Checking for electrical voltage on the spark plugs can only be done with the spark plugs installed on the engine. Connect a 12 V test lamp between the spark plug terminal of the 4th cylinder and the "ground". Turn the ignition key to the "Heating" position (the help of a second person is required) and check if the indicator light comes on (see figure 262). If not, you need to disconnect the wire from the engine temperature sensor. Turn the ignition key to the "Heating" position (no more than 15 sec) — the indicator light should now light up. Then (if the indicator light is on):
- disconnect the wire and connecting bus from the spark plug;
- connect one clamp of the test lamp to the positive pole of the battery, and with the other one touch the ends of the starting plugs in turn. When the lamp lights up, the plug is in good condition.
No glow means the spark plug is faulty. A new spark plug is tightened to a torque of 40 Nm.
If the indicator lamp does not light:
- check the spark plug fuse and replace if necessary;
- if the fuse is OK, connect the test lamp to terminal "30" of the spark plug relay.
If the light comes on, it will indicate a faulty relay, which can be checked in the manner described below.
The absence of a glow means that there is a break in the circuit between terminal "30" of the relay and terminal "30" of the mounting block or the mounting block itself.
To check the spark plug relay, connect the test lamp to terminal "86" and set the "Heating" mode.
Light of the lamp will indicate a break in the connection of terminal "86" of the relay to the "ground" or terminal "87" to the fuse, or damage to the relay. No ignition of the lamp will indicate a break in the connection circuit of the mounting block to terminal "86" of the relay, or damage to the mounting block.
(The original article is available at: «VWmanual.ru»)
The positions of the relay terminals are shown in Figure 263.
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