List of checking procedures Check main relay * Pin 46 (main relay activation) must switch to U batt with a delay of 0.5 to 5 seconds after “ignition” is switched off. EHAB check S PWG max, engine running at upper idle speed S Interrupt voltage supply to EHAB (EDC pin 14), engine stops (max. 10 secs.) Check flashcode diagnosis: S Engine at idle speed; connect EDC pins 21 and 13 (short-circuit speed pickup) S EDC check lamp must come on (permanently illuminated); engine continues to run S Query flashcode (connect EDC pins 49 and 19 for at least 2 secs. or actuate diag- nosis button for at least 2 secs.
but not longer than 10 secs.) S Flashcode for “pickup defective” must be indicated (4 x brief flashes) or S Read out fault memory with MAN-Cats (defect in speed pickup momentarily pres- ent) S Disconnect pins 21 and 13 again S Delete fault memory: switch off ignition system, actuate diagnosis button, switch on ignition system, actuate button for at least 3 secs. but not longer than 10 secs Checking of capacity reserve of resonant circuit of control rod travel trans- mitter:
(Check only if the engine has general difficulties in starting) S Connect decade capacitor between pins 11 and 13 (on cable harness adapter) S Add auxiliary capacity until engine no longer starts and note down value S The capacity reserve of the resonant circuit of the control rod travel transmitter is to be at least 400 pF. If a Bosch cable harness adapter with approx. 100 pF is used, the set-point value of the additional capacity is to be > 300 pF. Deleting of fault memory After completion of the checks the fault memory must be deleted with MAN-Cats.
Once the ignition system has been switched on again there must be no fault stored; otherwise the fault must be traced and eliminated according to the troubleshooting plan. 28 PIN+ PIN– Set-point value [V] Measured value [V] Remark Main relay * 47 18 U-Batt . . . . . . . . . . . . . . Ignition sys. on 0 V . . . . . . . . . . . . . . Ignition sys. off 46 18 0 V . . . . . . . . . . . . . . Ignition sys. on _ _ U-Batt . . . . . . . . . . . . . . Ignition sys. off