Notes on HHT for ME-SFI gasoline injection and ignition system - AD07.61-P-2000-04A
- Troubleshooting with HHT
Diagnostic trouble code memory: Select current fault
If the current status changes, e.g. due to a loose connector, the change is indicated visually and acoustically so that troubleshooting can take place immediately with the HHT.
- Loose contacts
Loose contacts are stored if they occur a number of times within a certain time interval. Therefore, they can only occur as stored faults and never as current faults.
- Specified values
All the specified values for the actual values displayed in the HHT are given in the engine diagnosis manual.
- Actual value for engine speed
For the engine speed, the idle speed specified value calculated by the control module is displayed on the left of the HHT display and the engine speed actual value is on the right.
The two values should only deviate slightly. The permissible tolerances have not been stipulated as yet.
- Version coding with HHT
- Before removing the ME-SFI control module, read out and save any available code numbers using HHT ("Version coding" menu item). After installing the new control module, input the stored code numbers.
If the new control module is returned to the parts warehouse, the code numbers must be deleted.
- If the code numbers cannot be read out, the automotive version must be determined, the corresponding code numbers taken from the parts microfilm, group 54, and entered manually using the HHT.
- Before removing the ME-SFI control module, read out and save any available code numbers using HHT ("Version coding" menu item). After installing the new control module, input the stored code numbers.
- Drive authorization system stage 2 (DAS)
After replacing the ME-SFI control module, version coding and then also the identification must be performed and the vehicle identification number entered (refer to HHT actual values for "Drive authorization system").
- Correction program
The following corrections can be made with the HHT:
(Refer to HHT menu item "Correction program")
- Correction of the ignition for various fuels (RON)
- Correction of the quantity of fuel in the case of complaints (MKV)
- Correction of the idle speed in selector lever position P/N
- Correction of the selector lever idle speed in driving gear
- CO-setting for vehicles without TWC (not for Model 638)
- Correction of the delay in the case of complaints
For Model 638: Electric suction-type fan for engine/AC
- Make fault setting conditions for irregular engine running recognition
less sensitive
For Model 638: correction of the delay in the case of complaints
- Desensitize the irregular engine running recognition