Table of contents: Functional check ↓ Checking glow plugs (AMF, VNS) ↓ Checking glow plugs (aTL engine… ↓ Removal and installation glow plugs ↓
Instructions: The pre-glow system is controlled by the glow plug control unit "J179".
Used glow plugs "J179" have a self-diagnosis function. If the pre-glow system fails, an error is stored in the engine control unit. Used glow plugs "J179" are installed in the 3-slot relay board in the footwell on the front left in the 2-slot relay.
Functional check
Remove the plugs from the glow plugs. Connect the hand-held multimeter "VAG 1526C" to one of the plugs and to the engine ground. Select the actuator diagnostic mode and turn on the glow plug relay. Set value: approx. battery voltage (every 5 seconds). If the specified value is not reached: Eliminate possible open or short circuit in the wiring. Check the glow plug relay "J52". The diagnostic tester "VAS 5052" should be used.
Checking glow plugs (AMF, VNS)
Test conditions: battery voltage at least 11.5 volts. Switch off ignition. Remove plugs from glow plugs. Connect wire of LED test lamp using terminals from auxiliary and measuring tool set "VAG 1594 C" to positive terminal of battery (+). Install test probe of LED test lamp to each glow plug in turn. LED lights: glow plug is in good condition. LED does not light: remove and install glow plugs using 10 mm swivel wrench "VAS 3220". Place glow plug to be tested on fireproof surface. Connect glow plug pin to positive terminal of charged 12-volt battery. Connect glow plug thread to negative terminal of battery.
Instructions: To connect the glow plug, use wires with a minimum cross-section of 2.5 mm².
The wires must be equipped with stable terminals. Observe the glow plug glowing process. If the glow plug does not glow or only part of the pin glows, the glow plug should be replaced.
Checking glow plugs (aTL engine letter designation)
Instructions. On vehicles with the engine letter designation "ATL", the functioning and conductivity of the glow plugs should not be checked using a DC source (e.g. 12 Volt battery). There is a risk of damage to the glow plugs.
Removal and installation glow plugs
Disconnect the corresponding plug of the glow plug to be removed. Tightening torque: Glow plugs: 15 Nm.
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