DTC 1-5-1 L/H Front Wheel Sensor, Open Or Short To Supply

CONDITIONS FOR DTC
If there are no signals from the sensor, because there is an open-circuit or short-circuit to + in the lead or sensor, the control module will record the fault and post a DTC. The DTC will be posted even with the car at a standstill and the ignition off.

SYMPTOMS
ABS warning light on, ABS system not working.

SOURCES OF FAULT
Open-circuit in sensor or lead, or short-circuit to supply (12 volts).

CHECKING VOLTAGE
1. Ignition off.
2. Connect test box between control module and ABS connector.
3. Jack car up so wheel is free to turn
4. Connect a voltmeter (set to AC) across the test box connections as follows: LH front wheel, # 4 (0 volts) and # 6
5. Ignition on.
6. Turn the wheel concerned by hand.

NOTE: when checking rear wheel sensor, make sure one wheel is locked.

7. Voltmeter reading should vary between 0 and 2 volts, depending on speed of wheel. At low wheel speeds, meter should read approx. 500 mV.

IF READING IS INCORRECT
^ Voltmeter reading stays around 5 volts DC. This means there is an open-circuit in a lead somewhere or that the sensor is faulty. Go below to Checking lead resistance.
^ If voltmeter reading stays at battery voltage, this means there is a short-circuit to +. Go below to Checking short-circuit to +.

CHECKING LEAD RESISTANCE
1. Ignition off.
2. Disconnect control module from adapter.
3. Disconnect connector from sensor concerned.
4. Bridge terminals 1 and 2 on lead connector (female contact).
5. Using an ohmmeter, measure across test box terminals as follows: LH front wheel, # 4 (0 volts) and 6
6. Ohmmeter reads 0 ohms: Lead is OK; go below to Checking sensor resistance.

IF READING IS INCORRECT
Go to step Checking lead for open-circuit.

CHECKING SENSOR RESISTANCE
1. Ignition off.
2. Disconnect connector from sensor.
3. Connect an ohmmeter across sensor pins 1 and 2.
4. Ohmmeter should read approx.: LH front wheel, 1 ohm

IF READING IS INCORRECT
If ohmmeter reading sticks at infinity, there is an open circuit in the sensor. Replace sensor. Check DTCs after action.

CHECKING LEAD FOR OPEN-CIRCUIT
1. Ignition off.
2. Disconnect sensor.
3. Connect test box to ABS connector.
4. Using an ohmmeter, measure between the connector for the wheel concerned (male contact) and test box as below, Checking signal ground, Checking signal lead.

CHECKING SIGNAL GROUND
Connector, LH wheel housing tower, terminal 2 and test box # 4. Ohmmeter reading should be approx. 0 ohms. Go to Checking signal lead.

IF READING IS INCORRECT
Open-circuit in lead. Fix needed repair. Check DTC after repair.

CHECKING SIGNAL LEAD
Connector LH wheel housing tower, terminal 1 and test box # 6. Ohmmeter reading should be about 0 ohms.

IF READING IS INCORRECT
Open-circuit in signal lead. Fix needed repair. Check DTC after action.

CHECKING SHORT-CIRCUIT TO +
1. Ignition off.
2. Disconnect lead from battery positive terminal.
3. Undo connector from sensor concerned.
4. Connect an ohmmeter between the sensor lead connector and battery positive lead. Front wheel sensor, pin 1.
5. Ohmmeter reading should be high (some ohms or infinite resistance).

IF READING IS INCORRECT
If ohmmeter reading is approx. 0 ohms or just a few ohms; there is a short-circuit to +. Repair with short-circuit. Check DTC after action.