Dodge Ram Truck 1500-2500-3500. Manual — part 1701

P0748-PRESSURE SOL CONTROL/TRANS RELAY CIRCUITS (GAS) (CONTINUED)

7.

CHECK THE (T118) GOVERNOR PRESSURE SOLENOID CONTROL CIRCUIT FOR A SHORT TO
ANOTHER CIRCUIT

Turn the ignition off to the lock position.

Remove the Transmission Control Relay.

Measure the resistance between the (T118) Governor Pressure Sole-
noid Control circuit and all other circuits in the Transmission Solenoid
Assembly harness connector.

Is the resistance below 5.0 ohms between the (T118) Governor
Pressure Solenoid Control circuit and any other circuit in the
Transmission Solenoid Assembly harness connector?

Yes

>> Repair the (T118) Governor Pressure Solenoid Control cir-

cuit for a short to another circuit(s).

Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)

No

>> Go To 8

8.

CHECK THE GOVERNOR PRESSURE SOLENOID

Remove the Transmission Oil Pan per the Service Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 48RE/FLUID - STANDARD PROCEDURE)

Check all internal wiring pertaining to the Governor Pressure Solenoid for an open, short, and bent or broken ter-
minals.

If no internal wiring problems are found, replace the Governor Pressure Solenoid per the Service Information. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/GOVERNOR PRESSURE SENSOR - REMOVAL)

Drive the vehicle performing multiple upshifts and downshifts.

With the scan tool, read Transmission DTCs.

Does the DTC reset?

Yes

>> Using the schematics as a guide, check the Powertrain Control Module (PCM) pins, terminals, and con-

nectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground
circuits. If no problems are found, replace and program the PCM per the Service Information. (Refer to
8

-

ELECTRICAL/ELECTRONIC

CONTROL

MODULES/POWERTRAIN

CONTROL

MODULE

-

REMOVAL)

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

No

>> Test Complete.

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

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AUTOMATIC TRANSMISSION - 48RE - GAS - ELECTRICAL DIAGNOSTICS

DR/DH

P0748-PRESSURE SOL CONTROL/TRANS RELAY CIRCUITS (GAS) (CONTINUED)

9.

CHECK THE FUSED B(+) CIRCUIT

Turn the ignition off to the lock position.

Remove the Transmission Control Relay.

Ignition on, engine not running.

Using a 12-volt test light connected to ground, check the Fused B(+)
circuit in the Transmission Control Relay connector.

Does the test light illuminate brightly?

Yes

>> Go To 10

No

>> Repair the Fused B(+) circuit for an open. If the fuse is

open, make sure to check for a short to ground.

Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)

10.

CHECK THE (T16) TRANSMISSION CONTROL RELAY OUTPUT CIRCUIT FOR A SHORT TO GROUND

Turn the ignition off to the lock position.

Disconnect the Transmission Solenoid Assembly harness connector.

Measure the resistance between ground and the (T16) Transmission
Control Relay Output circuit.

Is the resistance below 5.0 ohms?

Yes

>> Repair the (T16) Transmission Control Relay Output circuit

for a short to ground.

Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)

No

>> Go To 11

DR/DH

AUTOMATIC TRANSMISSION - 48RE - GAS - ELECTRICAL DIAGNOSTICS

21 - 737

P0748-PRESSURE SOL CONTROL/TRANS RELAY CIRCUITS (GAS) (CONTINUED)

11.

CHECK THE (T16) TRANSMISSION CONTROL RELAY OUTPUT CIRCUIT OPEN

Connect a jumper wire between Fused B(+) and the (T16) Transmis-
sion Control Relay Output circuit in the Transmission Control Relay
connector.

Ignition on, engine not running.

Using a 12-volt test light connected to ground, check the (T16) Trans-
mission Control Relay Output circuit in the Transmission Solenoid
Assembly harness connector.

Does the test light illuminate brightly?

Yes

>> Replace the Transmission Control Relay.

Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 48RE - STANDARD PROCEDURE)

No

>> Replace the (T16) Transmission Control Relay Output cir-

cuit for an open.

Perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCE-
DURE)

12.

INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.

Use the Freeze Frame Data to help duplicate the conditions in which the DTC originally set. Pay particular attention
to the DTC set conditions, such as, VSS, MAP, ECT, and Load

Using the schematics as a guide, visually inspect the related wiring harness. Look for any chafed, pierced, pinched,
or partially broken wires.

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

Wiggle the wiring and connectors while checking for any possible open or shorted circuits.

Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.

Were there any problems found?

Yes

>> Repair as necessary.

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

No

>> Test Complete.

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AUTOMATIC TRANSMISSION - 48RE - GAS - ELECTRICAL DIAGNOSTICS

DR/DH

P0751-O/D SWITCH PRESSED (LO) MORE THAN 5 MINUTES

DR/DH

AUTOMATIC TRANSMISSION - 48RE - GAS - ELECTRICAL DIAGNOSTICS

21 - 739