Ford Falcon. Manual — part 83

206-09-21

Anti Lock Control

206-09-21

DIAGNOSIS AND TESTING (Continued)

Pinpoint Tests

PINPOINT TEST A : WHEEL SPEED SENSOR (WSS) CONTINUITY FAULT

NOTE: CODES C1145, C1155, C1165, C1175

Test Step

Result / Action to Take

A1

MEASURE THE RESISTANCE OF THE WSS AT THE

SENSOR CONNECTOR

Disconnect the WSS from the vehicle harness

Yes

Go to A2

Measure the resistance at the WSS connector terminals

No

Is the resistance between 1.28 & 1.92 K Ohms?

Replace faulty WSS and - Clear the DTC - Go to
ABS/TCS Diagnostic Procedure Table

A2

MEASURE THE RESISTANCE OF THE WSS AT THE

ABS ECU CONNECTOR

Reconnect the WSS to the vehicle harness

Yes

Go to A3

Disconnect the vehicle harness from the ABS ECU

No

Measure the resistance at the ECU connector terminals that

Locate high resistance fault in wiring and rectify

correspond to the WSS being checked

- Clear the DTC - Go to ABS/TCS Diagnostic

Is the resistance very close to that measured in A1?

Procedure Table

A3

CHECK THE VEHICLE WIRING

Check the wiring harness and all connections between the WSS and

Yes

the ABS ECU for permanent or intermittent open circuits or shorts. Be Repair or replace faulty wiring or connections -
sure to wiggle the wiring whilst testing

Clear the DTC - Go to ABS/TCS Diagnostic
Procedure Table

NOTE:

Never perform resistance check on ECU WSS output pins.

Always disconnect ECU before testing wiring harness and/or WSS

No

Clear the DTC - Go to ABS/TCS Diagnostic

Were any permanent or intermittent open circuits or shorts

Procedure Table

located?

or
If this is the second time that you have reached
this point (i.e. the same DTC has reappeared
after the first cycle of diagnostics/repair and the
and no faults were found) then the ECU may be
faulty. Replace the ABS/TCS modulator and
return to ABS/TCS Diagnostic Procedure Table
to confirm the repair.

PINPOINT TEST B : WHEEL SPEED SENSOR (WSS) OUTPUT FAULT

NOTE: CODES C1148, C1158, C1168, C1178, C1222

Test Step

Result / Action to Take

B1

CHECK THE AIR GAP BETWEEN THE WSS AND THE

TONE WHEEL

Measure the gap between the WSS and the tone wheel

Yes

Go to B2

Is the gap to specification?

No

Adjust as necessary - Clear the DTC - Go to
ABS/TCS Diagnostic Procedure Table

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206-09-22

Anti Lock Control

206-09-22

DIAGNOSIS AND TESTING (Continued)

Test Step

Result / Action to Take

B2

CHECK THE CONDITION OF THE TONE WHEEL

Visually inspect he tone wheel

Yes

Go to B3

Is the tone wheel free from damage (broken, deformed or
chipped) and does it have 50 teeth?

No

Replace the tone wheel and reset the air gap to
specification - Clear the DTC - Go to ABS/TCS
Diagnostic Procedure Table

B3

CHECKING WHEEL SPEED OUTPUT USING AN

OSCILLOSCOPE.

Viewing of Oscilloscope Patterns (WSS.)

Yes

Go to A1

Disconnect the vehicle harness from the ABS ECU.
Set the WDS to read oscilloscope wave patters.

No

Investigate and rectify cause of fault - Clear the

Check the oscilloscope pattern at the ECU connector

DTC - Go to ABS/TCS Diagnostic Procedure

terminals that correspond to the WSS being checked.

Table

Raise the vehicles wheels off the ground and rotate to
achieve the below patters.

Simulated normal oscilloscope pattern:

Simulated pattern showing possible increasing and

decreasing distance between WSS and pulse wheel:

Simulated pattern showing possible chipped or

damaged teeth:

NOTE:

When using an oscilloscope to check the WSS output, the

wheel must be rotated at a constant speed.
Incorrect wheel bearing clearance can cause inaccurate readings.

Does the oscilloscope pattern look similar to the above normal
pattern?

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206-09-23

Anti Lock Control

206-09-23

DIAGNOSIS AND TESTING (Continued)

PINPOINT TEST C : LOW/HIGH VOLTAGE FAILURE

NOTE: CODES - B1317, B1318

Test Step

Result / Action to Take

C1

CHECK VOLTAGE AT THE BATTERY

Check the battery voltage

Yes

Go to C2

Check battery charging voltage (Refer to Alternator test procedure)

No

Is the battery voltage to specification?

Repair as required - Clear DTC - Go to
ABS/TCS Diagnostic Procedure Table

C2

CHECK VOLTAGE AT THE ABS ECU CONNECTOR –

TERMINALS 17 & 18

Disconnect the vehicle harness from the ABS ECU

Yes

Go to C3

Check the voltage at terminals 17 & 18 (Check voltage across each
terminal to ground)

No

Check corresponding fuses, wiring connections

Is the voltage at terminals 17 & 18 constant battery voltage

and looms for open circuits or shorts to ground.

regardless of ignition position?

Be sure to wiggle the wiring whilst testing and
repair as required - Clear the DTC - Go to
ABS/TCS Diagnostic Procedure Table

C3

CHECK VOLTAGE AT THE ECU CONNECTOR -

TERMINAL 15

Check the voltage at terminal 15 (Check voltage across each terminal

Yes

to ground)

Go to C4

Is the voltage at terminals 15 constant battery voltage with

No

ignition ON?

Check corresponding fuses, wiring connections
and looms for open circuits or shorts to ground.
Be sure to wiggle the wiring whilst testing and
repair as required - Clear the DTC - Go to
ABS/TCS Diagnostic Procedure Table

C4

CHECK CONTINUITY AT THE ECU CONNECTOR -

TERMINAL 16 & 19

Check the resistance at terminals 16 & 19 (Check resistance between

Yes

each terminal and ground)

Repair as required - Clear the DTC - Go to
ABS/TCS Diagnostic Procedure Table

Is there a high resistance or open circuit between terminals 16 &
19 and ground

No

Clear the DTC - Go to ABS/TCS Diagnostic
Procedure Table
or
If this is the second time that you have reached
this point (i.e. the same DTC has reappeared
after the first cycle of diagnostics/repair and the
and no faults were found) then the ECU may be
faulty. Replace the ABS/TCS modulator and
return to ABS/TCS Diagnostic Procedure Table
to confirm the repair.

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206-09-24

Anti Lock Control

206-09-24

DIAGNOSIS AND TESTING (Continued)

PINPOINT TEST D : BRAKE LIGHT SWITCH FAILURE

NOTE: CODES - P1571

Test Step

Result / Action to Take

D1

CHECK THE BRAKE LIGHTS

Check the brake lights

Yes

Go to D2

Do the brake lights work?

No

Check the following. Repair as required. Clear
DTC. Go to ABS/TCS Diagnostic Procedure
Table.
Check for voltage supply at the brake light
switch
Check the operation and adjustment of the
brake light switch
Check for blown bulbs, open circuits or shorts in
the wiring from the brake light switch to the
brake lights. Be sure to wiggle the wiring whilst
testing.

D2

CHECK VOLTAGE AT THE ECU CONNECTOR -

TERMINAL 14

Disconnect the vehicle harness from the ABS ECU.

Yes

Clear the DTC - Go to ABS/TCS Diagnostic

Check the voltage at terminal 14 (Check voltage across each terminal Procedure Table

to ground)

or
If this is the second time that you have reached

Does terminal 14 have >10V when the brakes are applied?

this point (i.e. the same DTC has reappeared
after the first cycle of diagnostics/repair and the
and no faults were found) then the ECU may be
faulty. Replace the ABS/TCS modulator and
return to ABS/TCS Diagnostic Procedure Table
to confirm the repair.

No

Check for open circuits or shorts in the wiring
from the brake light switch to the ABS/TCS
ECU. Be sure to wiggle the wiring whilst testing -
Repair as required - Clear DTC - Go to
ABS/TCS Diagnostic Procedure Table

PINPOINT TEST E : ABS/TCS MODULATOR ASSEMBLY INTERNAL FAULT

NOTE: CODES - C1342, C1266, C1095

Test Step

Result / Action to Take

E1

CHECK VOLTAGE AT THE ABS ECU CONNECTOR –

TERMINALS 17 & 18

Disconnect the vehicle harness from the ABS ECU

Yes

Go to E2

Check the voltage at terminals 17 & 18 (Check voltage across each
terminal to ground)

No

Check corresponding fuses, wiring connections

Is the voltage at terminals 17 & 18 constant battery voltage

and looms for open circuits or shorts to ground.

regardless of ignition position?

Be sure to wiggle the wiring whilst testing and
repair as required - Clear the DTC - Go to
ABS/TCS Diagnostic Procedure Table

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