Test Step 3.1

Test 3.1:

Vehicle speed above 25 km/h: ABS lamp comes on, no ASC display, PALA ON:

Check 55-pin connector that it is firmly fitted and connected correctly at the ABS/ASC control unit.

Remove cover at hydraulic unit. Disconnect valve relay. Check valve relay, measure resistance between terminal No. 30 and No. 87 a (at relay) <1Ohm as well as at terminal No. 86 (-) to No. 85 (+) 12 V, relay clicks, resistance now between terminal No. 30 and No. 87 (at relay) <1 Ohm.

If necessary replace relay valve.

Resistance measurement:
at hydraulic unit:
Pin 2 to Pin 8 70 ... 100 Ohm
at 55-pin ABS/ASC control unit connector:
Pin 1 to Pin 27 70 ... 100 Ohm

Detach engine relay
Check engine relay:

At terminal No. 86 (-) to No. 85 (+) 12 V (at relay)
relay clicks, resistance now between terminal No. 30 and 87 <1 Ohm.
Replace engine relay.

Resistance measurement:
at hydraulic unit X31:
Pin 8 to Pin 2 34 ... 58 Ohm
at 55-pin ABS/ASC control unit X7:
Pin 23 to Pin 20 34 ... 58 Ohm

Diode measurement with BMW Service Tester:
at hydraulic unit:
Direction of flow
Pin 4 -> Pin 11
Blocking direction
Pin 11 <- Pin 4 Pin L1 to Pin 30 17 Ohm

at control unit:
Direction of flow
Pin 4 -> Pin 6 (see Operating Instructions BMW Service Tester)
Blocking direction
Pin 6 <- Pin 4