A. Engine 104 / 111 Model Years 93/94 With HFM - SFI
Subject A Is divided Into the following sections:Testing with Diagnostic Engine Analyzers
^ Bear DACE, Hermann Engine Analyzers D950/960S/980
Testing with Engine Analyzers (Non-Diagnostic)
^ Sun MEA 15OO MB (using DIA-2MB adapter)
^ Bear DACE, Sun MEA 15OO, Sun MCM 2110 (without the use of the test adapters)
Testing with Diagnostic Engine Analyzers
For maximum diagnostic capability when trouble shooting Mercedes Benz vehicles we strongly recommend using the diagnostic engine analyzer. The diagnostic analyzer is directly connected to the secondary ignition circuit and is not limited in test capabilities as is the standard, non-diagnostic engine analyzer, which must be connected to the primary ignition circuit in order to diagnose the secondary side.
^ Bear DACE, Hermann Engine Analyzers D950/960S/980
Due to the elimination of the TDC sensor, ignition timing should be checked with the Hand-Held Tester (HHT) OR with the timing light from the diagnostic engine analyzer. Furthermore, testing of the O2 sensor is only possible using the HHT.
Use only test adapters which are approved by MBNA and the manufacturer of the engine analyzer (e.g. Automotive Diagnostics).
Only with proper test adapters can the maximum diagnostic potential of the engine analyzer be utilized. Along with the standard engine tests, diagnostic tests such as dynamic compression test, idle quality and ignition analysis can be performed with the test adapters e.g.:
Electronic Ignition (EI) distributor-less adapter (ref: CD 1222 BA) for Bear DACE.
Connection method and test procedures:
Refer to manufacturer's operating manual.
Testing with Engine Analyzers (Non-Diagnostic)
The non-Diagnostic engine analyzer must only be used in the event a diagnostic engine analyzer is not available. The non-diagnostic analyzer's test capabilities are limited when compared to a diagnostic analyzer.
^ Sun MEA 1500 MB engine analyzer (using DIA-2MB adapter)
The Distributer-less Ignition Adapter, DIA-2MB, is used in conjunction with the SUN MEA 1500 MB engine analyzer and is connected to the primary side of the ignition circuit. Evaluation of the secondary ignition circuit (output side of the coil) is possible by evaluating the signals of the primary ignition circuit (input side of the coil). Only ignition related faults can be detected.
When the Sun MEA 1500 MB engine analyzer is connected to the primary ignition circuit, an evaluation of the ignition spark burn time, start of combustion and decay characteristics of the secondary circuit can be performed.
The secondary ignition voltage cannot be directly measured from the primary circuit since the voltage induced into the primary winding by the secondary winding is limited by the output stage in the engine control module (Zener voltage). However, a fault in the secondary ignition circuit, e.g. a defective spark plug connector does have an effect on the start point of combustion and on the burn time of the ignition spark, which can be recognized in the primary oscilloscope image. Therefore, in order to analyze the secondary ignition circuit, the primary oscilloscope image must first be analyzed in the parade pattern and afterwards in the individual image pattern with a 5 or 25 millisecond time base.
Connection method and test procedures:
Refer to Sun Operating Instructions.
^ Bear DACE and Sun MCM 211O/MEA 1500 (without the use of test adapters) The ignition system used in the HFM-SFI system can be checked by connecting the Mercedes-Benz socket box to the engine HFM-SFI engine control module and then connecting the universal engine analyzer leads to the socket box.
Evaluation of the secondary ignition circuit (output side of the coil) is possible by evaluating the signals of the primary ignition circuit (input side of the coil). Only ignition related faults can be detected. When the engine analyzer is connected to the primary ignition circuit, an evaluation of the ignition Spark burn time, start of combustion and decay characteristics of the secondary circuit can be performed. The secondary ignition voltage cannot be directly measured from the primary circuit since the voltage induced into the primary winding by the secondary winding is limited by the Output stage in the engine control module (Zener voltage). However, a fault in the secondary ignition circuit, e.g. a defective spark plug connector does have an effect on the start point of combustion and on the burn time of the ignition spark, which can be recognized in the primary oscilloscope image.
Therefore, in order to analyze the secondary circuit, the primary oscilloscope image must first be analyzed in the parade pattern and afterwards in the individual image pattern with a 5 or 25 millisecond time base.
Connection method (without use of test adapter unit) and test procedures:
Set engine analyzer to cylinders =2 and primary display and test the circuits one at a time. Do not clip the kilovolt and trigger clamp (refer to tables below for socket box connections).
Engines 111/104 HFM-SFI
Engine 104 HFM-SFI
Engine 111 HFM-SFI