
OBD and Air Supply
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Information on diagnostics
The diagnostic trouble codes P0097, P0102, P0400, P0172 and P0506 can be displayed on an on-board diagnostic system (OBD). They indicate a fault within the air supply system of the vehicle. You can find out the causes of these diagnostic trouble codes and what you can do to resolve the issue here.
PIERBURG PRODUCTS | ON-BOARD DIAGNOSTICS |
01 Activated carbon filter valve | 12 Engine control unit |
02 EGR valve | 13 Malfunction indicator lamp (MIL) |
03 Electric drive module | 14 Diagnostic plug |
04 Intake manifold/variable intake manifold | 15 OBD data scan tool |
05 Intake manifold pressure sensor | |
06 Throttle valve/regulating throttle | |
07 Air mass sensor (LMS) | |
08 Recirculating air valve | |
09 Pressure transducer (for actuating the VTG turbocharger) | |
10 Air filter (Kolbenschmidt) | |
11 Idle controller |
FROM PRACTICAL USE
FINDING AND REMEDYING FAULTS
DIAGNOSTIC TROUBLE CODE | P0097 | P0102, P0400 |
DISPLAYED FAULTS | Intake air temperature sensor – input signal too low • Plausibility check delivers incorrect reference values • Temperature sensor on air mass sensor is defective • Intake air temperature sensor faulty |
Mass air flow meter or air flow meter – input signal too low/exhaust gas recirculation – flow rate malfunction • Air mass sensor faulty • Stuck/carbonised EGR valve is always open • Basic setting of EGR valve not performed |
NEXT STEPS/ POSSIBLE REMEDIES | • Check air mass sensor, replace if defective • Check intake air temperature sensor, replace if necessary |
• Check power supply to mass air flow meter and EGR valve • Check mass air flow meter, replace if defective • Check EGR valve: - If the EGR valve is always open, exhaust gas is recirculated permanently - If the EGR valve is stuck, replace and find out the causes of the sticking • Once a new EGR valve has been installed: perform basic setting (engine tester) |
DIAGNOSTIC TROUBLE CODE | P0172 | P0506 |
DISPLAYED FAULTS | Mixture too rich • Activated carbon filter solenoid valve stuck (permanently open): Fuel-enriched air from the activated carbon filter is drawn into the intake air system • Diaphragm of the pneumatic fuel pressure regulator leaking: Fuel is drawn into the intake air system through the vacuum line • Stuck/carbonised EGR valve is always open |
Idle control – engine speed below set-point value • Idle controller soiled/stuck • Incorrect input signals arriving from the engine control unit • Throttle valve stiff/stuck |
NEXT STEPS/ POSSIBLE REMEDIES | • Activated carbon filter solenoid valve, replace if necessary • Check fuel pressure regulator, replace if necessary • Check EGR valve: - If the EGR valve is always open, exhaust gas is recirculated permanently - If the EGR valve is stuck, replace and find out the causes of the sticking |
• Check idle controller using an oscilloscope • Replace stuck/carbonised idle controller • Read out input signals of the idle controller using the diagnostic tester • Replace stuck/carbonised throttle valve and find out the causes of the sticking |