Understanding Diagnostic Information: Notes

NOTE: IFI control unit is referred to as N37 by the manufacturer. When diagnosing IFI, test connections are made at IFI control unit (N37) using Socket Box (129 589 00 21 00).

For reading and understanding fault code diagnosis, as an example, using DIAGNOSTIC TESTS, read fault code P1615. Start at step 1.0. Under TEST SCOPE column, component being tested is IFI control module (N3/7), voltage supply. Under TEST CONNECTION column, using DVOM, measure resistance between socket box terminals No. 19 and 37. Under TEST CONDITION column, make measurement with ignition on. Voltage is 11-14 volts under NOMINAL VALUE column. If voltage is within specification, go to next step (1.1). If voltage is not within specification, follow instructions under POSSIBLE CAUSE/REMEDY column. Replace relay module (K40) or repair faulty wiring.