engine AUDI A4 1998 B5 / 1.G APB Engine Motronic Syst
Page 29 of 166
01-25
 
DTC  
Description of 
malfunction  
Corrective action  
SAE  
VAG  
  
  
P0156   16540   02 Sensor Circ., Bank2-
Sensor2  
Malfunction 
2)  - Check oxygen sensor heater   Page 24
-114
P0157   16541   02 Sensor Circ., Bank2-
Sensor2  
Low Voltage 
2)  - Check oxygen sensor signal wire and activation   Page 24
-122
P0158   16542   02 Sensor Circ., Bank2-
Sensor2  
High Voltage 
2)    
P0159   16543   02 Sensor Circ., Bank2-
Sensor2  
Slow Response 2)  - Check oxygen sensor and oxygen sensor control behind catalytic 
converter  Page 24
-100
 
P0160   16544   02 Sensor Circ., Bank2-
Sensor2  
No Activity Detected 
2)  - Check oxygen sensor heater   Page 24
-114
2) With this malfunction the exhaust Malfunction Indicator Light (MIL) is only switched on by the ECM, if the malfunction is 
recognized after the engine has been restarted. Significance of MIL   Page 01
-3 .  
Pa
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Page 30 of 166
01-26
 
DTC  
Description of 
malfunction  
Corrective action  
SAE  
VAG  
  
  
P0236   16620   Charge air pressure 
sensor -G31-  
Implausible signal   Repair Manual, 2.7 Liter V6 5V BiTurbo Engine Mechanical, Engine Code(s): 
APB, Repair Group 21; Boost pressure system with turbocharger; charge air pressure sensor 
-G31
-, checking
   
P0237   16621   Turbocharger Boost 
Sensor (A) Circ  
Low Input 
2)   Repair Manual, 2.7 Liter V6 5V BiTurbo Engine Mechanical, Repair Group 21; 
Turbocharger; Checking Charge Air Pressure Sensor -G31   
P0238   16622   Turbocharger Boost 
Sensor (A) Circ  
High Input 
2)    
2) With this malfunction the exhaust Malfunction Indicator Light (MIL) is only switched on by the ECM, if the malfunction is 
recognized after the engine has been restarted. Significance of MIL   Page 01
-3 .  
Pa
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ystem, On Board Dia
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Page 31 of 166
01-27
 
DTC  
Description of malfunction  
Corrective action  
SAE  
VAG  
  
  
P0300   16684   Random/Multiple Cylinder  
Misfire Detected
2)  - Check cause for misfire   Page 28
-52
P0301   16685  
Cyl.1 Misfire Detected 
2)  
- Check fuel tank level
P0302   16686  
Cyl.2 Misfire Detected 2)  
  
P0303   16687  
Cyl.3 Misfire Detected 2)  
  
P0304   16688  
Cyl.4 Misfire Detected 2)  
  
P0305   16689  
Cyl.5 Misfire Detected 2)  
  
P0306   16690  
Cyl.6 Misfire Detected 2)  
  
2) With this malfunction the exhaust Malfunction Indicator Light (MIL) is only switched on by the ECM, if the malfunction is 
recognized after the engine has been restarted. Significance of MIL   Page 01
-3 .  
The Malfunction Indicator Light (MIL) will blink if the Engine Control Module (ECM) recognizes misfire that could damage the 
catalytic converters. 
Notes:  
 
On malfunction which could be caused by lack of fuel (e.g.: misfire) the malfunction P1250 "Fuel level too low" will be 
displayed in addition. That means, the misfiring was detected due to lack of fuel in the tank and not due to a technical 
malfunction. 
Pa
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Page 33 of 166
01-28
 
DTC  
Description of malfunction  
Corrective action  
SAE  
VAG  
  
  
P0321   16705   Ign./Distributor Eng. Speed Inp. Circ.  
Range/Performance
2)  - Check Engine Speed Sensor   Page 28
-21
P0322   16706   Ign./Distributor Eng. Speed Inp. Circ.  
No Signal 
2)    
P0327   16711   Knock Sensor 1 Circ.  
Low Input  - Check Knock Sensor   Page 28
-41
P0328   16712   Knock Sensor 1 Circ.  
High Input    
P0332   16716   Knock Sensor 2 Circ.  
Low Input    
P0333   16717   Knock Sensor 2 Circ.  
High Input    
P0341   16725   Camshaft Pos. Sensor Circ.  
Range/Performance 
2)  - Check Camshaft Position Sensor   Page 28
-45
P0346   16730   Camshaft Pos. Sensor Circ. 2  
Range/Performance 
2)    
Pa
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Page 34 of 166
2) With this malfunction the exhaust Malfunction Indicator Light (MIL) is only switched on by the ECM, if the malfunction is 
recognized after the engine has been restarted. Significance of MIL   Page 01
-3 .  
Pa
ge 34 of 166 Motronic s
ystem, On Board Dia
gnostic 
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)
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pair&id=AUDI.B5.FU04.01.1 
Page 35 of 166
01-29
 
DTC  
Description of 
malfunction  
Corrective action  
SAE  
VAG  
  
  
P0421   16805   Warm Up Catalyst, 
Bank 1  
Efficiency Below 
Threshold 
2)   Repair Manual, 2.7 Liter V6 5V BiTurbo Engine Mechanical, Repair Group 26; 
Components of Exhaust system removing and installing, Catalytic converter 
removing and installing    - Generate readiness code   Page 01
-99
 , if same DTC is displayed again, replace 
warm up catalytic converter bank 1 
P0431   16815   Warm Up Catalyst, 
Bank 2  
Efficiency Below 
Threshold 
2)   Repair Manual, 2.7 Liter V6 5V BiTurbo Engine Mechanical, Repair Group 26; 
Components of Exhaust system removing and installing, Catalytic converter 
removing and installing    - Generate readiness code   Page 01
-99
 , if same DTC is displayed again, replace 
warm up catalytic converter bank 1 
2) With this malfunction the exhaust Malfunction Indicator Light (MIL) is only switched on by the ECM, if the malfunction is 
recognized after the engine has been restarted. Significance of MIL   Page 01
-3 .  
Important note:  
The warm up catalytic converters are located between the two oxygen sensors of the relevant cylinder bank. The warm up 
catalytic converters (little smaller than main catalytic converter) are located closer to the engine, not to be misunderstood with 
the main catalysts you see immediately once the vehicle is lifted. 
Pa
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Page 36 of 166
01-30
 
DTC  
Description of 
malfunction  
Corrective action  
P0441   16825   EVAP Emission Contr. 
Sys. Incorrect  
Purge Flow 
2)  - Check EVAP canister purge regulator valve, perform output Diagnostic Test 
Mode (DTM)   Page 01
-75
 
P0442   16826   EVAP Emission Contr. 
Sys. (Small Leak)  
Leak Detected 
2)  - Check EVAP system and tank system for leaks
P0455   16839   EVAP Emission Contr. 
Sys. (Gross Leak)  
Leak Detected   Repair Manual, Fuel Supply System, Repair Group 20, Components of EVAP 
system servicing, carry out tank leak test
   
P0456   16840   Tank ventilation system  
Pin-hole leak detected  
 Repair Manual, 2.7 Liter V6 5V BiTurbo Engine Mechanical, Repair Group 20; 
Fuel supply, gas engine; EVAP canister system components, servicing; tank leak diagnostic, performing.
    - Checking fuel supply and ventilation systems for leaks
2) With this malfunction the exhaust Malfunction Indicator Light (MIL) is only switched on by the ECM, if the malfunction is 
recognized after the engine has been restarted. Significance of MIL   Page 01
-3 .  
Pa
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Page 38 of 166
Diagnostic for Cruise Control System
   
2) With this malfunction the exhaust Malfunction Indicator Light (MIL) is only switched on by the ECM, if the malfunction is 
recognized after the engine has been restarted. Significance of MIL   Page 01
-3 .  
Pa
ge 38 of 166 Motronic s
ystem, On Board Dia
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Page 39 of 166
01-32
 
DTC  
Description of malfunction  
Corrective action  
SAE  
VAG  
  
  
P0601   16985   Internal Contr. Module Memory  
Check Sum Error
2)  - Replace Engine Control  
Module (ECM)   Page 24
-24
P0604   16988   Internal Contr. Module Random Access  
Memory (RAM) Error 
2)    
P0605   16989  
Internal Contr. Module ROM Test Error 
2)  
  
P0606   16990   Control module faulty  
- Replace Engine Control Module (ECM)   Page 24
-24
2) With this malfunction the exhaust Malfunction Indicator Light (MIL) is only switched on by the ECM, if the malfunction is 
recognized after the engine has been restarted. Significance of MIL   Page 01
-3 .  
Pa
ge 39 of 166 Motronic s
ystem, On Board Dia
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)
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yp
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pair&id=AUDI.B5.FU04.01.1 
Page 40 of 166
01-33
 
DTC  
Description of malfunction  
Corrective action  
SAE  
VAG  
  
  
P1102   17510   O2 Sensor Heating Circ., Bank1-
Sensor1  
Short to B+ 
2)  - Check oxygen sensor heater   Page 24
-114
P1105   17513   O2 Sensor Heating Circ., Bank1-
Sensor2  
Short to B+ 
2)    
P1107   17515   O2 Sensor Heating Circ., Bank2-
Sensor1  
Short to B+ 2)    
P1110   17518   O2 Sensor Heating Circ., Bank2-
Sensor2  
Short to B+ 2)    
P1111   17519   O2 Control (Bank 1)  
System too lean  - Check oxygen sensor adaptation values and oxygen sensor control 
 Page 24
-86
 
P1112   17520   O2 Bank 1  
System too rich    
  2) With this malfunction the exhaust Malfunction Indicator Light (MIL) is only switched on by the ECM, if the malfunction is 
recognized after the engine has been restarted. Significance of MIL   Page 01
-3 .  
Pa
ge 40 of 166 Motronic s
ystem, On Board Dia
gnostic 
(OBD
)
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yp
e=re
pair&id=AUDI.B5.FU04.01.1