In the previous article, we examined the decoding of codes DF001 to DF082 for the Renault Megan-2 gasoline engine
Continue:
DF083 downstream oxygen sensor heating circuit
If faults DF046 or DF084 are present or stored, deal with them first.
Requirements for diagnostics for a stored fault:
The fault is declared present after a delay of 10 seconds with the engine running.
Check the cleanliness and condition of the downstream oxygen sensor connector.
With the card installed in the reader in the 2nd fixed position, check for + 12 V at the downstream oxygen sensor connector (see the connector pin number on the corresponding wiring diagram).
If there is no +12V voltage:
- - disconnect the battery,
- - disconnect the connector marked PPM1 in the protection and switching unit,
- – check the cleanliness of the contacts and the condition of the connector,
- - Connect the universal terminal board, check the continuity of the following circuit:
Protection and switching unit, connector PPM1 pin 2 -► Downstream oxygen sensor
Connect the connector of the protection and switching unit and connect the battery.
If with the card installed in the reader in the 2nd fixed position,
Voltage + 12 V is still not supplied to the connector of the downstream oxygen sensor, this indicates a malfunction in the protection and switching unit.
Disconnect the battery and the injection computer.
Check the cleanliness of the contacts and the condition of the connector.
Connect the universal contact board. Check for open circuits and short circuits in the circuit:
ECU, pin L3, connector C -► Downstream oxygen sensor connector pin number on the relevant wiring diagram).
Check the resistance of the downstream oxygen sensor heating element
If the value is not correct, replace the downstream oxygen sensor
If the problem persists, handle other problems and then proceed to compliance.
AFTER REPAIR
Follow "Diagnostic conditions for stored fault":
- – If the fault is present, continue handling the fault.
- - If the fault is stored, don't take it into account anymore.
Treat other possible problems. Clear fault information from memory.
DF084 actuator control circuit
Disconnect the battery and the injection computer.
Check the cleanliness and condition of the ECU connections.
Disconnect the "PEM" connector in the protection and switching unit and check the cleanliness and condition of the connections.
Connect the universal contact board. Check for open circuits and short circuits in the circuit:
ECU track D4, connector B -► Protection and Switching Unit, PEM connector, pin 2 (See connector pin number on the corresponding wiring diagram).
If the fault persists, this indicates a malfunction in the protection and switching unit (the actuator relay is located in the protection and switching unit, the relay is not removable).
DF085 fuel pump relay control circuit
Cause and Effect:- Open Circuit
- - Short circuit to ground.
- - Short circuit to + 12V
Requirements for diagnostics for a stored fault:
The fault is declared present after inserting the card into the reader in the 2nd fixed position.
Disconnect the battery and the injection computer.
Check the cleanliness and condition of the ECU connections.
Disconnect the "PEM" connector in the protection and switching unit and check the cleanliness and condition of the connections.
Connect the universal terminal board. Check for open circuits and short circuits in the circuit:
ECU, pin D1, connector C -► Protection and Switching Unit, connector PEM pin 1 (See connector pin number on the corresponding wiring diagram).
If the fault persists, this indicates a fault in the protection unit and
switching (the fuel pump relay is located in the protection and switching unit, the relay is non-removable).
DF088 knock sensor circuit
Requirements for diagnostics for a stored fault:
The fault is declared present after a road test with a hot engine, at an engine speed of more than 2500 rpm.
Check the cleanliness and condition of the sensor detonation and its connector.
Check the tightness of the knock sensor.
Disconnect the battery and the injection computer.
Check the cleanliness of the contacts and the condition of the connector.
Connect the universal contact board.
Check the following circuits for open and short circuits:
- ECU channel B3, connector B -► Knock sensor
- ECU channel B4, connector B -► Knock sensor
- ECU track B2, connector B -► Knock sensor shield (see connector pin numbers on the corresponding wiring diagram).
Check the quality of the fuel in the tank.
Check the condition of the spark plugs.
If the problem persists, handle other problems and then proceed to compliance.
DF089 absolute pressure sensor circuit
The reason may be: - the voltage is out of tolerance or the signal does not match the current value
Requirements for diagnostics for a stored fault:
Fault is defined as present after:
- – transferring the card in the reader to the 1st fixed position with loss of communication,
- – setting the card to the 2nd fixed position and restoring the connection,
- – 10 second exposure while the engine is idling.
Check the cleanliness and condition of the absolute pressure sensor and its connector.
Disconnect the battery and the injection computer.
Check the cleanliness of the contacts and the condition of the connector.
Connect the universal contact board.
Check the following circuits for open and short circuits:
- ECU pin H2, connector B -► Absolute pressure sensor
- ECU pin H3, connector B -► Absolute pressure sensor
- ECU pin H4, connector B -► Absolute pressure sensor
(See the connector pin numbers on the relevant wiring diagram).
If fault DF012 is present or stored, deal with the fault.
If the problem persists, handle other problems and then proceed to compliance.
DF091 vehicle speed information
Cause and effect: - erroneous vehicle speed signal from ABS
Requirements for diagnostics for a stored fault:
The fault is declared present with the engine running.
Perform a multiplex network test.
If the problem persists, run ABS and Trajectory Stability System diagnostics.
DF092 upstream oxygen sensor circuit
Cause and effect: - open circuit, short to ground, short to +12V.
If faults DF046, DF082 or DF084 are present or stored, deal with them first.
Requirements for diagnostics for a stored fault:
The fault is declared present after: a time delay of 5 minutes while adjusting the fuel mixture (engine running).
Check the cleanliness and condition of the upstream oxygen sensor connector.
Disconnect the battery and the injection computer.
Check the cleanliness of the contacts and the condition of the connector.
- connect the universal contact board. Check for open and short circuits in the following circuits:
- ECU pin C1, connector C -► Upstream oxygen sensor
- ECU, pin B1, connector C -► Upstream oxygen sensor (see connector pin numbers on the corresponding wiring diagram).
If the problem persists, handle other problems and then proceed to compliance.
DF093 downstream oxygen sensor circuit
If faults DF084, DF046 or DF083 are present or stored, deal with them first.
Requirements for diagnostics for a stored fault:
The fault is defined as present in one of the following cases:
- - ET056 is displayed as ACTIVE when the engine cooling fan is turned on and the dual fuel mixture control loop is activated during a smooth driving road test.
- - During a smooth driving road test after the engine cooling fan is running, followed immediately by a downhill road test with the accelerator pedal released (fuel injection cuts off during engine braking).
Check the cleanliness and condition of the downstream oxygen sensor connector.
Disconnect the battery and the injection computer.
Check the cleanliness of the contacts and the condition of the connector.
Connect the universal terminal board. Check for open and short circuits in the following circuits:
- ECU, channel A2, connector C -► Downstream oxygen sensor
- ECU pin B2 connector C -► Downstream oxygen sensor (See connector pin numbers on corresponding wiring diagram).
If the problem persists, handle other problems and then proceed to compliance.
DF095 Throttle Position Sensor Gender 1 Circuit
Cause and effect: - Open circuit or short to ground, short circuit to + 12 V, signal mismatch with throttle position sensor track 1 and track 2
Requirements for diagnostics for a stored fault:
The fault is declared present after changing the engine speed.
IMPORTANT NOTICE: Never operate the vehicle until you have verified that there are no problems with the throttle body.
Check the throttle body for cleanliness and make sure the throttle turns freely (no sticking).
Check the cleanliness and condition of the throttle body connector.
Disconnect the battery and the injection computer.
Check the cleanliness of the contacts and the condition of the connector.
Connect the universal contact board. Check for open and short circuits in the following circuits:
- ECU channel G4, connector B -► Throttle position sensor, track 1
- ECU, channel G3, connector B -► Throttle position sensor, track 1
- ECU terminal G2, connector B -► Throttle position sensor, track 1
(See connector pin numbers on the corresponding wiring diagram).
If fault DF011 is present or stored, deal with the fault.
If the problem persists, handle other problems and then proceed to compliance.
DF096 Throttle Position Sensor G-2 Circuit
Cause and effect: - Short to ground, open circuit or short to +12V.
Requirements for diagnostics for a stored fault:
The fault is declared present after changing the engine speed.
IMPORTANT NOTICE: Never operate the vehicle until you have verified that there are no problems with the throttle body.
Check the throttle body for cleanliness and make sure the throttle turns freely (no sticking).
Check the cleanliness and condition of the throttle body connector.
Disconnect the battery and the injection computer.
Check the cleanliness of the contacts and the condition of the connector.
Connect the universal terminal board. Check for open and short circuits in the following circuits:
- ECU channel D3, connector B -► Throttle position sensor, track 2
- ECU terminal G2, connector B -► Throttle position sensor, track 2
- ECU, channel G4, connector B -► Throttle position sensor, conductive track 2 (see the corresponding wiring diagram for the connector pin numbers).
If fault DF011 is present or stored, deal with the fault.
If the problem persists, handle other problems and then proceed to compliance.
DF097 Camshaft Position Sensor Circuit
Cause and effect: - Camshaft sprocket tooth missing, offset measurement out of range.
If faults DF084 or DF046 are present or stored, deal with them first.
Requirements for diagnostics for a stored fault:
If the fault is determined to be present after a road test.
Check the cleanliness and condition of the camshaft position sensor connector.
Check the cleanliness and condition of the camshaft position sensor connector.
With the card installed in the reader in the 2nd fixed position, check for + 12 V on the camshaft position sensor connector (see the connector pin number on the corresponding wiring diagram).
If there is no +12V voltage:
- - disconnect the battery,
- - disconnect the connector marked "PPM1" in the protection and switching unit,
- – check the cleanliness of the contacts and the condition of the connector,
- - Connect the universal terminal board, check the continuity of the following circuit:
Protection and switching unit, connector PPM1 pin 2 -► Camshaft position sensor
Connect the connector of the protection and switching unit and connect the battery.
If with the card installed in the reader in the 2nd fixed position, the voltage is + 12 V is still not applied to the camshaft position sensor connector, this indicates a malfunction in the protection and switching unit.
Disconnect the battery.
Disconnect the computer from the on-board network. Check the cleanliness of the contacts and the condition of the connector.
Connect the universal terminal board. Check for open and short circuits in the following circuits:
- ECU, channel E2, connector C -► Camshaft position sensor
- ECU, terminal F1, connector C -► Camshaft position sensor (see connector pin numbers on the corresponding wiring diagram).
If the problem persists, then this indicates that there is most likely a malfunction of the camshaft position sensor marker.
DF099 ECU communication or ECU for manual transmission with automatic control via multiplex network
Reason: - malfunction of the connection circuit with the multiplex network
Requirements for diagnostics for a stored fault:
The fault is declared present with the engine running.
Perform a multiplex network test.
If the problem persists, diagnose the Automatic Transmission system.
DF100 multiplex communication (with instrument panel)
Reason: - malfunction of the connection circuit with the multiplex network
Perform a multiplex network test.
If the problem persists, diagnose the "Dashboard".
AFTER REPAIR
Treat other possible problems. Clear fault information from memory.
DF101 multiplex communication with trajectory stabilization system
Reason: - malfunction of the connection circuit with the multiplex network
Perform a multiplex network test.
If the problem persists, troubleshoot the ABS and Trajectory Control System.
DF105 speed limit controller on/off circuit
Reason: - inconsistency in the position of the speed limiter switch
Requirements for diagnostics for a stored fault:
The fault is declared present after a road test using first the governor and then the speed limiter.
Check the cleanliness and condition of the governor or speed limiter switch and its connections.
Check with the card installed in the reader in the 2nd fixed position, the presence of + 12 V on the connector of the governor and speed limiter switch (see the connector pin number on the corresponding wiring diagram).
Disconnect the battery.
Disconnect the computer from the on-board network. Check the cleanliness of the contacts and the condition of the connector.
Connect the universal terminal board. Check for open and short circuits in the following circuits:
- ECU, pin A2, connector A -► Governor or speed limiter switch
- ECU, track C3, connector A -► Cruise control or speed limiter switch (see corresponding wiring diagram for connector pin numbers).
If the problem persists, handle other problems and then proceed to compliance.
DF106 Steering wheel speed limiter switches
Reason: - data mismatch
Requirements for diagnostics for a stored fault:
The fault is declared present after a road test using first the governor and then the speed limiter.
WARNING! The airbag must be removed to remove or test the governor and speed limiter switches.
Check the cleanliness and condition of the steering wheel speed change switches and their connectors.
Check for ground on the steering wheel speed change switch connectors (see connector pin numbers on the appropriate wiring diagram)
Disconnect the battery.
Disconnect the computer from the on-board network. Check the cleanliness of the contacts and the condition of the connector.
Connect the universal contact board. Check for open and short circuits in the following circuits:
ECU, pin D2, connector A -► Steering wheel switch
ECU, track D3, connector A -► Steering wheel switch (see the pin numbers on the corresponding wiring diagram).
If the problem persists, handle other problems and then proceed to compliance.
DF109 Misfire at minimum fuel level
Misfire mixture at low fuel level.
Cause and effect: - Low fuel misfires leading to catalytic converter destruction.
If the following faults are present or stored, deal with them first:
– Fuel supply system: DF085, DF026, DF027, DF028 and DF029.
Requirements for diagnostics for a stored fault:
The fault is declared present after the engine is started.
Check if there is fuel in the tank.
Check fuel quality,
If a mixture misfire fault (DF059, 060, 061, 062, 065, 1.DEF or 2.DEF) is present or stored, it must be dealt with and fault DF109 can be ignored.
Requirements for diagnostics for a stored fault:
A fault is declared present under the following conditions:
- - Check for electrical problems.
- – Programming must be done
- - The engine must be warm (at least 75 °C)
- – With the engine idling, turn on all electrical consumers for 15 minutes.
If there are no misfire faults present or stored, low fuel was the cause of the misfire.
Remove fault DF109 from memory.
AFTER REPAIR
Make sure all problems are corrected.
Do not erase programming data.
To confirm repair results:
- - Troubleshoot electrical circuits.
- - Register programmable parameters.
- - Warm up the engine (at least 75 °C).
- – With the engine idling, turn on all electrical consumers for 15 minutes.
If the problem reappears, continue with the diagnosis.
DF110 catalytic converter
Reason: - HC emission threshold exceeded, allowed by the on-board diagnostic system
If other faults are present, deal with them first.
There should be no other faults present or stored in the fuel injection system.
After correcting the cause of the misfire, replace the catalytic converter.
AFTER REPAIR
Treat other possible problems. Clear fault information from memory.
DF125 torque meter programming
Reason: - programming failed
For your information: - The torque meter analyzes the crankshaft speed.
Requirements for diagnostics for a stored fault:
The fault is declared present after the starter has been operated for 10 seconds or the engine speed is greater than 600 rpm.
Reinitialize Programming:
Give command RZ008.
Torque meter programming:
Engage third gear and increase engine speed to 4000 rpm, then reduce engine speed until fuel is restored*.
Repeat the operation twice in a row.
In rare cases, a DF125 malfunction may occur. (This is the moment when, when the rpm is reduced with the accelerator pedal released, the crankshaft speed drops to idle and the engine starts to work again under load)
AFTER REPAIR
Follow "Diagnostic conditions for stored fault":
- – If the fault is present, continue handling the fault.
- - If the fault is stored, don't take it into account anymore.
Treat other possible problems. Clear fault information from memory.
DF126 interior heating element
Reason: - the information coming from the UCH does not correspond to the current value or is missing
Perform a multiplex network test.
If the problem persists, carry out a fault finding on the "Interior Central Electronic Switching Unit" system.
AFTER REPAIR
Treat other possible problems. Clear fault information from memory.
DF127 brake light switch
Reason: - malfunction of one of the two contacts of the brake light switch
Requirements for diagnostics for a stored fault:
The fault is declared present with the engine running, brake pedal depressed and cruise control switch in the "ON" position.
Check the condition of the pedal assembly.
Check the cleanliness and condition of the 2-pin brake light switch and its connector.
Disconnect the battery.
Disconnect the computer from the on-board network. Check the cleanliness of the contacts and the condition of the connector.
Connect the universal contact board instead of the ECU and check for open circuits and short circuits in the circuit:
ECU, channel E4, connector A -► Brake light switch (see pin numbers connector code on the corresponding wiring diagram).
If the problem persists, replace the switch.
AFTER REPAIR
Treat other possible problems. Clear fault information from memory.
DF128 brake light switch circuit 2
The cause is a malfunction of both contacts of the brake light switch
If fault DF127 is present, deal with it first.
Requirements for diagnostics for a stored fault:
The fault is declared present with the engine running, the brake pedal depressed, and the cruise control switch in the "ON" position at a given road speed.
Perform a multiplex network test.
If the problem persists, carry out a fault finding on the "Interior Central Electronic Switching Unit" system.
AFTER REPAIR
Treat other possible problems. Clear fault information from memory.
