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 -150
MR-413-X44-87B000$720.mif
V5
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Interpretation of parameters
UCH
Vdiag No.: 44
87B
PR076
BATTERY VOLTAGE AFTER REST
NOTESNo faults should be present or stored.
The battery voltage after rest represents the battery charge status.
9 V < PR076 < 14 V
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_PR076
87B -172
MR-413-X44-87B000$912.mif
V5
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Fault Finding Chart
UCH
Vdiag No.: 44
87B
ALP 29 Starter noisy
NOTESSpecial notes:
Check for faults using the diagnostic tool. Deal with the other faults first.
Use the W iring Diagrams Technical Note for New Twingo.
Check with LC023 Engine type that the engine type configured matches the vehicle. Otherwise perform CF028
Engine type to modify the configuration.
If the configuration is correct (see 16A Starting - Charging).
If the fault is still present, contact the Techline.
AFTER REPAIRCarry out a complete check using the diagnostic tool.
UCH_V44_ALP29
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
