Page 4161 of 4284

Symptom:
P0734-GEAR RATIO ERROR IN 4TH
When Monitored and Set Condition:
P0734-GEAR RATIO ERROR IN 4TH
When Monitored: The Transmission Gear Ratio is monitored continuously while the
Transmission is in Gear.
Set Condition: If the ratio of the input RPM to the output RPM does not match the
current Gear Ratio.
POSSIBLE CAUSES
RELATED DTC'S PRESENT
RELATED PRESSURE SWITCH DTC'S PRESENT
INTERMITTENT GEAR RATIO ERRORS
TRANSMISSION - INTERNAL
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
57
TRANSMISSION
Page 4162 of 4284

TEST ACTION APPLICABILITY
2 With the DRBIIIt, read Transmission Control Module DTC's
If any of these DTC's are present, perform their respective tests first.
Are DTC's P1791, P0715, P0720, P1794, P1720, present also?All
Ye s®Refer to appropriate symptom in the Transmission category. If
any of these DTC's are present, they will cause a gear ratio error.
Go to test P1791 first if it is present.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 3
3NOTE: Low fluid level can be the cause of many transmission problems.
Check and adjust the fluid level per the Service Information. If the fluid
level is low, locate and repair the leak before returning the vehicle to the
customer.
With the DRBIIIt, perform the 4th gear clutch test. Follow the instructions on the
DRBIIIt.
Increase the throttle angle, TPS Degree, to 30É for no more than a few seconds.
CAUTION: Do not overheat the transmission.
Did the clutch test pass, Input Speed remain at 0?All
Ye s®Go To 4
No®Go To 5
4 The conditions to set this DTC are not present at this time.
Check the gearshift linkage adjustment.
Gear Ratio DTC's can be set by problems in the Input and Output Speed Sensor
circuits. If the vehicle passes the clutch test and still sets Gear Ratio DTC(s), check
the Speed Sensors for proper operation.
NOTE: Remove the Starter Relay from the PDC. This will prevent the
vehicle from being started in gear.
Check the Speed Sensor wiring and connectors for good connection, then perform a
wiggle test using the Transmission Simulator, Miller tool #8333 and the FWD
Adapter Cable kit, Miller tool #8333-1.
This DTC can also be set under extreme temperature conditions, this is usually
caused by an internal problem. Verify if the problem is only experienced under
extreme hot or cold conditions.
Were there any problems found?All
Ye s®Repair as necessary.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Test Complete.
5 With the DRBIIIt, read Transmission DTC's.
Is a DTC P1788 - 2/4 Hydraulic Pressure Switch and/or P1782 - 2/4 Pressure Switch
present also?All
Ye s®Replace the Solenoid/Pressure switch assembly.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 6
6 If there are no possible causes remaining, view repair. All
Repair
Repair internal transmission problem. If the transmission is to be
repaired, check all of the components related to the Overdrive and
2/4 clutches. Inspect the pump per service information and repair
as necessary.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
58
TRANSMISSION
P0734-GEAR RATIO ERROR IN 4TH ÐContinued
Page 4163 of 4284

Symptom:
P0736-GEAR RATIO ERROR IN REVERSE
When Monitored and Set Condition:
P0736-GEAR RATIO ERROR IN REVERSE
When Monitored: The Transmission Gear Ratio is monitored continuously while the
Transmission is in Gear.
Set Condition: If the ratio of the input RPM to the output RPM does not match the
current Gear Ratio.
POSSIBLE CAUSES
RELATED DTC'S PRESENT
INTERMITTENT GEAR RATIO ERRORS
TRANSMISSION - INTERNAL
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
2 With the DRBIIIt, read Transmission DTC's
If any of these DTC's are present, perform their respective tests first.
Are DTC's P1791, P0715, P0720, P1794, P1720, present also?All
Ye s®Refer to appropriate symptom in the Transmission category. If
any of these DTC's are present, they will cause a gear ratio error.
Go to test for P1791 first if it is present.
No®Go To 3
59
TRANSMISSION
Page 4164 of 4284

TEST ACTION APPLICABILITY
3NOTE: Low fluid level can be the cause of many transmission problems.
Check and adjust the fluid level per the Service Information. If the fluid
level is low, locate and repair the leak before returning the vehicle to the
customer.
With the DRBIIIt, perform the Reverse gear clutch test. Follow the instructions on
the DRBIIIt.
Increase the throttle angle, TPS Degree, to 30É for no more than a few seconds.
CAUTION: Do not overheat the Transmission.
Did the clutch test pass, Input Speed remain at 0?All
Ye s®Go To 4
No®Go To 5
4 The conditions to set this DTC are not present at this time.
Check the gearshift linkage adjustment.
Gear Ratio DTC's can be set by problems in the Input and Output Speed Sensor
circuits. If the vehicle passes the clutch test and still sets Gear Ratio DTC(s), check
the Speed Sensors for proper operation.
NOTE: Remove the starter relay before installing the Transmission Simu-
lator.
Check the speed sensor wiring and connectors for good connection, then perform a
wiggle test using the Transmission Simulator, Miller tool #8333 and the FWD
Adapter Cable kit, Miller tool #8333-1.
This DTC can also be set under extreme temperature conditions, this is usually
caused by an internal problem. Ask the customer if the problem is only experienced
under extreme hot or cold conditions.
Were there any problems found?All
Ye s®Repair as necessary.
No®Test Complete.
5 If there are no possible causes remaining, view repair. All
Repair
Repair internal transmission problem. If the transmission is to be
repaired, check all of the components related to the Reverse and
L/R clutches. Inspect the pump per service information and repair
as necessary.
60
TRANSMISSION
P0736-GEAR RATIO ERROR IN REVERSE ÐContinued
Page 4165 of 4284

Symptom:
P0740-TORQUE CONVERTER CLUTCH CONTROL CIRCUIT
When Monitored and Set Condition:
P0740-TORQUE CONVERTER CLUTCH CONTROL CIRCUIT
When Monitored: During Electronically Modulated Converter Clutch (EMCC) Operation.
Set Condition: A) Transmission must be in EMCC, with input speed > than 1750 RPM.
TCC/L-R sol achieves the maximum duty cycle & can't pull engine RPM within 60 RPM of
input speed. B) Transmissions is in FEMCC & engine slips TCC > than 100 RPM for 10
seconds.
POSSIBLE CAUSES
RELATED DTC'S PRESENT
INTERMITTENT OPERATION
INCORRECT FLUID LEVEL
INTERNAL TRANSMISSION PROBLEM - TCC OUT OF RANGE
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
61
TRANSMISSION
Page 4166 of 4284

TEST ACTION APPLICABILITY
2 Ignition on, engine not running.
With the DRBIIIt, read Transmission DTC's
Are the DTCs P0750 and/or P1784 present also?All
Ye s®Refer to symptom list for problems related to DTC P0750 and/or
P1784.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 3
3 Ignition on, engine not running.
With the DRBIIIt, record and erase Transmission DTCs.
Drive the vehicle until it is fully warmed up to at least 43.33É C or 110É F.
Perform the following steps 3 times.
With the DRBIIIt, monitor TPS degree.
Drive the vehicle to the speed of 83.45 Km/h or 50 MPH and allow 4th gear to engage
for at least 10 seconds.
Close the throttle, then tip back in until the throttle angle, TPS degrees, is between
25 and 29 degrees.
NOTE: If you go over 30 TPS degrees, you must back off of the throttle and
retry.
Did the TCC engage during any of the attempts?All
Ye s®Go To 4
No®Go To 5
4 The conditions necessary to set the DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this
circuit.
Wiggle the wires while checking for shorts and open circuits.
This DTC can also be set under extreme temperature conditions, this is usually
caused by an internal problem. Verify if the problem is only experienced under
extreme hot or cold conditions.
Were there any problems found?All
Ye s®Repair as necessary.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Test Complete.
5 Check the Transmission Fluid level per the Service Information.
Is the Transmission Fluid level at the proper level?All
Ye s®Go To 6
No®Adjust the Transmission fluid level per the Service Information.
Repair the cause of the incorrect Transmission Fluid level.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
6 If there are no possible causes remaining, view repair. All
Repair
Repair internal transmission problem. Inspect the Valve Body per
service information and replace if necessary. If no problems are
found in the Valve Body, replace the Solenoid/Pressure switch
assembly. Replace the Torque Converter in either case
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
62
TRANSMISSION
P0740-TORQUE CONVERTER CLUTCH CONTROL CIRCUIT ÐContinued
Page 4167 of 4284

Symptom:
P0750-LR SOLENOID CIRCUIT
When Monitored and Set Condition:
P0750-LR SOLENOID CIRCUIT
When Monitored: Initially at power-up, then every 10 seconds thereafter. The solenoids
will also be tested immediately after a Gear Ratio or Pressure Switch error is detected.
Set Condition: Three consecutive solenoid continuity test failures, or one failure if a test
is run in response to a Gear Ratio or Pressure Switch error.
POSSIBLE CAUSES
RELATED RELAY DTC'S PRESENT
INTERMITTENT WIRING AND CONNECTORS
TRANSMISSION CONTROL RELAY OUTPUT CIRCUIT OPEN
L/R SOLENOID CONTROL CIRCUIT OPEN
L/R SOLENOID CONTROL CIRCUIT SHORT TO GROUND
L/R SOLENOID CONTROL CIRCUIT SHORT TO VOLTAGE
L/R SOLENOID INOPERATIVE
TCM - L/R SOLENOID
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
63
TRANSMISSION
Page 4168 of 4284

TEST ACTION APPLICABILITY
2 Ignition on, engine not running.
With the DRBIIIt, read Transmission Control Module DTC's
Are there any Transmission Control Relay related DTC's P1765, P1767, or P1768
present?All
Ye s®Refer to symptom list and perform the appropriate symptom 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 for P0750 set at 0?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.
Ignition on, engine not running.
With the DRBIIIt, actuate the L/R Solenoid.
Monitor the L/R Solenoid LED on the Transmission Simulator #8333.
Did the L/R Solenoid LED on the Transmission Simulator blink on and off during
actuation?All
Ye s®Go To 5
No®Go To 6
5 If there are no possible causes remaining, view repair. All
Repair
Replace the Transmission Solenoid/Pressure switch assembly .
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
6 Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid/Pressure Switch 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.
64
TRANSMISSION
P0750-LR SOLENOID CIRCUIT ÐContinued