EuroVan 2.8L (Engine Code AES)

NOTE: Engine must be cold before performing test procedure.

Disconnect ECT sensor 2-pin connector. See Fig 3 . Using DVOM, measure resistance of ECT sensor between ECT sensor terminals No. 1 and 2. See ECT SENSOR (G62) RESISTANCE table. If ECT sensor resistance is okay, reconnect ECT sensor connector. Go to next step. If resistance is not okay, replace faulty ECT sensor. After repairs, erase DTC memory. Go to next step.
Verify battery voltage is a minimum of 11.5 volts and all fuses are okay. Repair as necessary. Connect scan tool. See DATA LINK CONNECTOR . Turn ignition on. Using scan tool, check ECT sensor temperature value. If ECT sensor temperature value deviates greatly from ECT sensor ambient temperature, go to step 4 . If ECT sensor temperature value is approximately the same as ECT sensor ambient temperature, go to next step.
NOTE: Next test step tests ECT sensor through its full range.

NOTE: Scan Tool VAG 1551/1552 and VAS 5051/5052 displays temperature in 1 to 1.5 degree increments.
Start engine and idle. Using scan tool, observe ECT sensor temperature value. Temperature value should steadily increase. If ECT sensor temperature value did not steadily increase, remove engine sound insulation cover. See Fig 1 . Check vacuum hose and coolant recirculating valve, recirculating valve should close when vacuum is applied. See Fig 2 . Repair as necessary. If repairs where made, erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE . If coolant recirculating valve is okay and temperature value did not steadily increase, replace faulty ECT sensor. Erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .
Disconnect ECM harness connector. Connect Test Box (VAG 1598/18) to ECM harness connector. See CONNECTING VAG TEST BOX . Disconnect ECT sensor 2-pin connector. See Fig 3 . Using DVOM, measure resistance between ECT sensor harness connector terminal No. 1 and test box socket No. 14. See Figure . Record resistance reading. Measure resistance between ECT sensor harness connector terminal No. 2 and test box socket No. 33. Record resistance reading. Resistance should be a maximum of 1.5 ohms for each reading. Go to next step.
Check ECT sensor harness connector terminal No. 2 of ECT for short circuit to test box socket No. 14. Check ECT sensor harness connector terminal No. 1 for short circuit to battery positive. Repair as necessary. If repairs where made, erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE . If wiring and ECT sensor are okay, replace faulty ECM. See ENGINE CONTROL MODULE REMOVAL under REMOVAL, OVERHAUL & INSTALLATION. After repairs, erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .