87B-66
MR-413-X44-87B000$432.mif
V5
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Interpretation of faults
UCH
Vdiag No.: 44
87B
DF140
PRESENT
OR
STOREDVOLTAGE REGULATION
1.DEF: Voltage too low
2.DEF: Voltage too high
NOTESThe fault is declared present after:
switching on the ignition and waiting 1 minute.
Note:
The on-board network voltage is less than 0.89 times the battery voltage setpoint.
The battery may be used to supply all of the energy. The alternator voltage setpoint is
fixed as soon as the fault appears. Once the fault has been confirmed, the alternator
voltage setpoint is 14.3 V. Regulation resumes as soon as the fault disappears.
Effect on system:
The battery warning light comes on when the fault appears and goes out as soon as
the fault disappears.
Run command AC130 Alternator regulation without any electrical consumers:
–Wait 20 seconds.
–For 10 seconds, the voltage of the alternator (component code 103) should be equal to 15 V +/- 0.2 V at the
battery terminals.
–Wait 20 seconds.
–For 10 seconds, the voltage of the alternator (component code 103) should be equal to 13 V +/- 0.2 V at the
battery terminals.
If the voltages are not correct (see 80A, Battery, and see 16A, Starting charging).
Run command AC130 Alternator regulation without any electrical consumers:
–Wait 20 seconds.
–For 10 seconds the voltage of the alternator (component code 103) should be equal to 15 V + /- 0.2 V at the
terminals of the alternator (between the + terminal of the alternator (component code 103) and the engine
earth).
–Wait 20 seconds.
– For 10 seconds the voltage of the alternator should be equal to 13 V + /- 0.2 V at the terminals of the
alternator (component code 103) (between the + terminal of the alternator (component code 103) and the
engine earth).
If the voltages are not correct, check the conformity of the engine earth.
Check the condition and connection of the 1-track connector of component 103 (tabs bent, oxidised, broken).
Check for + 12 V on connection BPDA of component 103.
Check the continuity and insulation of the following connections:
●Connection code BPDA between components 103 and 163.
●Connection code 2N between components 103 and 645.
If the connection or connections are faulty and there is a repair procedure (see Technical Note 6015A, Electrical
wiring repair, Wiring: Precautions for repair), repair the wiring, otherwise replace it.
If the problem is still present, contact the Techline.
AFTER REPAIRCarry out another fault finding check on the system.
Clear the stored faults.
Deal with any other faults.
UCH_V44_DF140
87B-82
MR-413-X44-87B000$480.mif
V5
UCH
Vdiag No.: 44PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Conformity check87B
SUB-FUNCTION: BATTERY
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool
(fault reading and configuration checks).
Application condition: engine stopped, + after ignition feed present.
FunctionParameter or Status
Checked or ActionDisplay and notes Fault finding
Battery voltagePR001:Battery voltage9 V < X < 16 VIn the event of a fault, run fault
finding on the charging circuit
(see 80A, Battery).
PR074:Battery setpoint
voltageIndicates the battery
setpoint in V.In the event of a fault, apply the
interpretation of parameter
PR074.
PR076:Battery voltage after
restIndicates the battery
voltage after rest in V.In the event of a fault, apply the
interpretation of parameter
PR076.
Alternator
operationET142:Engine operating
phaseSTOPPED
STARTING
RUNNING
STALLEDIn the event of a fault, apply the
interpretation of status ET142.
87B-83
MR-413-X44-87B000$480.mif
V5
UCH
Vdiag No.: 44PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Conformity check87B
SUB-FUNCTION: ALTERNATOR
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool
(fault reading and configuration checks).
Application condition: engine stopped, + after ignition feed present.
FunctionParameter or Status
Checked or ActionDisplay and notes Fault finding
Battery voltagePR073:Alternator charge
signalIndicates the
alternator charge in V.In the event of a fault, apply the
interpretation of parameter PR073.
Alternator
setpointPR075:Alternator setpoint
voltage
Indicates the alternator
setpoint in V.In the event of a fault, apply the
interpretation of parameter PR075.
Battery voltagePR001:Battery voltage9 V < X < 16 VIn the event of a fault, run fault finding
on the charging circuit (see, 80A
Battery), run fault finding on the
multiplex network (see 88B,
Multiplex) and run fault finding on the
injection (see 13B, Diesel injection
or 17B, Petrol injection).
EnginePR024:Engine coolant
temperature˚C
PR025:Engine speedrpmIn the event of a fault, run fault finding
on the multiplex network (see 88B,
Multiplex) and run fault finding on the
injection (see 13B, Diesel injection
or 17B, Petrol injection).
ET142:Engine operating
phaseSTOPPED
STARTING
RUNNING
STALLEDIn the event of a fault, apply the
interpretation of status ET142.
AlternatorAC130:Alternator regulationIndicates the
regulation of the
alternator in volts.In the event of a fault, run fault finding
on the charging circuit (see 80A,
Battery).
87B -144
MR-413-X44-87B000$672.mif
V5
87B
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Parameter summary table
Tool parameter Diagnostic tool title
PR002External temperature
PR056Number of keys allocated
PR073Alternator charge signal
PR074Battery setpoint voltage
PR075Alternator setpoint voltage
PR076Battery voltage after rest
MR-413-X44-87B000$672.mif
UCH
Vdiag No.: 44
87B -147
MR-413-X44-87B000$720.mif
V5
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Interpretation of parameters
UCH
Vdiag No.: 44
87B
PR073
ALTERNATOR CHARGE SIGNAL
NOTESNo faults should be present or stored.
Note:
In the event of a malfunction, the value will by 99.6% (engine running).
Depending on the battery charge status, the operating phase and the battery temperature, the UCH determines
what the voltage across the battery terminals should be.
When the battery charge drops, and PR076 Battery voltage after rest decreases, the UCH can temporarily
increase the PR075 Alternator setpoint voltage by 1 V and for a period of 15 minutes after switching on + after
ignition feed.
Before and during starting, PR075 Alternator setpoint voltage is fixed at 10.7 V.
A maximum of 30 seconds after the engine has started, the UCH sets PR075 Alternator setpoint voltage to the
optimum value calculated.
The injection computer can also control the alternator (component code 103) regulation voltage.
The injection computer sends the maximum authorised power delivered by the engine, to the UCH via the
multiplex network.
If the power available by the engine is less than the power consumed by the alternator (component code 103),
the UCH reduces PR075 Alternator setpoint voltage.
0 % < PR073 < 100 %
In the event of a fault, carry out a complete check on the battery and the charging circuit (see Technical Note
16A, Starting-Charging).
If the fault is still present, contact Techline.
AFTER REPAIRRepeat the conformity check from the start.
UCH_V44_PR073
87B -148
MR-413-X44-87B000$720.mif
V5
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Interpretation of parameters
UCH
Vdiag No.: 44
87B
PR074
BATTERY SETPOINT VOLTAGE
NOTESNo faults should be present or stored.
Depending on the battery charge status, the operating phase and the battery temperature, the UCH determines
what the voltage across the battery terminals should be.
When the battery charge drops, and PR076 Battery voltage after rest decreases, the UCH can temporarily
increase the PR075 Alternator setpoint voltage by 1 V and for a period of 15 minutes after switching on + after
ignition feed.
Before and during starting, PR075 Alternator setpoint voltage is fixed at 10.7 V.
A maximum of 30 seconds after the engine has started, the UCH sets PR075 Alternator setpoint voltage to the
optimum value calculated.
The injection computer can also control the alternator (component code 103) regulation voltage.
The injection computer sends the maximum authorised power delivered by the engine, to the UCH via the
multiplex network.
If the power available by the engine is less than the power consumed by the alternator (component code 103),
the UCH reduces PR075 Alternator setpoint voltage.
In the event of a fault, perform a complete check on the battery and charging circuit (see 80A, Battery).
If the fault is still present, contact Techline.
AFTER REPAIRRepeat the conformity check from the start.
UCH_V44_PR074
87B -149
MR-413-X44-87B000$720.mif
V5
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Interpretation of parameters
UCH
Vdiag No.: 44
87B
PR075
ALTERNATOR SETPOINT VOLTAGE
NOTESNo faults should be present or stored.
Depending on the battery charge status, the operating phase and the battery temperature, the UCH determines
what the voltage across the battery terminals should be.
When the battery charge drops, and PR076 Battery voltage after rest decreases, the UCH can temporarily
increase the PR075 Alternator setpoint voltage by 1 V and for a period of 15 minutes after switching on + after
ignition feed.
Before and during starting, PR075 Alternator setpoint voltage is fixed at 10.7 V.
A maximum of 30 seconds after the engine has started, the UCH sets PR075 Alternator setpoint voltage to the
optimum value calculated.
The injection computer can also control the alternator (component code 103) regulation voltage.
The injection computer sends the maximum authorised power delivered by the engine, to the UCH via the
multiplex network.
If the power available by the engine is less than the power consumed by the alternator, the UCH reduces PR075
Alternator setpoint voltage.
In the event of a fault, perform a complete check on the battery and charging circuit (see 80A, Battery).
If the fault is still present, contact Techline.
AFTER REPAIRRepeat the conformity check from the start.
UCH_V44_PR075
87B -173
MR-413-X44-87B000$912.mif
V5
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Fault Finding Chart
UCH
Vdiag No.: 44
87B
ALP 30 Low light intensity
NOTESCheck the battery voltage (see 80A Battery).
Check for faults using the diagnostic tool. Deal with the other faults first.
With the engine running at idle speed, run command AC130 Alternator regulation.
–Wait 20 seconds.
–For 10 seconds the voltage of the alternator (component code 103) should be equal to 15 V ± 0.2 V, when
using a multimeter to measure on connection BPDA between components 103 and 645.
–Wait 20 seconds.
–For 10 seconds the voltage of the alternator (component code 103) must be equal to 13 V ± 0.2 V when
measuring between the alternator terminal (component code103) and the earth on connection 2N using a
multimeter.
If the values measured are not correct, check the starting - charging circuit (see 16A Starting - Charging) and
check the battery (see 80A, Battery).
If the fault is still present, contact the Techline.
AFTER REPAIRCarry out a complete check using the diagnostic tool.
UCH_V44_ALP30