With Manufacturer's Scan Tool
Throttle Valve Control Module -J338-, Adapting
The adaptation teaches Engine Control Module (ECM) various positions of throttle valve when ignition is on and engine is stopped. These positions are stored in control module The return communication regarding position of throttle valve occurs via two angle sensors for throttle drive.
An adaptation must always be performed when throttle valve control module -J338- or Engine Control Module (ECM) are removed and installed (or replaced) or if voltage supply to Engine Control Module (ECM) is interrupted.
The learning process (adaptation) occurs:
- Automatically if ignition is switched on for at least 6 seconds without operating starter and accelerator pedal and Engine Control Module (ECM) recognizes "adaptation required". (There will be no notification of whether adaptation was successful or not however). Adaptation required is recognized if stored voltage values from angle sensors do not match actual measured voltage values within a certain tolerance range.
- Via initiation of Basic Setting (function 04) display group 60 with ignition on.
NOTE: Engine will not start during automatic adaptation.
Special tools and equipment
- VAS5051 with VAG5051/1
Requirements
- No DTCs in DTC memory, check DTC memory.
- Engine not running, ignition switched on.
- Accelerator pedal not depressed.
- Coolant temperature 10 degree C to 95 degree C.
- Intake Air Temperature (IAT) 10 degree C to 90 degree C.
- Supply voltage for ECM larger than 12.7 V.
Procedure
- Connect vehicle diagnostic, testing and information system VAS 5051 and select vehicle system "01 -Engine electronics" in selection. Ignition must be switched on.
Display on VAS 5051:
- Under -1- select diagnostic function "04 - Basic setting".
Display on VAS 5051:
1 - Enter display group, max. entered value = 255
- Enter "060" for "display group number 060" in field -2- and confirm entry by pressing -Q- button.
After pressing the -Q- button, the throttle valve drive is initially connected without voltage present.
In this condition, the throttle valve is pulled into an emergency running position by a mechanical spring which is located in Throttle Valve Control Module -J338-. The values supplied by two angle sensors in this emergency running position are stored in Engine Control Module (ECM).
The throttle valve is then opened by a predetermined amount. When this value is reached, the throttle valve drive is again disconnected from voltage supply. The mechanical spring should then close throttle valve to previously learned emergency running position within a specified period of time (spring test).
The throttle valve drive then closes throttle valve; values supplied by angle sensors in Throttle Valve Control Module -J338- are stored in Engine Control Module (ECM).
If Engine Control Module (ECM) disconnects throttle valve drive from voltage supply while vehicle is being driven, the result will be an increased and fluctuating idling speed and a very poor throttle response.
Display on VAS 5051:
- Check specifications for Throttle Valve Control Module -J338- in display fields -3- and -4-.
**NOTE:
The control module can abort adaptation for the following reasons:
- The throttle valve cannot close completely (e.g. contamination).
- The battery voltage is too low.
- Throttle Valve Control Module -J338- or wire connection is faulty.
- Engine is started during adaptation or accelerator pedal is operated.
- Tension of throttle valve housing (check bolts).
When adaptation process is interrupted, message "Function is unknown or cannot be carried out at the moment" is displayed on tester. The next time the ignition is switched on (for several seconds), the adaptation process is automatically performed again.
- Exit function "04 - Basic setting" by pressing <- button.