Dodge Ram Truck 1500-2500-3500. Manual — part 963

P1593-SPEED CONTROL SWITCH 1 STUCK (3.7L, 4.7L) (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.

•

Set Condition:
S/C Switch No.1 is mechanically stuck in the On/Off, Resume/Accel, or Set position for too long. One trip fault.

Possible Causes

(V37) S/C SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

(V37) S/C SIGNAL CIRCUIT OPEN

(K900) SENSOR GROUND OPEN

(V37) S/C SIGNAL CIRCUIT SHORTED TO GROUND

(V37) S/C SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND

SPEED CONTROL SWITCH

PCM

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

Diagnostic Test

1.

SPEED CONTROL SWITCH STATUS

Start the engine.

With a scan tool, monitor each which function for the Speed Control Switches.

Press and release each Speed Control Button.

- Resume/Accel

- Cancel

- Decel (Coast)

- On/Off

- Set

Does each switch function change status when pressing each switch?

Yes

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

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

No

>> Go To 2

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

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P1593-SPEED CONTROL SWITCH 1 STUCK (3.7L, 4.7L) (CONTINUED)

2.

SPEED CONTROL SWITCHES

Turn the ignition off.

Disconnect and remove the Speed Control Switches from the steering wheel per Service Information.

Measure the resistance across each Speed Control Switch.

Monitor the ohmmeter while pressing each function button on each switch.

Resume/Accel - 15.4 kohms

Cancel - 1.24 kohms

Coast - 2.94 kohms

On/Off -0.47 kohms

Set - 5.49 kohms

Does the function on the Speed Control Switches have the correct resistance value?

Yes

>> Go To 3

No

>> Replace the Speed Control Switch that had the incorrect resistance value.

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

3.

(V37) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Turn the ignition off.

Disconnect the C2 and C3 PCM harness connectors.

Measure the voltage of the (V37) S/C Switch No.1 Signal circuit in the
Speed Control harness connector.

Is the voltage above 5.0 volts?

Yes

>> Repair the short to battery voltage in the (V37) S/C Signal

No.1 circuit.

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

No

>> Go To 4

DR/DH

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

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P1593-SPEED CONTROL SWITCH 1 STUCK (3.7L, 4.7L) (CONTINUED)

4.

(V37) S/C SWITCH NO.1 SIGNAL CIRCUIT OPEN

NOTE: The measurement must be taken from both Speed Control
Switch harness connectors.
Turn the ignition off.

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 (V37) S/C Switch No.1 Signal circuit
from the Speed Control harness connector to the appropriate terminal
of special tool #8815.

Is the resistance below 5.0 ohms for both measurements?

Yes

>> Go To 5

No

>> Repair the open in the (V37) S/C Switch No.1 Signal cir-

cuit.

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

5.

(K900) SENSOR GROUND CIRCUIT OPEN

NOTE: The measurement must be taken from both Speed Control
Switch harness connectors.
Measure the resistance of the (K900) Sensor ground circuit from the
Speed Control harness connector to the appropriate terminal of special
tool #8815.

Is the resistance below 5.0 ohms for both measurements?

Yes

>> Go To 6

No

>> Repair the open in the (K900) Sensor ground circuit.

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

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

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P1593-SPEED CONTROL SWITCH 1 STUCK (3.7L, 4.7L) (CONTINUED)

6.

(V37) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO GROUND

Measure the resistance between ground and the (V37) S/C Switch
No.1 Signal circuit in the Speed Control harness connector.

Is the resistance below 100 ohms?

Yes

>> Repair the short to ground in the (V37) S/C Switch No.1

Signal circuit.

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

No

>> Go To 7

7.

(V37) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

Measure the resistance between the (V37) S/C Switch No.1 Signal cir-
cuit and the (K900) Sensor ground circuit in the Speed Control har-
ness connector.

Is the resistance below 5.0 ohms?

Yes

>> Repair the short between the (V37) S/C Switch No.1 Sig-

nal circuit and the (K900) Sensor ground circuit.

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

No

>> Go To 8

8.

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)

DR/DH

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

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