2001 Eurovan - Diagnostics Help for a P0172 DTC

Thread Tools
 
Search this Thread
 
  #1  
Old 04-26-2016, 04:41 PM
hillhuggr's Avatar
Junior Member
Thread Starter
Join Date: Apr 2016
Posts: 2
Default 2001 Eurovan - Diagnostics Help for a P0172 DTC

Have a P0172 DTC stored (Rich fuel mix condition indicated) in the ECU (2.8L VR6 engine). Eurovan runs good but won't pass emissions test until all DTCs are cleared.

This indicates to me a probable faulty O2 Sensor. How do I determine that as a fact? Is there a way to measure the O2 sensor performance or at least identify which of the 2 sensors is bad?

Thanks for the help!

Tom
 
  #2  
Old 04-27-2016, 05:52 AM
Keithuk's Avatar
Super Moderator
Join Date: Sep 2009
Location: Stoke on Trent, England
Posts: 2,648
Default

Welcome to the forum Tom.


VAG Error Code: 16556/000370
EOBD II Error Code: P0172

Fault Location:
Fuel Trim, Bank 1 - System too Rich

Possible Cause:
Malfunction Indicator Lamp (MIL)(K83) active.
Excessive Fuel Consumption.
Irregular behaviour

Fuel system.
Excessive fuel pressure.
Leaking or contaminated fuel injectors.
Leaking fuel pressure regulator.
Low fuel pressure or running out of fuel.
Vapour recovery system.
Air leaks after the Mass air flow (MAF) sensor.
Faulty Mass Air Flow (MAF) Sensor (G70).
Engine Coolant Temperature Sensor (G62).
Vacuum leaks.
Improper seated engine oil dipstick.
Stuck Exhaust Gas Recirculation (EGR) valve.
Oil overfill.
Cam timing.
Cylinder compression.
Activated Charcoal Filter Solenoid Valve 1 (N80).
Fuel pressure.
Injector(s).
Exhaust leaks before or near Heated Oxygen Sensors (G39).
Read Measuring Value Blocks (MVB).
At idle Adaptive value < -5.02%.
At part load Adaptive value < -21%.

Special Notes:
Fuel Trim Information.

When is the code detected?:
Fuel injection system does not operate properly.
The amount of mixture ratio compensation is too large. (The mixture ratio is too rich.)

Description:
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.

In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the Engine Control Module (ECM) judges the condition as the fuel injection system malfunction and light up the Malfunction Indicator Light (MIL) (2 trip detection logic).




 
  #3  
Old 04-28-2016, 07:33 AM
hillhuggr's Avatar
Junior Member
Thread Starter
Join Date: Apr 2016
Posts: 2
Default A handful of Possibilities

According to that description, a P0172 has many possible causes. It's not going to be an easy fix. Guess I'll start by looking for air leaks and cleaning the MAF. Thanks
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
wrelkin123
Volkswagen Jetta/Bora
3
04-08-2014 08:17 PM
piyush123
Volkswagen Passat / CC
0
01-19-2011 11:44 PM
piyush123
Volkswagen Cabrio
0
11-24-2010 04:15 AM
MB77MONZA
General Tech
4
09-05-2008 12:21 PM
mrharmon10
PRIVATE For Sale / Trade Classifieds
0
04-24-2008 09:45 PM



Quick Reply: 2001 Eurovan - Diagnostics Help for a P0172 DTC



All times are GMT -5. The time now is 12:20 PM.