persists, replace the faulty pencil-type ignition coil.
If the fault persists, process other faults, then proceed to conformity checking.
After clearing the fault, erase the information from the memory.
DF074 Cylinder No. 3 ignition coil circuit
Fault cause: open circuit or short circuit to earth.
Disconnect the connector of the pencil-type ignition coil for cylinder No. 3.
Check the cleanliness and condition of the pencil-type coil and its connector.
Check the resistance of the primary and secondary windings of the ignition coil for cylinder No. 3 (values see «Component resistance table»).
If the values are out of specification, replace the pencil-type ignition coil.
Disconnect the battery and the injection system ECU.
Check the cleanliness of the contacts and the condition of the connector.
Connect a universal contact board in place of the ECU and check for open circuits and short circuits in the following circuits:
Cylinder No. 3 ignition coil → Cylinder No. 2 ignition coil.
ECU, contact M3, connector C → Cylinder No. 2 ignition coil (see the connector contact numbers in the corresponding wiring diagram).
With the card inserted in the reader in the 2nd detent position, check for +12 V at the connector of the pencil-type ignition coil for cylinder No. 3 (see the connector contact number in the corresponding wiring diagram).
If +12 V is not present:
- disconnect the battery;
- disconnect in the protection and switching unit the connector marked PPM2;
- check the cleanliness of the contacts and the condition of the connector;
- connect a universal contact board. Check that the following circuit is not open:
Protection and switching unit, connector PPM1 contact 8 → Cylinder No. 3 pencil-type ignition coil.
Reconnect the protection and switching unit connector and reconnect the battery.
If, with the card in the 2nd detent position, +12 V is still not present at the cylinder No. 3 ignition coil connector, this indicates a fault in the protection and switching unit.
If the fault persists, replace the faulty pencil-type ignition coil.
If the fault persists, process other faults, then proceed to conformity checking.
After clearing the fault:
Perform the «Diagnostic conditions for a stored fault»:
- If the fault is present, continue processing the fault.
- If the fault is stored, no longer take it into account.
Process other possible faults.
Erase the fault information from the memory.
DF075 Cylinder No. 4 ignition coil circuit
Disconnect the connector of the pencil-type ignition coil for cylinder No. 4.
Check the cleanliness and condition of the pencil-type coil and its connector.
Check the resistance of the primary and secondary windings of the ignition coil for cylinder No. 4 (values see «Additional information»).
If the values are out of specification, replace the pencil-type ignition coil.
Disconnect the battery and the injection system ECU.
Check the cleanliness of the contacts and the condition of the connector.
Connect a universal contact board in place of the ECU and check for open circuits and short circuits in the following circuits:
Cylinder No. 4 ignition coil → Cylinder No. 1 ignition coil.
ECU, contact M4, connector C → Cylinder No. 1 ignition coil (see the connector contact numbers in the corresponding wiring diagram).
With the card inserted in the reader in the 2nd detent position, check for +12 V at the connector of the pencil-type ignition coil for cylinder No. 4 (see the connector contact number in the corresponding wiring diagram).
If +12 V is not present:
- disconnect the battery;
- disconnect in the protection and switching unit the connector marked PPM2;
- check the cleanliness of the contacts and the condition of the connector;
- connect a universal contact board. Check that the following circuit is not open:
Protection and switching unit, connector PPM1 contact 8 → Cylinder No. 4 pencil-type ignition coil.
Reconnect the protection and switching unit connector and reconnect the battery.
If, with the card in the 2nd detent position, +12 V is still not present at the cylinder No. 4 ignition coil connector, this indicates a fault in the protection and switching unit.
If the fault persists, replace the faulty pencil-type ignition coil.
If the fault persists, process other faults, then proceed to conformity checking.
After clearing the fault:
Perform the «Diagnostic conditions for a stored fault»:
- If the fault is present, continue processing the fault.
- If the fault is stored, no longer take it into account.
Process other possible faults.
Erase the fault information from the memory.
DF078 Motorised throttle valve control circuit
Fault cause: short circuit to +12 V; general motorised throttle valve control fault.
If faults DF095 or DF096 are present, process them first.
Diagnostic conditions for a stored fault:
The fault is defined as present after a change in engine crankshaft speed.
Air temperature must be between 5 and 105 °C.
IMPORTANT NOTE: Under no circumstances should you drive the vehicle without ensuring that all faults related to the throttle body are completely absent.
Check the cleanliness and condition of the throttle body and its connector.
Check that the throttle valve turns freely by hand.
Disconnect the battery and the injection system ECU.
Check the cleanliness of the contacts and the condition of the connector.
Connect a universal contact board in place of the ECU and check for open circuits and short circuits in the following circuits:
ECU contact M3, connector B → Motorised throttle body.
ECU contact M4, connector B → Motorised throttle body.
ECU contact G4, connector B → Motorised throttle body.
(see the connector contact numbers in the corresponding wiring diagram).
Check the electrical resistance of the throttle actuator motor by measuring at contacts M3 and M4 of the ECU connector (value see «Additional information»).
If the value is not to specification, replace the throttle body.
If the fault persists, process other faults, then proceed to conformity checking.
After clearing the fault:
If the throttle body has been replaced, perform reprogramming («RZ008»).
Perform the «Diagnostic conditions for a stored fault»:
- If the fault is present, continue processing the fault.
- If the fault is stored, no longer take it into account.
Process other possible faults. Erase the fault information from the memory.
DF079 Motorised throttle body servo system
Causes: fault in detecting throttle valve stops; error in programming the motorised throttle valve default position; throttle actuator fault; throttle valve does not set to the programmed position.
If faults DF078, DF095 or DF096 are present or stored, process them first.
Diagnostic conditions for a stored fault:
The fault is defined as present after a change in engine crankshaft speed.
Air temperature must be between 5 and 105 °C.
IMPORTANT NOTE: Under no circumstances should you drive the vehicle without ensuring that all faults related to the throttle body are completely absent.
Check the cleanliness and condition of the throttle body and its connector.
Check that the throttle valve turns freely by hand.
Disconnect the battery and the injection system ECU.
Check the cleanliness of the contacts and the condition of the connector.
Connect a universal contact board and check for open circuits and short circuits in the following circuits:
- ECU contact M3, connector B → Motorised throttle body;
- ECU contact M4, connector B → Motorised throttle body;
- ECU contact G4, connector B → Motorised throttle body;
- ECU contact G3, connector B → Throttle position sensor, track 1;
- ECU contact G2, connector B → Throttle position sensor, track 1;
- ECU contact D3, connector B → Throttle position sensor, track 2;
- ECU contact G2, connector B → Throttle position sensor, track 2.
(see the connector contact numbers in the corresponding wiring diagram).
If fault DF011 is present or stored, process this fault.
Check the resistance of the throttle actuator motor by measuring at contacts M3 and M4 (value see «Additional information»).
If the value is not to specification, replace the throttle body.
If the fault persists, process other faults, then proceed to conformity checking.
After clearing the fault:
If the throttle body has been replaced, perform reprogramming («RZ008»).
Perform the «Diagnostic conditions for a stored fault»:
- If the fault is present, continue processing the fault.
- If the fault is stored, no longer take it into account.
Process other possible faults. Erase the fault information from the memory.
DF080 Camshaft phaser solenoid valve circuit
Fault causes: open circuit; short circuit to earth; short circuit to +12 V; deviation of programmed values; inconsistency of programmed values; error in detecting phaser position; phaser control values outside tolerance.
If faults DF046 or DF084 are present or stored, process them first.
Diagnostic conditions for a stored fault:
The fault is defined as present after a change in engine crankshaft speed.
Check the cleanliness and condition of the camshaft phaser solenoid valve connections.
Check the resistance of the camshaft phaser solenoid valve (value see «Additional information»).
If the value is not to specification, replace the camshaft phaser solenoid valve.
With the card inserted in the reader in the 2nd detent position, check for +12 V at the connector of the camshaft phaser solenoid valve (see the contact number in the corresponding wiring diagram).
If +12 V is not present:
- disconnect the battery;
- disconnect in the protection and switching unit the connector marked PPM1;
- check the cleanliness of the contacts and the condition of the connector;
- connect a universal contact board. Check that the following circuit is not open:
Protection and switching unit, connector PPM1 contact 1 → Camshaft phaser solenoid valve.
Reconnect the protection and switching unit connector and reconnect the battery.
If, with the card in the 2nd detent position, +12 V is still not present at the camshaft phaser solenoid valve connector, this indicates a fault in the protection and switching unit.
Disconnect the battery.
Disconnect the ECU from the vehicle network. Check the cleanliness of the contacts and the condition of the connector.
Connect a universal contact board. Check for open circuits and short circuits in the following circuit:
ECU, contact L3, connector B → Camshaft phaser solenoid valve (see the connector contact numbers in the corresponding wiring diagram).
If the fault persists, process other faults, then proceed to conformity checking.
After clearing the fault:
Perform the «Diagnostic conditions for a stored fault»:
- If the fault is present, continue processing the fault.
- If the fault is stored, no longer take it into account.
Process other possible faults. Erase the fault information from the memory.
DF081 Canister purge solenoid valve circuit
Fault causes: open circuit; short circuit to earth; short circuit to +12 V.
If faults DF046 or DF084 are present or stored, process them first.
Diagnostic conditions for a stored fault:
The fault is defined as present after the card is inserted in the reader in the 2nd detent position.
Check the cleanliness and condition of the canister purge solenoid valve connections and its connector.
Check the resistance of the canister purge solenoid valve (value see «Additional information»).
If the resistance value is not to specification, replace the canister purge solenoid valve.
With the card inserted in the reader in the 2nd detent position, check for +12 V at the connector of the canister purge solenoid valve (see the connector contact number in the corresponding wiring diagram).
If +12 V is not present:
- disconnect the battery;
- disconnect in the protection and switching unit the connector marked PPM1;
- check the cleanliness of the contacts and the condition of the connector;
- connect a universal contact board. Check that the following circuit is not open:
Protection and switching unit, connector PPM1 contact 2 → Canister purge solenoid valve.
Reconnect the protection and switching unit connector and reconnect the battery.
If, with the card in the 2nd detent position, +12 V is still not present at the canister purge solenoid valve connector, this indicates a fault in the protection and switching unit.
Disconnect the battery.
Disconnect the ECU from the vehicle network. Check the cleanliness of the contacts and the condition of the connector.
Connect a universal contact board. Check for open circuits and short circuits in the following circuit:
ECU, contact E1, connector C → Canister purge solenoid valve (see the connector contact numbers in the corresponding wiring diagram).
If the fault persists, process other faults, then proceed to conformity checking.
After clearing the fault:
Perform the «Diagnostic conditions for a stored fault»:
- If the fault is present, continue processing the fault.
- If the fault is stored, no longer take it into account.
Process other possible faults. Erase the fault information from the memory.
DF082 Upstream oxygen sensor heater circuit
Fault causes: open circuit; short circuit to earth; short circuit to +12 V.
If faults DF046 or DF084 are present or stored, process them first.
Diagnostic conditions for a stored fault:
The fault is defined as present after a 10-second hold with the engine running.
Check the cleanliness and condition of the upstream oxygen sensor connector.
With the card inserted in the reader in the 2nd detent position, check for +12 V at the upstream oxygen sensor connector (see the connector contact number in the corresponding wiring diagram).
If +12 V is not present:
- disconnect the battery;
- disconnect in the protection and switching unit the connector marked PPM1;
- check the cleanliness of the contacts and the condition of the connector;
- connect a universal contact board and check for open circuits in the following circuit:
Protection and switching unit, connector PPM1 contact 2 → Upstream oxygen sensor.
Reconnect the protection and switching unit connector and reconnect the battery.
If, with the card in the 2nd detent position, +12 V is still not present at the upstream oxygen sensor connector, this indicates a fault in the protection and switching unit.
Disconnect the battery and the injection system ECU.
Check the cleanliness of the contacts and the condition of the connector.
Connect a universal contact board. Check for open circuits and short circuits in the following circuit:
ECU, contact L2, connector C → Upstream oxygen sensor (See the connector contact number in the corresponding wiring diagram).
Check the resistance of the upstream oxygen sensor heater element (value see «Additional information»).
If the value is not to specification, replace the upstream oxygen sensor.
If the fault persists, process other faults, then proceed to conformity checking.
After clearing the fault:
Perform the «Diagnostic conditions for a stored fault»:
- If the fault is present, continue processing the fault.
- If the fault is stored, no longer take it into account.
Process other possible faults. Erase the fault information from the memory.
