PETROL INJECTION
Fault finding – Introduction17B
17B-3V12 MR-372-J84-17B000$045.mif
SAGEM 3000
Program No.: A7
Vdiag No.: 44, 48
Faults
Faults are declared present or stored (depending on whether they appeared in a certain context and have
disappeared since, or whether they remain present but are not diagnosed within the current context).
The present or stored status of faults should be taken into consideration when the diagnostic tool is switched on
following + after ignition feed being activated (without any system components being active).
For a present fault, apply the procedure described in the Interpretation of faults section.
For a stored fault, note the faults displayed and apply the Notes section.
If the fault is confirmed when the instructions in the Notes section are applied, the fault is present. Deal with the
fault.
If the fault is not confirmed, check:
– the electrical lines which correspond to the fault,
– the connectors for these lines (for oxidation, bent pins, etc.),
– the resistance of the component detected as faulty,
– the condition of the wires (melted or split insulation, wear).
Conformity check
The aim of the conformity check is to check the statuses and parameters that do not produce a fault display on the
diagnostic tool when they are inconsistent. Therefore, this stage is used to:
– carry out fault finding on faults that do not have a fault display, and which may correspond to a customer complaint.
– check that the system is operating correctly and that there is no risk of a fault recurring after repairs.
This section gives the fault finding procedures for statuses and parameters and the conditions for checking them.
If a status is not behaving normally or a parameter is outside the permitted tolerance values, consult the
corresponding fault finding page.
Customer complaints - Fault finding chart
If the test with the diagnostic tool is OK but the customer complaint is still present, the fault should be treated by
customer complaints.
A summary of the overall procedure to follow is provided on the following
page in the form of a flow chart.
JSAA741.0
PETROL INJECTION
Fault finding – Introduction17B
17B-6V12 MR-372-J84-17B000$045.mif
SAGEM 3000
Program No.: A7
Vdiag No.: 44, 48
5. FAULT FINDING LOG
You will always be asked for this log:
– when requesting technical assistance from Techline,
– for approval requests when replacing parts for which approval is mandatory,
– to be attached to monitored parts for which reimbursement is requested. The log is needed for warranty
reimbursement, and enables better analysis of the parts removed.
6. SAFETY INSTRUCTIONS
Safety rules must be observed during any work on a component to prevent any damage or injury:
– check the battery voltage to avoid incorrect operation of computer functions,
– use the proper tools.
7. FAULT FINDING
Stored faults are managed the same way for all sensors and actuators.
A stored fault is cleared after 128 recurrence-free starts.IMPORTANT!IMPORTANT
Any fault on a complex system requires thorough fault finding with the appropriate tools. The
FAULT FINDING LOG, which should be completed during the fault finding procedure, ensures a
record is kept of the procedure carried out. It is an essential document when consulting the
manufacturer.
IT IS THEREFORE MANDATORY TO FILL OUT A FAULT FINDING LOG EACH TIME FAULT FINDING IS
CARRIED OUT.
JSAA741.0
PETROL INJECTION
Fault finding – System operation17B
17B - 7V12 MR-372-J84-17B000$090.mif
SAGEM 3000
Program No.: A7
Vdiag No.: 44, 48PETROL INJECTION
Fault finding – System operation
1. SYSTEM OPERATION
Composition
The injection system consists of the:
– accelerator potentiometer,
– accelerator pedal switch,
– TDC sensor,
– atmospheric pressure sensor,
– air temperature sensor,
– coolant temperature sensor,
– freon pressure sensor,
– upstream oxygen sensor,
– downstream oxygen sensor,
– cruise control switch,
– steering column switch,
– cruise control on/off switch,
– brake lights switch,
– fuel vapour absorber,
– injection computer,
– motorised throttle valve,
– four injectors,
– four pencil coils,
– + turbocharging pressure sensor,
– coolant pump
– turbocharging solenoid valve.
Computer
SAGEM S3000 flash EEPROM 128-track computer controlling the injection and the ignition.
Multipoint injection in sequential mode.
Connections to the other computers:
– Protection and Switching Unit (UPC)
– Passenger Compartment Control Unit (UCH),
– Automatic Transmission Electronic Control Unit (AUTO ECU).
JSAA741.0
MR-372-J84-17B000$090.mif
PETROL INJECTION
Fault finding – System operation17B
17B - 8V12 MR-372-J84-17B000$090.mif
SAGEM 3000
Program No.: A7
Vdiag No.: 44, 48
Engine immobiliser
The immobiliser function is managed by the UCH and engine management computers.
Before any driver request (card + button press), the engine management and UCH computers exchange
authentication CAN frames to determine whether or not to start the engine.
After more than five consecutive failed authentication attempts, the engine management computer goes into
protection (anti-scanning) mode and no longer tries to authenticate the UCH computer. It only leaves this mode when
the following sequence of operations is carried out:
– the ignition is left on for at least 60 seconds,
– ignition is switched off,
– the injection computer self-supply cuts out when it should (the time varies according to engine temperature).
After this, only one authentication attempt is allowed. If it too fails, the sequence of operations described above must
be repeated.
If the engine management computer still fails to unlock, contact the Techline.
Impact detected
If an impact has been registered by the injection computer (Impact detected), switch off the ignition for 10 seconds
then switch it back on to start the engine. Then clear any faults.
WARNING
Disconnect the injection computer when carrying out any welding work on the vehicle.
JSAA741.0
PETROL INJECTION
Fault finding – Interpretation of statuses17B
17B - 142V12 MR-372-J84-17B000$540.mif
SAGEM 3000
Program No.: A7
Vdiag No.: 44, 48
ET055
UPSTREAM SENSOR RICHNESS LOOP
NOTESThere must be no present or stored faults.
Check the cleanliness and condition of the upstream oxygen sensor connections.
Repair if necessary.
With the ignition on, check for + 12 V on track A of the upstream oxygen sensor connector.
If +12V is not present:
– disconnect the battery,
– disconnect the connector marked PPM1 in the Protection and Switching Unit,
– check the cleanliness and condition of the connections,
– using the Universal bornier, check for continuity on the following connection:
Protection and Switching Unit track 2 connector PPM1 track A of the upstream oxygen sensor
Reconnect the Protection and Switching Unit connector and reconnect the battery.
With the ignition on, if there is still no +12V at the upstream oxygen sensor connector, there is a fault in the
Protection and Switching Unit.
Contact the Techline.
Disconnect the battery and the injection computer.
Check the cleanliness and condition of the connections.
Using the universal bornier, check the insulation and continuity on the following connections:
Injection computer connectorC, track C1 track D of the upstream oxygen sensor
Injection computer, connectorC, track B1 track C of the upstream oxygen sensor
Injection computer, connectorC, track L2 track B of the upstream oxygen sensor
Repair if necessary.
Measure the heating resistance between tracks A and B of the upstream oxygen sensor.
Replace the upstream oxygen sensor if the resistance is not approximately 9 at 20 °C.
Check the condition and secure fitting of the upstream oxygen sensor.
If the vehicle is driven frequently in town, carry out a decoking procedure.
JSAA741.0
PETROL INJECTION
Fault finding – Interpretation of parameters17B
17B - 163V12 MR-372-J84-17B000$675.mif
SAGEM 3000
Program No.: A7
Vdiag No.: 44, 48
PR098
UPSTREAM OXYGEN SENSOR VOLTAGE
NOTESThere must be no present or stored faults.
Check the cleanliness and condition of the upstream oxygen sensor connections.
Repair if necessary.
Disconnect the battery and the injection computer.
Check the cleanliness and condition of the connections.
Using the universal bornier, check the insulation and continuity on the following connections:
Injection computer connectorC, track C1 track D of the upstream oxygen sensor
Injection computer, connectorC, track B1 track C of the upstream oxygen sensor
Repair if necessary.
Check that the upstream oxygen sensor is secure.
Repair if necessary.
If the vehicle is driven frequently in town, carry out a decoking procedure.
Check that there are no leaks in the exhaust system, from the manifold to the catalytic converter.
Repair if necessary.
If the fault is still present, replace the upstream oxygen sensor.
If the fault has still not been cured, continue with the checks.
Check:
– the condition of the air filter,
– that the air inlet circuit is not blocked,
– the condition and conformity of the spark plugs,
– that the catalytic converter is not clogged,
– the sealing between the throttle valve and inlet manifold,
– the manifold pressure sensor sealing,
– the fuel vapour absorber bleed, which must not be jammed open,
– the fuel vapour absorber bleed system sealing,
– the brake servo system sealing,
– the cylinder head oil vapour recovery system sealing,
– the sealing between the inlet manifold and cylinder head,
– the exhaust pipe sealing between the cylinder head and catalytic converter.
– the fuel flow rate and pressure.
JSAA741.0
PETROL INJECTION
Fault finding – Interpretation of parameters17B
17B - 165V12 MR-372-J84-17B000$675.mif
SAGEM 3000
Program No.: A7
Vdiag No.: 44, 48
PR099
DOWNSTREAM OXYGEN SENSOR VOLTAGE
NOTESThere must be no present or stored faults.
Check the cleanliness and condition of the downstream oxygen sensor connections.
Repair if necessary.
Disconnect the battery and the injection computer.
Using the universal bornier, check the insulation and continuity on the following connections:
Injection computer, connectorC, track A2 track D of the downstream oxygen sensor
Injection computer, connectorC, track B2 track C of the downstream oxygen sensor
Repair if necessary.
Check that the downstream oxygen sensor is secure.
Repair if necessary.
If the vehicle is driven frequently in town, carry out the unclogging procedure (oxygen sensors and catalytic
converter clogging).
Check that the exhaust pipe is completely leak free.
Repair if necessary.
Replace the downstream oxygen sensor.
If the fault is still present, the catalytic converter is certainly damaged.
If the catalytic converter is defective, determine the cause of the destruction, otherwise the new catalytic
converter may be damaged in turn.
Remove the catalytic converter.
Possible reasons for the destruction of a catalytic converter:
–deformation (impact),
–thermal shock (cold water splashed onto a hot catalytic converter can damage it),
–defective injector or ignition: the catalytic converter is damaged by contact with fuel (coil fault, coil control fault,
injector jammed open),
–injector leak,
–abnormal oil or coolant consumption (defective cylinder head gasket),
–use of a fuel additive or other equivalent product (obtain information from the customer because this type of
product can contaminate the catalytic converter and render it useless sooner or later).
Look up the service history of the vehicle or, if this is not possible, ask the customer if the vehicle has had injection
or ignition faults.
If the cause of the catalytic converter damage has been found and the fault has disappeared, replace the
catalytic converter.
AFTER REPAIRRepeat the conformity check from the start.
JSAA741.0