Dodge Ram Truck 1500-2500-3500. Manual — part 147

FOUNDATION BRAKE — 78 (CONTINUED)

5.

GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Using a 12–volt test light connected to 12 volts, check the Ground cir-
cuit.

NOTE: The test light should be illuminated and bright. Compare
the brightness to that of a direct connection to the battery.

Is the test light illuminated and bright?

Yes

>> Replace the Controller Anti-lock Brake in accordance with

the Service Information. Refer to the symptom *Replacing
the Controller Anti-lock Brake for additional information.

Perform ABS VERIFICATION TEST - VER 1. (Refer to 5 -
BRAKES/ELECTRICAL - DIAGNOSIS AND TESTING)

No

>> Repair the Brake Fluid Level Switch ground circuit for an

open circuit or high resistance.

Perform ABS VERIFICATION TEST - VER 1. (Refer to 5 -
BRAKES/ELECTRICAL - DIAGNOSIS AND TESTING)

6.

WIRING HARNESS INSPECTION

Turn the ignition off.

Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.

Visually inspect the related wire harness connectors. Look for broken, bent, pushed out, or corroded terminals.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes

>> Repair as necessary.

Perform ABS VERIFICATION TEST - VER 1. (Refer to 5 - BRAKES/ELECTRICAL - DIAGNOSIS AND
TESTING)

No

>> Test Complete.

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BRAKES - ABS - ELECTRICAL DIAGNOSTICS

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INTERMITTENT SIGNAL FROM LEFT FRONT SENSOR — 27

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BRAKES - ABS - ELECTRICAL DIAGNOSTICS

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INTERMITTENT SIGNAL FROM LEFT FRONT SENSOR — 27 (CONTINUED)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Ignition turned on for at least 3.5 seconds. Average filtered speed for the two front wheels above 6km/h
(4MPH). Speed for each suspect sensor above 32 km/h (20 MPH) (brake applied or ABS active) or 19 km/h
(12 MPH) (brake released or ABS inactive).

•

Set Condition:
When there is a sudden change of output signal from the sensor.

Possible Causes

INTERMITTENT LEFT FRONT WHEEL SPEED SENSOR DTC

LEFT FRONT WHEEL SPEED SENSOR (+) CIRCUIT SHORT TO GROUND

LEFT FRONT WHEEL SPEED SENSOR (-) CIRCUIT SHORT TO GROUND

LEFT FRONT WHEEL SPEED SENSOR (+) CIRCUIT OPEN

LEFT FRONT WHEEL SPEED SENSOR (-) CIRCUIT OPEN

LEFT FRONT WHEEL SPEED SENSOR (+) CIRCUIT SHORTED TO VOLTAGE

LEFT FRONT WHEEL SPEED SENSOR (-) CIRCUIT SHORTED TO VOLTAGE

LEFT FRONT WHEEL SPEED SENSOR (-) CIRCUIT SHORTED TO THE LEFT FRONT WHEEL SPEED
SENSOR (+) CIRCUIT

TONE WHEEL

EXCESSIVE LEFT FRONT WHEEL SPEED SENSOR AIR GAP

WHEEL BEARING

LEFT FRONT WHEEL SPEED SENSOR

CONTROLLER ANTI-LOCK BRAKE

Diagnostic Test

1.

DTC IS ACTIVE

Turn the ignition on.

With the DRBIII

T

, clear DTCs.

Turn the ignition off.

Turn the ignition on.

With the DRBIII

T

, read DTCs.

Does the DRBIII

T

display the DTC??

Yes

>> Go To 2

No

>> Go To 16

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BRAKES - ABS - ELECTRICAL DIAGNOSTICS

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INTERMITTENT SIGNAL FROM LEFT FRONT SENSOR — 27 (CONTINUED)

2.

CONTROLLER ANTI-LOCK BRAKE HARNESS CONNECTOR INSPECTION

Turn the ignition off.

Inspect the CAB wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.

Inspect the CAB wire harness connectors. Look for broken, bent, pushed out, or corroded terminals.

Were any problems found?

Yes

>> Clean or Repair as necessary in accordance with the Service Information.

Perform ABS VERIFICATION TEST - VER 1. (Refer to 5 - BRAKES/ELECTRICAL - DIAGNOSIS AND
TESTING)

No

>> Go To 3

3.

WHEEL SPEED SENSOR INSPECTION

Turn the ignition off.

Inspect the Wheel Speed Sensor for proper mounting.

Inspect the Wheel Speed Sensor harness and connector.

Inspect the Wheel Speed Sensor for excessive debris on the sensor.

Were any problems found?

Yes

>> Repair as necessary in accordance with the Service Information.

Perform ABS VERIFICATION TEST - VER 1. (Refer to 5 - BRAKES/ELECTRICAL - DIAGNOSIS AND
TESTING)

No

>> Go To 4

4.

TONE WHEEL DAMAGED/MISSING

Inspect the Tone Wheel in accordance with the Service Information.

NOTE: The Tone Wheel Teeth should be perfectly square, not bent or nicked.

Were any problems found?

Yes

>> Replace the Tone Wheel in accordance with the Service Information.

Perform ABS VERIFICATION TEST - VER 1. (Refer to 5 - BRAKES/ELECTRICAL - DIAGNOSIS AND
TESTING)

No

>> Go To 5

5.

EXCESSIVE WHEEL SPEED SENSOR AIR GAP

Measure the Wheel Speed Sensor Air Gap in accordance with the Service Information.

Were any problems found?

Yes

>> Repair as necessary in accordance with the Service Information.

Perform ABS VERIFICATION TEST - VER 1. (Refer to 5 - BRAKES/ELECTRICAL - DIAGNOSIS AND
TESTING)

No

>> Go To 6

DR/DH

BRAKES - ABS - ELECTRICAL DIAGNOSTICS

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