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Self-diagnosis IV > < Self-diagnosis III

Octavia Mk1

Fault table of the fault code 16504 to 18262
   
Fault table of the fault code 16504 to 18262
Display -V.A.G 1552-Possible cause of faultPossible effectsRectifying fault
16504
Throttle valve potentiometer -G69-1)
Electrical fault in the circuit
t  Open circuit or short circuit to positive
t  Line has short-circuit to earth
t  -G69- defective
t  Acceleration jerks
t  Load alteration shock when releasing the accelerator
t  Idling control behaviour unstable
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
–  Check throttle valve potentiometer -G69- → Chapter
16505
Throttle valve potentiometer -G69-1)
implausible signal
t  Humidity and/or corrosion in the plug connection at the throttle valve potentiometer -G69-
t  -G69- defective
t  Acceleration jerks
t  Idling control behaviour unstable
t  Load alteration shock when releasing the accelerator
–  Check throttle valve potentiometer -G69- → Chapter
16506
Throttle valve potentiometer -G69-1)
t  Line interruption or short-circuit to earth in the signal line between -G69- and the engine control unit
t  Voltage supply for -G69- defective
t  -G69- defective
t  Acceleration jerks
t  Idling control behaviour unstable
t  Load alteration shock when releasing the accelerator
–  Check throttle valve potentiometer -G69- → Chapter
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
16507
Throttle valve potentiometer -G69-1)
Signal too high
t  Short circuit to positive in the signal line between - G69- and engine control unit
t  Earth distribution to -G69- defective
t  -G69- defective
t  Acceleration jerks
t  Load alteration shock when releasing the accelerator
–  Eliminate short-circuit to positive → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
–  Check throttle valve potentiometer -G69- → Chapter

1) Component part of the throttle valve control unit -J338-.
  Note
t  regarding fault code 16505:
t  The air flow rate (air mass) is compared with the throttle valve angle at the relevant speed.
t  re fault codes 16504 16505, 16506 and 16507:
t  As soon as one of the faults is detected, the control unit uses a learned replacement value from the speed.
t  If a fault occurs at the throttle valve potentiometer as well as at the air mass meter, no emergency operation function is possible. Consequence: the engine stalls.
   
Display -V.A.G 1552-Possible cause of faultPossible effectsRectifying fault
16514
Bank 1 - probe 1
electrical fault in the circuit
t  Corrosion due to humidity in the plug connection for lambda probe heater -Z19- or lambda probe -G39-
t  Lambda control goes into operation
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Short-circuit between lambda probe signal cable and lambda probe reference earth line
t  Poor idling
–  Test lambda control → Chapter
t  Amplitude of the signal line too small (lambda probe -G39- toxic or probe slots blocked or soiled)
t  Emission levels N.O.K.
t  Increased fuel consumption
–  Read measured value block, display group 007 → Chapter
–  Read measured value block, display group 021 → Chapter
16515
Bank 1 - Probe 1
Voltage too small
t  Short-circuit of the lambda probe signal line to earth or to shielding
t  Lambda control goes into operation
t  Poor idling
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Short-circuit of the lambda probe signal line to earth or to shielding
t  Emission levels N.O.K.
–  Function of the lambda control → Chapter
–  Read measured value block, display group 007 → Chapter
t  Lambda probe defective
t  Increased fuel consumption
–  Read measured value block, display group 021 → Chapter
16516
Bank 1 - Probe 1
Voltage too great
t  Short-ciruit of signal line to positive
t  Lambda control goes into operation
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
.
t  Lambda probe defective
t  Poor idling
–  Test lambda control → Chapter
16518
Bank 1 - probe 1
no activity
t  Lambda probe defective (dirty)
t  Increased fuel consumption
t  Emission levels N.O.K.
–  Read measured value block, display group 021 → Chapter
t  Line interruption between probe heater and engine control unit.
t  Sooting of spark plugs
 
t  Lambda probe heater does not operate
 
–  Check lambda probe heater → Chapter
16519
Bank 1 - probe 1
heating circuit electrical fault
t  Open circuit or short circuit to positive
t  Probe heating without function
–  Check lambda probe heater → Chapter
16705
Engine speed sender -G28-
implausible signal
t  Engine speed sender -G28- loose
t  Sensor rotor loose
t  Engine misfiring
–  Check engine speed sender -G28- → Chapter
16706
Engine speed sender -G28-
no signal
t  Signal line is interrupted or short-circuited to earth or pos.
t  Engine does not start
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Earth lead is interrupted or short-circuited to pos.
t  Engine stalls
 
t  -G28- loose and/or defective
 
–  -G28- test → Chapter
t  Line interruption to shielding of -G28-
  
t  Signal input in engine control unit defective (control unit defective)
 
–  Replacing engine control unit → Chapter
16710
Knock sensor 1 -G61-
implausible signal
t  -G61- loose and/or defective
t  reduced performance
–  Testing knock sensor → Chapter
t  Line interruption or short-circuit to earth and/or to screening in the signal line between the knock sensor and the engine control unit
t  Increased fuel consumption
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Signal input in engine control unit defective (control unit defective)
 
–  Replacing engine control unit → Chapter
16711
Knock sensor 1 -G61-
signal too low
t  -G61- loose and/or defective
t  Line short-circuit to earth
t  Increased fuel consumption
t  reduced performance
–  Testing knock sensor → Chapter
16712
Knock sensor 1 -G61-
signal too high
t  -G61- loose and/or defective
t  Line short-cicuit to pos.
t  Increased fuel consumption
t  reduced performance
–  Testing knock sensor → Chapter
16716
Knock sensor 2 -G66-
signal too low
t  -G66- loose and/or defective
t  Line short-circuit to earth
t  Increased fuel consumption
t  reduced performance
–  Testing knock sensor → Chapter
16717
Knock sensor 2 -G66-
signal too high
t  -G66- loose and/or defective
t  Line short-cicuit to pos.
t  Increased fuel consumption
t  reduced performance
–  Testing knock sensor → Chapter
16885
Vehicle speed signal
implausible signal
t  Vehicle speed sender defective
t  no AC compressor disconnection at full load
–  Check speed signal → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Line interruption or short-circuit between vehicle speed sender and speedometer sender
t  brief variation of idling speed from nominal speed
–  Read measured value block, display group 011, display field 3 → Chapter
t  Line interruption or short-circuit between dash panel insert and engine control unit
t  poor load alteration behaviour
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Speedometer defective
t  Malfunction on systems using the speed signal
–  Testing the speed signal → Chapter
16989
Control unit defective
t  Engine control unit defective
t  Engine does not start
–  Replacing engine control unit → Chapter
17733
Knock control cyl. 1
Regulating limit reached
t  Poor fuel quality (below 95 RON)
t  Increased fuel consumption
–  Fill with fuel of minimum 95 RON.
17734
Knock control cyl. 2
Regulating limit reached
t  abnormal engine running noises (loose ancillaries)
t  reduced performance
–  Eliminate cause of the abnormal engine running noises
–  Testing knock sensor → Chapter
17735
Knock control cyl. 3
Regulating limit reached
t  Line interruption of the screening of knock sensor 1 or 2
t  irregular engine running
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Loose contact of plug connections
t  Maximum speed is not reached
–  Read measured value block, display group 014 and 015 → Chapter
17736
Knock control cyl. 4
Regulating limit reached
t  Knock sensor with incorrectly tightened torque
 
–  Release knock sensor and tighten again to 20 Nm

   
Display -V.A.G 1552-Possible cause of faultPossible effectsRectifying fault
17913
Idling switch -F60-1)
does not close/interruption
t  Throttle valve jams
t  -F60- defective
t  Load alteration shock when releasing the accelerator
–  Check idling switch -F60- → Chapter
t  Throttle cable setting
t  Foot mat presses onto the accelerator pedal
t  Idling speed not within the specified value
–  Adjusting throttle control cable → Engine; Rep. Gr.20
t  Line interruption or short circuit to positive between idling switch -F60- and engine control unit
t  AC compressor is switched on only at higher engine speed
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Signal input in the engine control unit defective (engine control unit defective)
 
–  Replacing engine control unit → Chapter
17914
Idling switch -F60-1) does not open/short-circuit to earth
t  Humidity in the plug of the throttle valve control unit
t  -F60- defective
t  Idling control goes into operation
–  Check idling switch -F60- → Chapter
t  Short circuit to earth between idling switch -F60- and engine control unit
t  Idling speed not within the specified value
t  Load alteration shock when releasing the accelerator
t  AC compressor is switched on only at higher engine speed
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Signal input in the engine control unit defective (engine control unit defective)
 
–  Replacing engine control unit → Chapter

1) Component part of the throttle valve control unit -J338-.
   
Display -V.A.G 1552-Possible cause of faultPossible effectsRectifying fault
17915
Idling system learned value
bottom limit reached
t  Unmetered air in front of the throttle valve control unit
t  high idling
–  Eliminate unmetered air
17916
Idling system learned value
top limit reached
t  Intake system blocked (air filter or air intake channel)
t  no power output
–  Inspect intake system
for vehicles 08.97 ?
17920
Variable intake manifold changeover valve - N156-
Short circuit to positive
t  Short circuit to positive in wiring between variable intake manifold changeover -N156- and engine control unit
t  Acceleration deficit
–  -N156 - test → Chapter
t  -N156- defective
  
t  Signal input in the engine control unit defective (engine control unit defective)
 
–  Replacing engine control unit → Chapter
for vehicles 08.97 ?
17923
Variable intake manifold changeover valve - N156-
Short circuit to earth
t  Short circuit to earth in wiring between variable intake manifold changeover -N156- and engine control unit
t  Acceleration deficit
–  -N156 - test → Chapter
t  -N156- defective
  
t  Signal input in the engine control unit defective (engine control unit defective)
 
–  Replacing engine control unit → Chapter
for vehicles 08.97 ?
17924
Variable intake manifold changeover valve - N156-
Open circuit
t  Open circuit in wiring between variable intake manifold changeover valve -N156- and engine control unit
t  Acceleration deficit
–  -N156- test → Chapter
t  Voltage supply for -N156- defective
  
t  -N156- defective
  
t  Signal input in the engine control unit defective (engine control unit defective)
 
–  Replacing engine control unit → Chapter
17934
Bank 1, Camshaft adjustment - N205-
Short circuit to positive
t  Short-circuit to positive between solenoid valve 1 for camshaft adjustment -N205- and the engine control unit
 
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Check camshaft adjustment valve 1 -N205- faulty
t  Poor torque in lower speed range 1300 to 3600 rpm
–  Check camshaft adjustment valve 1 -N205- → Chapter
t  Fuse defective
 
–  Test fuse
t  Signal input in the engine control unit defective (engine control unit defective)
 
–  Replacing engine control unit → Chapter
17935
Bank 1, Camshaft adjustment - N205-
Short circuit to earth
t  Short-circuit to earth between solenoid valve 1 for camshaft adjustment -N205- and the engine control unit
 
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Check camshaft adjustment valve 1 -N205- faulty
t  Poor torque in lower speed range 1300 to 3600 rpm
–  Check camshaft adjustment valve 1 -N205- → Chapter
t  Fuse defective
 
–  Test fuse
17936
Bank 1, Camshaft adjustment -N205-
open circuit
t  Open circuit between camshaft adjustment valve 1 -N205- and engine control unit
t  Poor torque in lower speed range 1300 to 3600 rpm
–  Eliminate line interruption or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Fuse defective
 
–  Test fuse
17953
Throttle valve control
Malfunction
t  Voltage supply or earth distribution for throttle valve potentiometer -G69- and throttle valve positioner -G127- defective
t  increased idling speed
t  Load alteration shock when releasing the accelerator
–  Read measured value block, display group 023 → Chapter
t  Interruption in the signal line for -G69- and -G127-
 
–  Inspecting throttle valve control unit -J338- → Chapter
t  -G69- and -G127- defective
  
t  Throttle valve stiff or dirty
 
–  Clean throttle valve
17967
Throttle valve control unit -J338-
Fault in basic setting
t  Open idling switch
t  minimum stop not reached (jams)
t  Engine runs in emergency operation programme
–  Check idling switch → Chapter
–  Read measured value block, display field 4 → Chapter
17972
Throttle valve control unit -J338-
Voltage drop on basic setting
t  Voltage under 10 V during basic setting
 
–  Check voltage, read measured value block, display group 003, display field 2 → Chapter
17973
Throttle valve control unit
bottom limit not reached
t  Throttle valve jams
t  Throttle valve positioner jams/mechanically damaged.
t  Starting problems
t  poor throttle response
t  Starting problems
–  Check throttle valve for damage or dirt
–  Inspecting throttle valve control unit → Chapter
17978
Engine control unit inhibited
t  Start attempt with a non-authorised key
t  Manipulation attempt
t  Short-circuit in the communication cable
t  Engine starts and stops immediately
–  Adapt the 4AV control unit to the electronic immobiliser → Chapter
t  incorrect coding
t  fault in the immobilizer system
t  Immobilizer control unit defective/missing
 
–  Test immobiliser → Electrical System; Rep. Gr.96
t  Engine control system replaced and not adapted to immobilizer
  

  Note
t  regarding fault code 17978:
t  The immobilizer control electronics are located in the instrument cluster and can easily be replaced individually.
t  When attempting to start with a non-adapted key a static fault is stored in the memory. If a subsequent start attempt occurs with an adpated key the fault is changed to a sporadic fault.
   
Display -V.A.G 1552-Possible cause of faultPossible effectsRectifying fault
18010
Voltage supply tml. 30
Voltage too small
t  Battery was disconnected
t  permanent voltage supply at control unit was disconnected or line interruption
t  Initialisation values in the engine control unit is missing
–  Test voltage supply of engine control unit → Chapter
t  Fuse no. 10 or 29 defective
 
–  Test fuses
18020
Engine control unit incorrectly coded
t  Engine control unit incorrectly coded
t  Poor vehicle handling
t  Increase in pollution
t  different faults in the fault memory
–  Coding engine control unit → Chapter
for vehicles 08.97 ?
18034
databus drive
missing message from gearbox control unit
t  Faults in the databus lines to gearbox control unit
t  poor driveability (jerking when changing gears, load alteration shock)
–  Test databus cable to engine control unit pin 29+41 for open circuit or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Fault in the system of the automatic gearbox
 
–  Test automatic gearbox control unit → Automatic Gearbox; Rep. Gr.01
for vehicles 08.97 ?
18259
databus drive
missing message from ABS control unit
t  Databus lines to ABS control unit interrupted
t  no vehicle dynamic control
–  Test databus cable to engine control unit pin 29+41 for open circuit or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Fault in ABS system
 
–  Test ABS control unit → Running Gear; Rep. Gr.45
for vehicles 08.97 ?
18262
databus drive
Hardware defective
t  Faults in the databus lines to gearbox or ABS control unit
t  poor driveability (jerking when changing gears, load alteration shock)
t  no vehicle dynamic control
–  Test databus cable to engine control unit pin 29+41 for open circuit or short-circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations
t  Fault in the system of the automatic gearbox or ABS
 
–  Test ABS control unit → Running Gear; Rep. Gr.45
–  Test automatic gearbox control unit → Automatic Gearbox; Rep. Gr.01

   

Self-diagnosis IV > < Self-diagnosis III