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99 jetta 2.0 can't perform basic setting on throttle adaption

Working on a 99 jetta with a 2.0L. It has a new rebuilt throttle body and also a second hand ecm. I can;t set throttle adaption under 98 of basic settings. I'am using Ross-Tech scanner. I've already ripped apart harness and all wiring looks OK. Under measuring block at closed throttle it says throttle is at 53.2% with the throttle closed. I beleave that is why I'am not able to perform adaptions. Already tried swapping throttle body and ecm. Any thouhts on what else I can check.Any help would be appreciated.Thanks

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Posted on Jan 02, 2017

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SOURCE: 2008 jetta trailer wiring

The wiring is behind the carpeting. It is not standard wiring, as the system operates on voltage differental, not separate filaments. It only uses one filament. Find a dedicated adapter and install it. This may be a job for a pro.

Posted on Nov 20, 2008

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SOURCE: '99 VW Jetta Cannot access ECM through DLC with

If there is an aftermarket radio in the car, unplug it. Sometimes those radios will interrupt the CAN signal & prevent the ECM from being accessed.

Posted on Jul 20, 2009

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SOURCE: 95 Jetta won't start weird buzzing sound near fuses

Jettas were notorious for electrical issues. I fought with one for 2 years.
The starter relay is on top of the starter in the center rear of the engine compartment near the firewall. Its mounted at the top of the bell housing, underneath the intake and next to the exhaust manifold and hard to get at from both the top and bottom. Personally, I'd take it to a good respectable foreign mechanic. Not worth fighting with

Posted on Jul 25, 2009

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SOURCE: 2004 jetta tdi, has engine miss & lack of

Running rough?? If i took a guess I'd say there's a faulty injector. Does it smoke like hell ?? Does it also miss at idle?- If so get a line wrench and a rag handy. Start the car and while idling wrap the rag around the base of the fuel line connector on injector 1 and crack it just a bit until fuel comes out. It might spray, thus the rag. If the miss gets worse, that ain't the injector to blame. Continue with the other 3. If you crack a line and there is no or very little change in the miss then you found the guilty party.

On a long shot it could also be a stuck valve.

Did that get it?? It sounds like an issue other than MAF but.... get a multimeter and try probing the connecter to the MAF. When you find out what it is , please let me know. I'm curious

*The key must be on*

pin 1- ignore it
pin 2- gnd = 12-14v
pins 2- 3 = 12-14v
pin 4- gnd = 5v
pins 3- 4 = 5v

P0101 - Mass Air Flow Sensor (G70): Implausible Signal

Possible Symptoms

  • Loss of Power
  • Erratic Idle
Possible Causes
  • Mass Air Flow Sensor (G70) faulty
  • Air Leak(s) after Mass Air Flow Sensor (G70)
  • Intake Air Filter dirty/faulty
  • Ground Spots corroded or Paint Residue
  • Wiring and/or Connections from/to Mass Air Flow Sensor (G70) faulty
Possible Solutions
  • Check Intake Air Filter
  • Check Mass Air Flow Sensor (G70)
  • Check Ground Spots
  • Check Wiring and/or Connections from/to Mass Air Flow Sensor (G70)

Posted on Dec 14, 2009

  • 632 Answers

SOURCE: 1997 Jetta GT 2.0 Stopped running,cranks,will not start

Checking for spark is really simple while fuel delivery is more complicated because of the the way it is metered for delivery. On VW's a fuel pump relay is used and a jumper cable connected to relay box. This controls the fuel pump to deliver fuel manually. With a fuel pressure gauge connected to the line from the pump continued withing the system, you assess whether you have correct fuel pressure, maintain it within a specif duration. Electronic fuel injectors do stick or stay open causing very poor or no start condition. Make sure you have fuel delivery since you are positive that spark is present.

Posted on May 30, 2010

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Code P1559?

P1559 - Throttle Body (J338): Fault in Basic Settings Possible Symptoms
  • Not known
Possible Causes
  • Idle Switch Open or Open Circuit
  • Throttle Valve sticks and won't close
  • Speed Impuls from Engine Speed Sensor (G28) recognized
Possible Solutions
  • Perform Throttle Body Adaptation

Mar 10, 2016 | 1996 Audi A4

3 Answers

I have a 98 jetta gls abs after it warms up it idles rough like rocking bacj and forth. When i pinch the fuel return line it gets better and the fuel pressure is at 30 psi. I work at goodyear and can't...

if pinching the fuel return line gives an improvement that there is not enough pressure at the injectors. This points to a fuel pressure regulator problem. Some are vacuum controlled so check that area first. Others may be electronic controlled so run fault codes to see if a fault has been recorded.

Dec 09, 2014 | 1998 Volkswagen Jetta

1 Answer

Truck dies when idling

first I would like to tell you, do this procedure only if the 5th digit of your VIN is C or K.


The engine control module (ECM) learns the idle position of the throttle plate to ensure the correct idle. Anytime the throttle body is cleaned or replaced, the ECM must learn the new throttle position. The idle may be unstable or a DTC may set if the throttle position is not learned.

Conditions for Running the Throttle Learn Procedure

• DTCs P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0506, and P0507 are not set.

• The engine speed is between 450-4,000 RPM.

• The manifold absolute pressure (MAP) is greater than 5 kPa.

• The mass air flow (MAF) is greater than 2 g/s.

• The ignition 1 voltage is greater than 10 volts.

Throttle Learn

Important: Do NOT perform this procedure if DTCs are set. Refer to Diagnostic Trouble Code

(DTC) List - Vehicle.

1. Start and idle the engine in PARK for 3 minutes.

2. With a scan tool, monitor desired and actual RPM.

3. The ECM will start to learn the new idle cells and Desired RPM should start to decrease.

4. Ignition OFF for 60 seconds.

5. Start and idle the engine in PARK for 3 minutes.

6. After the 3 minute run time the engine should be idling normal.

Important: During the drive cycle the check engine light may come on with idle speed DTCs. If idle speed codes are set, clear codes so the ECM can continue to learn.

* If the engine idle speed has not been learned the vehicle will need to be driven at

speeds above 70 km/h (44 mph) with several decelerations and extended idles.

7. After the drive cycle, the engine should be idling normally.

* If the engine idle speed has not been learned, turn OFF the ignition for 60 seconds

and repeat step 6.
8. Once the engine speed has returned to normal, clear DTCs.
Good Luck

Mar 04, 2014 | 1995 GMC Sierra

2 Answers

My engine light came up with the code p0068 & u0121, any one knows what should i do with that to fix it?

p0068 1. Clear all fault codes, remove intake boot using a rag that has been dampened with carb cleaner clean the throttle bore.

2. Using a full function VW compatible scan tool enter 01 engine management. From there, select basic settings enter block 060. This sets the throttle body adaptation.

3. Start the engine and using the scan tool select measured values, enter block 002 this will display the MAF sensor in gm's per second in field 4. At idle it should be 3 to 5 and at 2500 RPMs, it should be 9-15 and at WOT should be 90 or better. You posted 2 seperate issues. Please, one issue per posting.

Aug 15, 2012 | 2005 Volkswagen Jetta

1 Answer

After disconnected battery on 2000 A6, engine won't start or engine stay on for few seconds and then die off, noticing the fuel is being cut off, seem like the engine is in safe mode, if there is such.

On this cars , you need to use so called back up battery or memory saver , if you need to replace battery . If you need to perform some electrical work and battery has to be disconnected , then you better have a tool that capable of doing throttle body adaptation. Any time throttle body looses power , you have to do adaptation after, in order for it to work normaly.
Can not do it manually.(adaptation).

Jun 05, 2010 | 2000 Audi A6

2 Answers

Resetting throttlebody on 1998 be jetta glx

you can reset it by removing negative battery terminal while leaving positive terminal connected . open driver side door get in close door , put key in ignition turn over key almost all the way but do not start . you should here the throttle body aligning itself . leave key in this position for 15 seconds , remove key connect negative terminal and the throttle body should be set . this has been called the chicken dance and it works fine . what this does is resets the computer , key note though if you are planning to get your car inspected it will not pass until you have drove the car for at least 300 miles . being that the computer has to go through and set everything . i learned the hard way . throttle body problems usually happen when removing old battery improperly/battery being drained/improperly or jump starting the car/improperly , make sure when removing battery that the positive terminal is removed first , jumping a battery negative terminal is always connected first on both vehicles .

May 17, 2010 | 1998 Volkswagen Jetta

2 Answers

99 passat 2.8, vehicle was driven the night

That code is a Throttle Position Malfunction code.

This means one of two things:
1. The throttle body needs replaced
2. After the dead battery, you need to adapt the the throttle body.

The cheap way to do this is to leave the driver's door open, turn the key to the on position, but do not start the car. You will hear the throttle body self-adjust. This may take up to 2 minutes. That should get it close enough. To get it perfect requires a trip to the dealership.

If it does not help, the throttle body might be dead.

Dec 18, 2009 | 1999 Volkswagen Passat

1 Answer

Car keeps shutting off on me

try cleaning the throttle body and have the throttle position sensor checked.some throttle bodys need to have a basic setting performed with diagnostic machine.

Oct 12, 2009 | 1996 Volkswagen Jetta

1 Answer

2001 2.0 jetta manual tranny engine light on

Here are the test procedure for a PO171 code.

1. Check and verify there are no vacuum leaks or unmetered air leaks.

2. Check and verify air filter, all inlet screens and throttle body are clear and clean (never use an aerosol cleaner to clean a throttle body, damage to the throttle body electronics may result. Use a rag dampened with cleaner to wipe the throttle clean)

3. Check and verify fuel pressure is 36 PSI at idle with vacuum to the fuel pressure regulator.

4. Check Mass Airflow Sensor (MAF) Grams/Second (G/S) readings as follows:

Idle (about 830 RPM) 3.5 G/S or more (4 to 4.5 G/S preferred).

2500 RPM no load, 9 to 15 G/S (11 to 12 G/S preferred).

Wide Open Throttle (WOT) road load (drive vehicle at 45 MPH in 3rd gear and perform a WOT acceleration, observe maximum indicated MAF G/S readings) 90 or more G/S should be present, (prefer above 100 G/S).

A MAF that exhibits consistently lower than normal G/S readings can cause a P0171 code to set. Please let me know if this information is helpful. Positive feedback is appreciated. Thank You!

Mar 21, 2009 | 2001 Volkswagen Jetta TDI

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