Checking the preheating system (VW Transporter T3)

If the engine starts poorly, it is necessary to check the operation of the automatic preheating system, as well as the warm-up system during starting.

1. After the preheating time has elapsed (the control light goes out) the voltage on the spark plugs should be maintained for another 6-7 seconds. Do not turn on the starter during this check. If there is no voltage on the spark plugs, replace the relay.

2. At startup (starter is on) there should be voltage on the spark plugs. If there is no voltage, restore the connection between the spark plug relay (terminal 50) and the relay board or replace the relay.

3. The connection diagram can be traced using the corresponding electrical diagram. Check the voltage supply

• (28-073) connect the test lamp between the spark plug of the 4th cylinder and the housing.
• remove the wire from the engine temperature sensor.
• turn the ignition key to the preheating position for no more than 15 seconds, the light should be on.
• reconnect the engine temperature sensor wire.

Preheating indicator does not work

(The original can be seen on the portal: vwmanual.ru)