Test sequence

• Disconnect 4 pin connector from Engine Coolant Temperature Sensor -G62- with Engine Coolant Temperature Gauge Sensor - G2- -arrow -.
  NOTE: Disconnecting the ECT sensor connector simulates a "cold" engine condition and turning on ignition starts the glow plug process.
  Fig 1: Disconnecting ECT Sensor Connector

  
• Disconnect glow plug connector from glow plug.
• Connect multimeter VAG 1526 to measure voltage between No. 1 cylinder glow plug connector and vehicle ground. Then between cylinder No. 3 glow plug connector and vehicle ground. Specification:
• Switch on ignition.

Approx. battery voltage for 20 seconds

• If no voltage is present, check wiring.
• Check DTC memory, if necessary, repair any malfunctions and erase DTC memory. See DIAGNOSTIC TROUBLE CODE (DTC) MEMORY, CHECKING AND ERASING .
• Display readiness code. See READINESS CODE, DISPLAYING .
  NOTE: If DTC memory has been erased or Engine Control Module (ECM) was disconnected, reset readiness code. See READINESS CODE, SETTING .