Page 4209 of 4284

TEST ACTION APPLICABILITY
2 With the DRBIIIt, read Transmission DTC's
Are there any Transmission Control Relay related DTC's P1765, 1767, or 1768
present?All
Ye s®Refer to symptom list and perform the appropriate test for
Transmission Relay related DTC's.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 3
3 With the DRBIIIt, Check the STARTS SINCE SET counter.
NOTE: This counter only applies to the last DTC set.
Is the STARTS SINCE SET counter 2 or less for P1781?All
Ye s®Go To 4
No®Go To 11
4 Turn the ignition off to the lock position.
CAUTION: Remove the Starter Relay from the IPM. This will prevent the
vehicle from being started in gear.
Install Transmission Simulator, Miller tool #8333 and the FWD Adapter Cable kit,
Miller tool #8333-1.
Note: Check connectors - Clean/repair as necessary.
Ignition on, engine not running.
On the Transmission Simulator select OD on the Pressure Switch selector switch.
With the DRBIIIt, monitor the OD Pressure Switch state while pressing the
Pressure Switch Test button on the Transmission Simulator.
Did the Pressure Switch state change from OPEN to CLOSED when the test button
was pressed?All
Ye s®Go To 5
No®Go To 6
5 If there are no possible causes remaining, view repair. All
Repair
Replace Transmission Solenoid/Pressure Switch Assembly per the
Service Information.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
6 Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Remove the Transmission Control Relay from the IPM.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between the Fused B+ circuit and the Transmission Control
Relay Output circuit in the Transmission Control Relay connector in the IPM.
Using a 12-volt test light connected to ground, check the Transmission Control Relay
Output circuit in the Solenoid/Pressure Switch Assembly harness connector.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s®Go To 7
No®Repair the Transmission Control Relay Output circuit for an open
or high resistance.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
105
TRANSMISSION
P1781-OD PRESSURE SWITCH SENSE CIRCUIT ÐContinued
Page 4210 of 4284

TEST ACTION APPLICABILITY
7 Turn the ignition off to the lock position.
Disconnect the TCM harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Note: Check connectors - Clean/repair as necessary.
Measure the resistance of the O/D Pressure Switch Sense circuit from the TCM
harness connector to the Transmission Solenoid/Pressure Switch Assembly harness
connector.
Is the resistance above 5.0 ohms?All
Ye s®Repair the O/D Pressure Switch Sense circuit for an open.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 8
8 Turn the ignition off to the lock position.
Disconnect the TCM harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Note: Check connectors - Clean/repair as necessary.
Measure the resistance between ground and the O/D Pressure Switch Sense circuit.
Is the resistance below 5.0 ohms?All
Ye s®Repair the O/D Pressure Switch circuit for a short to ground.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 9
9 Turn the ignition off to the lock position.
Disconnect the TCM harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Remove the Transmission Control Relay from the IPM.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between the Fused B+ circuit and the Transmission Control
Relay Output circuit in the Transmission Control Relay connector in the IPM.
Ignition on, engine not running.
Measure the voltage of the O/D Pressure Switch Sense circuit in the TCM harness
connector.
Is the voltage above 0.5 volt?All
Ye s®Repair the O/D Pressure Switch Sense circuit for a short to
voltage.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 10
10 If there are no possible causes remaining, view repair. All
Repair
Replace the TCM. WITH THE DRBIIItPERFORM QUICK
LEARN AND REPROGRAM PINION FACTOR.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
11 The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this
circuit.
Wiggle the wiring while checking for shorts and open circuits.
Were there any problems found?All
Ye s®Repair as necessary.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Test Complete.
106
TRANSMISSION
P1781-OD PRESSURE SWITCH SENSE CIRCUIT ÐContinued
Page 4211 of 4284

Symptom:
P1782 - 2-4 PRESSURE SWITCH SENSE CIRCUIT
When Monitored and Set Condition:
P1782 - 2-4 PRESSURE SWITCH SENSE CIRCUIT
When Monitored: Whenever the engine is running.
Set Condition: The appropriate DTC is set if one of the Pressure Switches are open or
closed at the wrong time in a given gear .
POSSIBLE CAUSES
TRANSMISSION RELAY DTC'S PRESENT
INTERMITTENT WIRING AND CONNECTORS
TRANSMISSION RELAY OUTPUT CIRCUIT OPEN
2/4 PRESSURE SWITCH SENSE CIRCUIT OPEN
2/4 PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
2/4 PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
2/4 PRESSURE SWITCH
TCM - 2/4 PRESSURE SWITCH CIRCUIT
TEST ACTION APPLICABILITY
1NOTE: Low fluid level can be the cause of many Transmission problems. If
the fluid level is low locate and repair the leak then check and adjust the
fluid level per the Service Information.
NOTE: Always perform diagnostics with a fully charged battery to avoid
false symptoms.
With the DRBIIIt, read the engine DTC's. Check and repair all engine DTC's prior
to performing Transmission Symptom Diagnostics.
With the DRBIIIt, read Transmission DTC's. Record all DTC's and 1 Trip Failures.
NOTE: Diagnose 1 Trip Failures as a fully matured DTC.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
Repair as necessary.
Perform the Shift Lever Position Test. If the test does not pass, refer to Symptom test
for P0705 Check Shifter Signal.
For Gear Ratio DTC's, check and record all CVI's.
Most DTC's set on start up but some must be set by driving the vehicle such that all
diagnostic monitors have run.
NOTE: Verify flash level of Transmission Control Module. Some problems
are corrected by software upgrades to the Transmission Control Module.
NOTE: Check for applicable TSB's related to the symptom.
Perform this procedure prior to Symptom diagnosis.All
Continue
Go To 2
107
TRANSMISSION
Page 4212 of 4284

TEST ACTION APPLICABILITY
2 With the DRBIIIt, read Transmission DTC's
Are there any Transmission Control Relay related DTC's P1765, 1767, or 1768
present?All
Ye s®Refer to symptom list and perform the appropriate test for
Transmission Control Relay related DTC's.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 3
3 With the DRBIIIt, Check the STARTS SINCE SET counter.
NOTE: This counter only applies to the last DTC set.
Is the STARTS SINCE SET counter 2 or less for P1782?All
Ye s®Go To 4
No®Go To 11
4 Turn the ignition off to the lock position.
CAUTION: Remove the Starter Relay from the IPM. This will prevent the
vehicle from being started in gear.
Install Transmission Simulator, Miller tool #8333 and the FWD Adapter Cable kit,
Miller tool #8333-1.
Note: Check connectors - Clean/repair as necessary.
Ignition on, engine not running.
On the Transmission Simulator select 2/4 on the Pressure Switch selector switch.
With the DRBIIIt, monitor the 2/4 Pressure Switch state while pressing the Pressure
Switch Test button on the Transmission Simulator.
Did the Pressure Switch state change from OPEN to CLOSED when the test button
was pressed?All
Ye s®Go To 5
No®Go To 6
5 If there are no possible causes remaining, view repair. All
Repair
Replace Transmission Solenoid/Pressure Switch Assembly per the
Service Information.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
6 Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Remove the Transmission Control Relay from the IPM.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between the Fused B+ circuit and the Transmission Control
Relay Output circuit in the Transmission Control Relay connector in the IPM.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, check the Transmission Control Relay
Output circuit in the Solenoid/Pressure Switch Assembly harness connector.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s®Go To 7
No®Repair the Transmission Control Relay Output circuit for an open
or high resistance.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
108
TRANSMISSION
P1782 - 2-4 PRESSURE SWITCH SENSE CIRCUIT ÐContinued
Page 4213 of 4284

TEST ACTION APPLICABILITY
7 Turn the ignition off to the lock position.
Disconnect the TCM harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Note: Check connectors - Clean/repair as necessary.
Measure the resistance of the 2/4 Pressure Switch Sense circuit from the TCM
harness connector to the Transmission Solenoid/Pressure Switch Assembly harness
connector.
Is the resistance above 5.0 ohms?All
Ye s®Repair the 2/4 Pressure Switch Sense circuit for an open.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 8
8 Turn the ignition off to the lock position.
Disconnect the TCM harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Note: Check connectors - Clean/repair as necessary.
Measure the resistance between ground and the 2/4 Pressure Switch Sense circuit.
Is the resistance below 5.0 ohms?All
Ye s®Repair the 2/4 Pressure Switch Sense circuit for a short to ground.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 9
9 Turn the ignition off to the lock position.
Disconnect the TCM harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Remove the Transmission Control Relay from the IPM.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between the Fused B+ circuit and the Transmission Control
Relay Output circuit in the Transmission Control Relay connector in the IPM.
Ignition on, engine not running.
Measure the voltage of the 2/4 Pressure Switch Sense circuit in the TCM harness
connector.
Is the voltage above 0.5 volt?All
Ye s®Repair 2/4 Pressure Switch Sense circuit for a short to voltage.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 10
10 If there are no possible causes remaining, view repair. All
Repair
Replace the TCM. WITH THE DRBIIItPERFORM QUICK
LEARN AND REPROGRAM PINION FACTOR.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
11 The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this
circuit.
Wiggle the wiring while checking for shorts and open circuits.
Were there any problems found?All
Ye s®Repair as necessary.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Test Complete.
109
TRANSMISSION
P1782 - 2-4 PRESSURE SWITCH SENSE CIRCUIT ÐContinued
Page 4214 of 4284

Symptom:
P1784-LR PRESSURE SWITCH SENSE CIRCUIT
When Monitored and Set Condition:
P1784-LR PRESSURE SWITCH SENSE CIRCUIT
When Monitored: Whenever the engine is running.
Set Condition: The appropriate DTC is set if one of the Pressure Switches are open or
closed at the wrong time in a given gear .
POSSIBLE CAUSES
LOSS OF PRIME DTC P1791 PRESENT
TRANSMISSION CONTROL RELAY DTCS PRESENT
TCM AND WIRING - L/R PRESSURE SWITCH
INTERMITTENT WIRING AND CONNECTORS
TRANSMISSION RELAY OUTPUT CIRCUIT OPEN
L/R PRESSURE SWITCH SENSE CIRCUIT OPEN
L/R PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
L/R PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
TCM - L/R PRESSURE SWITCH CIRCUIT
TEST ACTION APPLICABILITY
1NOTE: Low fluid level can be the cause of many Transmission problems. If
the fluid level is low locate and repair the leak then check and adjust the
fluid level per the Service Information.
NOTE: Always perform diagnostics with a fully charged battery to avoid
false symptoms.
With the DRBIIIt, read the engine DTC's. Check and repair all engine DTC's prior
to performing Transmission Symptom Diagnostics.
With the DRBIIIt, read Transmission DTC's. Record all DTC's and 1 Trip Failures.
NOTE: Diagnose 1 Trip Failures as a fully matured DTC.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
Repair as necessary.
Perform the Shift Lever Position Test. If the test does not pass, refer to Symptom test
for P0705 Check Shifter Signal.
For Gear Ratio DTC's, check and record all CVI's.
Most DTC's set on start up but some must be set by driving the vehicle such that all
diagnostic monitors have run.
NOTE: Verify flash level of Transmission Control Module. Some problems
are corrected by software upgrades to the Transmission Control Module.
NOTE: Check for applicable TSB's related to the symptom.
Perform this procedure prior to Symptom diagnosis.All
Continue
Go To 2
11 0
TRANSMISSION
Page 4215 of 4284

TEST ACTION APPLICABILITY
2 With the DRBIIIt, check for other Transmission DTC's.
Is DTC P1791 present in addition to the DTC that you are diagnosing?All
Ye s®Refer to DTC list and perform symptom for P1791
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 3
3 With the DRBIIIt, read Transmission DTC's
Are there any Transmission Control Relay related DTC's P1765, 1767, or 1768
present?All
Ye s®Refer to symptom list and perform the appropriate test for
Transmission Relay related DTC's.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 4
4 With the DRBIIIt, Check the STARTS SINCE SET counter.
NOTE: This counter only applies to the last DTC set.
Is the STARTS SINCE SET counter 2 or less?All
Ye s®Go To 5
No®Go To 11
5 Turn the ignition off to the lock position.
CAUTION: Remove the Starter Relay from the PDC. This will prevent the
vehicle from being started in gear.
Install Transmission Simulator, Miller tool #8333 and the FWD Adapter Cable kit,
Miller tool #8333-1.
Note: Check connectors - Clean/repair as necessary.
Ignition on, engine not running.
On the Transmission Simulator select L/R on the Pressure Switch selector switch.
With the DRBIIIt, monitor the L/R Pressure Switch state while pressing the
Pressure Switch Test button on the Transmission Simulator.
Did the Pressure Switch state change from OPEN to CLOSED when the test button
was pressed?All
Ye s®Replace the Solenoid/Pressure Switch Assembly in accordance
with the Service Information.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 6
111
TRANSMISSION
P1784-LR PRESSURE SWITCH SENSE CIRCUIT ÐContinued
Page 4216 of 4284

TEST ACTION APPLICABILITY
6 Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Remove the Transmission Control Relay from the IPM.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between the Transmission Control Relay Output circuit and
the Fused B+ circuit in the IPM.
Using a 12-volt test light connected to ground, check the Transmission Control Relay
Output circuit in the Solenoid/Pressure Switch Assembly harness connector.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s®Go To 7
No®Repair the Transmission Control Relay Output circuit for an open
or high resistance. If the fuse is open make sure to check for a
short to ground.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
7 Turn the ignition off to the lock position.
Disconnect the TCM harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Note: Check connectors - Clean/repair as necessary.
Measure the resistance of the L/R Pressure Switch Sense circuit from the TCM
harness connector to the Transmission Solenoid/Pressure Switch Assembly harness
connector.
Is the resistance above 5.0 ohms?All
Ye s®Repair the L/R Pressure Switch Sense circuit for an open.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 8
8 Turn the ignition off to the lock position.
Disconnect the TCM harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Note: Check connectors - Clean/repair as necessary.
Measure the resistance between ground and the L/R Pressure Switch Sense circuit in
the Transmission Solenoid/Pressure Switch harness connector.
Is the resistance below 5.0 ohms?All
Ye s®Repair the L/R Pressure Switch circuit for a short to ground.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 9
11 2
TRANSMISSION
P1784-LR PRESSURE SWITCH SENSE CIRCUIT ÐContinued