Dodge Ram Truck 1500-2500-3500. Manual — part 958

P1502-VEHICLE SPEED SENSOR 1/2 CORRELATION - NON DRIVE WHEELS (CONTINUED)

5.

VEHICLE SPEED SIGNAL CIRCUIT SHORTED TO GROUND

Measure the resistance between ground and the (B22) and (B222)
Vehicle Speed Signal circuits at the appropriate terminals of special
tool #8815.

Is the resistance below 100 ohms?

Yes

>> Repair the short to ground in the (B22) or (B222) Vehicle

Speed Signal circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Go To 6

6.

PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.

Were there any problems found?

Yes

>> Repair as necessary.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Replace and program the Powertrain Control Module per Service Information.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

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ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

DR/DH

P1572-BRAKE PEDAL STUCK ON

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

9 - 755

P1572-BRAKE PEDAL STUCK ON (CONTINUED)

For the Engine circuit diagram (Refer to 9 - ENGINE - SCHEMATICS AND DIAGRAMS).

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Ignition on. In plant mode only.

•

Set Condition:
PCM recognizes the Brake Pedal could not electrically indicate the applied (On) position with both switch
inputs. One trip fault.

Possible Causes

(B29) BRAKE SWITCH NO.1 SIGNAL CIRCUIT OPEN

(V32) BRAKE SWITCH NO.2 SIGNAL CIRCUIT OPEN

STOP LAMP SWITCH

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).

Diagnostic Test

1.

ACTIVE DTC

NOTE: Make sure the Stop Lamp Switch is adjusted properly before continuing.
Ignition on, engine not running.

With a scan tool, read DTCs.

Is the DTC active at this time?

Yes

>> Go To 2

No

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2.

STOP LAMP SWITCH OPERATION

Turn the ignition off.

Disconnect the Stop Lamp Switch harness connector.

Measure the resistance between the (Z429) Ground circuit terminal and the (B29) Brake Switch No.1 Signal terminal
in the Stop Lamp Switch.

Apply and release the brake pedal while monitoring the ohmmeter.

Does the resistance change from below 5.0 ohms to open circuit when pressing and releasing the brake
pedal switch?

Yes

>> Go To 3

No

>> Replace the Stop Lamp Switch.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

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ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

DR/DH

P1572-BRAKE PEDAL STUCK ON (CONTINUED)

3.

STOP LAMP SWITCH OPERATION

Measure the resistance between the (V30) Fused Igniton Switch Output terminal and the (V32) Brake Switch No.2
Signal circuit terminal in the Stop Lamp Switch.

Apply and release the brake pedal while monitoring the ohmmeter.

Does the resistance change from below 5.0 ohms to open circuit when pressing and releasing the Stop
Lamp switch?

Yes

>> Go To 4

No

>> Replace the Stop Lamp Switch.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

4.

(B29) BRAKE SWITCH NO.1 SIGNAL CIRCUIT OPEN

Disconnect the C3 PCM harness connector.

CAUTION: Do not probe the PCM harness connectors. Probing
the PCM harness connectors will damage the PCM terminals
resulting in poor terminal to pin connection. Install Miller Special
Tool #8815 to perform diagnosis.
Measure the resistance of the (B29) Brake Switch No.1 Signal circuit
from the Stop Lamp Switch harness connector to the appropriate ter-
minal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes

>> Go To 5

No

>> Repair the open in the (B29) Brake Switch No.1 Signal cir-

cuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

9 - 757