Dodge Ram Truck 1500-2500-3500. Manual — part 186

PUMP MOTOR STALLED — 68

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BRAKES - ABS - ELECTRICAL DIAGNOSTICS

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PUMP MOTOR STALLED — 68 (CONTINUED)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Ignition on.

•

Set Condition:
When vehicle speed is above 15 MPH without ABS active. Vehicle speed above 4 MPH with a fault from the
previous ignition cycle. ABS pump motor command given and then turned off. High feedback voltage from the
low side of the motor continuously.

Possible Causes

ABS PUMP MOTOR INTERMITTENT DTC

FUSED B(+) CIRCUIT INTERMITTENTLY SHORTED TO GROUND

FUSED B(+) CIRCUIT SHORTED TO GROUND

FUSE OPEN - PUMP MOTOR CIRCUIT

NO B+ SUPPLY TO FUSE

ABS PUMP MOTOR INOPERATIVE

FUSED B(+) CIRCUIT OPEN

GROUND CIRCUIT OPEN

GROUND CIRCUIT HIGH RESISTANCE

CONTROLLER ANTI-LOCK BRAKE

Diagnostic Test

1.

DTC IS ACTIVE

Turn the ignition on.

With the DRBIII

T

, read DTC’s.

With the DRBIII

T

, erase DTC’s.

Turn the ignition off.

Turn the ignition on.

With the DRBIII

T

, actuate the ABS pump motor.

Did the Pump Motor operate when actuated?

Yes

>> Go To 10

No

>> Go To 2

2.

FUSE OPEN - PUMP MOTOR CIRCUIT

Turn the ignition off.

Remove and inspect the ABS Pump Motor fuse.

Is the Fuse open?

Yes

>> Go To 3

No

>> Go To 5

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PUMP MOTOR STALLED — 68 (CONTINUED)

3.

FUSED B(+) CIRCUIT INTERMITTENTLY SHORT

Ensure the Pump Motor connector is secure.

Visually inspect the Fused B(+) circuit in the wiring harness from the ABS PUMP fuse to the CAB harness connec-
tor. Look for any signs of an intermittent short to ground.

Is the wiring harness OK?

Yes

>> Go To 4

No

>> Repair as necessary.

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

4.

FUSED B(+) CIRCUIT SHORTED TO GROUND

Disconnect the CAB harness connector.

Ensure the ABS Pump Motor connector is secure.

Measure the resistance of the Fused B(+) circuit to ground.

Is the resistance above 5.0 ohms?

Yes

>> Replace the Controller Anti-Brake in accordance with the service manual. 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 Fused B(+) circuit short to ground.

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

5.

FUSED B(+) CIRCUIT OPEN

Remove the ABS PUMP Fuse.

Disconnect the CAB harness connector.

Measure the resistance of the Fused B (+) circuit between the ABS PUMP Fuse Terminal and the CAB harness
connector.

Is the resistance below 5.0 ohms?

Yes

>> Go To 6

No

>> Repair the open in the Fused B(+) circuit.

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

6.

NO B+ SUPPLY TO FUSE

Turn the ignition on.

Measure the voltage of the B(+) supply at the ABS PUMP Fuse terminal.

Is the voltage above 11 volts?

Yes

>> Go To 7

No

>> Repair the B(+) Supply circuit.

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

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PUMP MOTOR STALLED — 68 (CONTINUED)

7.

ABS PUMP MOTOR INOPERATIVE

Turn the ignition off.

Disconnect the ABS Pump Motor connector.

Connect a 10 gauge jumper wire between ABS Pump Motor Fused B(+) circuit and a 40 Amp Fused B(+) circuit.

Connect a 10 gauge jumper wire between ABS Pump Motor ground circuit and ground.

Monitor ABS Pump Motor operation.

Is the ABS Pump Motor operating?

Yes

>> Go To 8

No

>> Replace the ABS Pump Motor/Hydraulic Control Unit assembly.

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

8.

GROUND CIRCUIT OPEN

Turn the ignition off.

Disconnect the CAB harness connector.

Measure the resistance of the CAB Ground circuits.

Is the resistance below 5.0 ohms?

Yes

>> Go To 9

No

>> Repair the open in the Ground circuit.

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

9.

GROUND CIRCUIT HIGH RESISTANCE

Make sure the ABS Pump Motor connector is secure.

Turn the ignition on.

With the DRBIII

T

, enable ABS Pump Motor actuation.

NOTE: NOTE: ABS Pump Motor will not operate, but voltage will be applied.
Measure the voltage drop across the ABS Ground circuit connection, with ABS Pump Motor actuation enabled.

Is the voltage below 0.1 volt?

Yes

>> Replace the Controller Anti-Lock Brake in accordance with the service manual.

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

No

>> Repair the high resistance in the Ground circuit.

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

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