NOTE: The DTC memory can only be read with the impulse counter scan tool only on vehicles up to Diagnosis Version 46. On vehicles as of Diagnosis Version 49, DTCs may only be read with the HHT. See Using Hand Held Tester .

Connect Impulse counter scan tool Data Link Connector (X11/4) according to connection diagram. See Figure . Connect the Yellow wire of the impulse counter scan tool to the diagnostic output socket of the system to be tested. See IMPULSE COUNTER DIAGNOSTIC OUTPUT SOCKET IDENTIFICATION table.
Turn ignition on. Press start button for 2-4 seconds. Read and record Diagnostic Trouble Code (DTC).
Press start button again for 2-4 seconds to read the next DTC.
Repeat step 3 until all DTC have been read.

NOTE: Clearing of DTC must begin within 20 seconds of reading the DTC. After 20 seconds, the DTC can no longer be cleared with out displaying that code again.

To clear a DTC, wait 3 seconds after DTC is displayed then press the start button for 6-8 seconds. Each DTC must be cleared individually.

IMPULSE COUNTER DIAGNOSTIC OUTPUT SOCKET IDENTIFICATION ⁽¹⁾

System To Be Tested

Diagnostic Output Socket No.

EA/CC/ISC

Engine Control Module (LH-SFI)

Diagnostic Module

Base Module

DI Module

⁽¹⁾	If diagnostic trouble code cannot be retrieved using the impulse counter scan tool. See Using Hand Held Tester .

Fig 1: Identifying Impulse Counter Scan Tool Special Tools

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Using Impulse Counter Scan Tool

Use the Manual With the Right Hardware

When to See a Mechanic

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