Test 02 - Harness, Relays, Valves

ABS Test Equipment:

TEST SEQUENCE
1. Connections needed:
- T-plug (4a) with adapter (A) at ABS wire harness (1)
- Pull off overvoltage relay (3) and plug in bridge C
- Connecting lead from adapter (A) to cigarette lighter, red telltale lamp comes "On"
2. Switch position at adapter (A) on '3' model and test step 02 (right).





Nominal Values

3. Compare the displayed actual values obtained from the test equipment with the nominal values provided above. If nominal values are not obtained, proceed with the troubleshooting procedures below as needed.

TROUBLESHOOTING

NOTE: Turn "Off" ignition for single tests, control unit not connected.

Valve Relay Coil Resistance
- Check plug connections on hydraulic unit (plugs, relays). Replace valve relay.
- Measured value reading > 78 ohms: break in wire to valve relay. (from ignition switch, wire 27, wires in hydraulic unit)
- Measured value reading < 47 Ohms: short circuit in wire to valve relay. (wires 1 and 27, wires in hydraulic unit)

Motor Relay Coil Resistance
- Check plug connections on hydraulic unit (plugs, relays). Replace motor relay.
- Measured value reading > 58 Ohms: break in wire to motor relay. (from ignition switch, wire 28, wires in hydraulic unit)
- Measured value reading < 34 Ohms: short circuit in wire to motor relay. (wires 1 and 28, wires in hydraulic unit)

Valve Resistance
Specifications not reached on all three valves:
- First check wire 32 for break or short circuit. Pull off plugs on hydraulic unit.

Front Left
- Measure resistance direct on hydraulic unit between wires 1 and 4. Specification not reached:

Replace hydraulic unit.

- Check wire 2 from hydraulic unit plug to control unit plug for break or short circuit.

Front Right
- Measure resistance direct on hydraulic unit between wires 3 and 4. Specifications not reached:

Replace hydraulic unit.

- Check wire 35 from hydraulic unit plug to control unit plug for break or short circuit.

Rear
- Measure resistance direct on hydraulic unit between wires 5 and 4. Specifications not reached:

Replace hydraulic unit.

- Check wire 18 from hydraulic unit plug to control unit plug for break or short circuit.

(Rear Right)
- Measure resistance in wire harness adapter (4a), no measured value from car.

Repeat test with connected diagnosis plug for "wrong connection" display (better ground connection with tester.)