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Connecting HHT/Impulse Counter - Reading/Erasing DTC Memory




NOTE: Observe all system specific instructions listed in the "Preparation for Test" section of each Test Program.

Hand Held Tester (HHT)
- Connect Hand-Held Tester (HHT) according to connection diagram below.

The following functions can be performed according to the instructions on the display:

a) Reading/erasing DTC memory
b) Reading actual values
c) Performing activations
d) Programming control modules

Diagnostic trouble codes (DTC's) which have been stored due to testing or the disconnection of lines must be erased from the diagnostic trouble code memory at the end of testing.

Special Tools:






Impulse Counter Scan Tool
- Connect Impulse counter Scan Tool according to connection diagram below.

LED "U-Batt" must light up in the display. If LED does not light up, check:

a) Voltage supply.
b) Impulse counter scan tool fuse.

1. Read Diagnostic Trouble code Memory

a) Ignition: ON
b) Press start button for 2 to 4 seconds.
c) Read and record diagnostic trouble code (DTC).
d) Press start button again for 2 to 4 seconds.
e) Read and record DTC.
Repeat steps d) and e) until the first DTC reappears.

NOTE: DTC readout is no longer possible using the impulse counter scan tool, with some systems, please review Section 12 in the "Diagnostic Procedures" section prior to starting the DTC readout.


2. Clear Diagnostic Trouble Code Memory 1)

a) Press start button for 2 to 4 seconds (DTC appears)
b) Wait 3 seconds, then press start button for 6 to 8 seconds, thereby erasing the previously displayed DTC from memory.
c) Each stored DTC must be erased individually.

1) Erasing of stored diagnostic trouble codes must begin within 20 seconds of reading the DTC. After 20 seconds, the DTC can no longer be erased. Erasing procedure can be restarted by performing DTC memory readout after the fault is again displayed.

Special Tools:






Connection Diagrams

38-pole Data Link Connector (X11/4):





Connect impulse counter scan tool as follows:
Red wire (circuit 30, voltage): socket 3
Black wire (circuit 31, ground): socket 1
Yellow wire to diagnostic output socket of the system being tested.


16-pole Data Link Connector (X11/4):





Connect HHT as follows:
Black wire (circuit 31, ground): socket 1
White wire (circuit 15, voltage): socket 16
Red wire (circuit 30): Battery + or X4/10
Yellow wire to diagnostic output socket of the system being tested.

Connect impulse counter scan tool as follows:
Black wire (circuit 31, ground): socket 1
Red wire (circuit 15, ignition): socket 16
Yellow wire to diagnostic output socket of the system being tested.


Connection Diagram:





087 Hand-Held Tester (HHT)
094 Multiplexer, 965 589 00 40
X11/4 Data link connector

Connect HHT as follows:
1. Connect HHT with Multiplexer (094) attached to Data link connector X11/4
2. Turn Ignition: ON
3. According to instructions in HHT display:
a) Readout DTC memory/erase
b) Readout Actual values
c) Perform Activations
d) Program control modules
4. Disconnect HHT.

NOTE: Observe all system specific instructions listed in the "Preparation for Test" section of the Test Program.
Diagnostic trouble codes (DTC's) which have been stored due to testing or the disconnection of lines must be erased from the diagnostic trouble code memory at the end of testing.


16-pole Data Link Connector (X11/4) - Model 163:





Connect HHT as follows:
1. Connect HHT with Multiplexer (094) and Adapter cable (107) attached, to Data link connector X11/4 (located in passenger compartment).
2. Turn Ignition: ON
3. According to instructions in HHT display:
a) Readout DTC memory/erase
b) Readout Actual values
c) Perform Activations
d) Program control modules
4. Disconnect HHT.

Note: Observe all system specific instructions listed in the "Preparation for Test" section of the Test Program.
Diagnostic trouble codes (DTC's) which have been stored due to testing or the disconnection of lines must be erased from the diagnostic trouble code memory at the end of testing.