
Symptom:
P1792-BATTERY WAS DISCONNECTED
When Monitored and Set Condition:
P1792-BATTERY WAS DISCONNECTED
When Monitored: Whenever the key is in the Run/Start position.
Set Condition: This code is set whenever Transmission Control Module (TCM) is
disconnected from battery power B+ or ground. It will also be set during the DRBIIIt
Quick Battery Disconnect procedure.
POSSIBLE CAUSES
QUICK LEARN WAS PERFORMED
RECENT BATTERY DISCONNECTION
TCM WAS REPLACED OR DISCONNECTED
INTERMITTENT WIRING AND CONNECTORS
FUSED B+ CIRCUIT TO TCM OPEN
GROUND CIRCUIT OPEN
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
127
TRANSMISSION

TEST ACTION APPLICABILITY
2 Turn ignition off to the lock position.
Disconnect the TCM harness connector.
Ignition on, engine not running.
Measure the voltage of the Fused B+ circuit in the TCM harness connector.
Is the voltage below 10.0 volts?All
Ye s®Go To 3
No®Go To 5
3 Turn the ignition off to the lock position.
Disconnect the TCM harness connector.
Note: Check connectors - Clean/repair as necessary.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, check the Fused B+ circuit in the TCM
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 4
No®Repair the Fused B+ circuit for a 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.
4 Turn ignition off to the lock position.
Disconnect the TCM harness connector.
Note: Check connectors - Clean/repair as necessary.
Using a 12-volt test light connected to 12-volts, check all the ground circuits in the
TCM harness connector.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the light illuminate brightly at all ground circuits?All
Ye s®Test Complete.
No®Repair the Ground circuit(s) as necessary.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
5 Has the Quick Learn procedure been performed? All
Ye s®This is the cause of the DTC. Erase the DTC and return vehicle to
customer.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 6
6 Has the battery been disconnected, lost it's charge, or been replaced recently? All
Ye s®This is the cause of the DTC. Erase the DTC and return vehicle to
customer.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 7
7 Has the TCM been replaced or disconnected? All
Ye s®Replacing or disconnecting the TCM will set this DTC. Erase the
DTC and return the vehicle to the customer.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Go To 8
128
TRANSMISSION
P1792-BATTERY WAS DISCONNECTED ÐContinued

TEST ACTION APPLICABILITY
8 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.
129
TRANSMISSION
P1792-BATTERY WAS DISCONNECTED ÐContinued

Symptom:
P1793-TRD LINK COMMUNICATION ERROR
When Monitored and Set Condition:
P1793-TRD LINK COMMUNICATION ERROR
When Monitored: The transmission controller pulses the 12 volt TRD signal from the
PCM to ground, during torque managed shifts with the throttle angle above 54 degrees.
The TRD system is also tested whenever the vehicle is stopped and the engine speed is at
idle.
Set Condition: This code is set when the Transmission Control Module (TCM) sends two
subsequent torque reduction messages to the Powertrain Control Module (PCM) via the
TRD link circuit and does not receive a confirmation from the PCM over the communica-
tion bus.
POSSIBLE CAUSES
RELATED DTC'S PRESENT
INTERMITTENT WIRING AND CONNECTORS
TORQUE MANAGEMENT REQUEST SENSE CIRCUIT OPEN
TORQUE MANAGEMENT REQUEST SENSE SHORT TO GROUND
TORQUE MANAGEMENT REQUEST SENSE CIRCUIT SHORT TO VOLTAGE
PCM - TRD LINK
TCM - TRD LINK
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
130
TRANSMISSION

Symptom:
P1794-SPEED SENSOR GROUND ERROR
When Monitored and Set Condition:
P1794-SPEED SENSOR GROUND ERROR
When Monitored: The transmission gear ratio is monitored continuously while the
transmission is in gear.
Set Condition: After a TCM reset in neutral and Input/Output equals a ratio of input to
output of 2.50
POSSIBLE CAUSES
INTERMITTENT WIRING AND CONNECTORS
SPEED SENSOR GROUND CIRCUIT OPEN
TCM - SPEED SENSOR GROUND
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 Start the engine in park.
With the DRBIIIt, observe the Input and Output Speed Sensor readings.
Is the Output Speed Sensor reading twice the Input Speed Sensor reading?All
Ye s®Go To 4
No®Go To 3
133
TRANSMISSION

Symptom:
P1797-MANUAL SHIFT OVERHEAT
When Monitored and Set Condition:
P1797-MANUAL SHIFT OVERHEAT
When Monitored: Whenever engine is running and transmission is in the AutoStick
mode.
Set Condition: If the engine temperature exceeds 255 deg. F or the transmission
temperature exceeds 275 deg. F while in AutoStick mode. note: Aggressive driving or
driving in low for extended periods of time in AutoStick mode will set this code.
POSSIBLE CAUSES
MANUAL SHIFT OVERHEAT
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 This is an informational DTC only.
Check the Engine and Transmission Cooling Systems for proper operation.
Check the Radiator Cooling Fan operation.
Check the Transmission Cooling Fan operation if equipped.
Check the Transmission Fluid Level. Make sure it is not overfilled.
NOTE: Aggressive driving or driving in low for extended periods of time in
Autosticktmode will set this DTC.
Were there any problems found?All
Ye s®Repair as necessary.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Test Complete.
139
TRANSMISSION

Symptom:
P1798-WORN OUT/BURNT TRANSAXLE FLUID
When Monitored and Set Condition:
P1798-WORN OUT/BURNT TRANSAXLE FLUID
When Monitored: With each transition from full Torque Convertor to partial Torque
Convertor engagement for A/C bump prevention.
Set Condition: When vehicle shudder is detected during partial engagement (PEMCC).
POSSIBLE CAUSES
WORN OUT/ BURNT TRANSMISSION FLUID
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
140
TRANSMISSION

TEST ACTION APPLICABILITY
2 Turn the ignition off.
Remove the Transmission Oil Pan and Oil Filter per the Service Information.
Install a new Transmission Oil Filter per Service Information.
Reinstall Transmission Oil Pan, and refill with new Transmission Fluid per the
Service Information.
Note: The Transmission Cooler must be flushed before prodceeding.
Start the engine, check and adjust the Transmission Fluid Level per Service
Information.
Allow the engine to idle for 10 minutes, in Park.
Flush the Transmission Oil Cooler per the Service Information.
Turn the ignition off.
Drain and refill the Transmission Fluid.
Flush the Transmission Oil Cooler again.
Start the engine, check and adjust the Transmission Fluid Level per Service
Information.
With the DRBIIIt, perform a Battery Disconnect.
Note: This must be done to re enable EMCC during an A/C Clutch engage-
ment.
The vehicle may exhibit intermittent shudder during the first few hundred miles.
Note: The oil will gradually penetrate the TCC friction material and the
shudder should disappear.
Erase the DTC and return the vehicle to the customer.
Did the Code reset or does the vehicle still shudder after a few thousand miles?All
Ye s®Replace the Torque Convertor per the Service Information. Note:
After replacing the Torque Convertor, use the DRBIII to perform
the TCC Break In procedure. This will prevent possible shudder
conditions.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
No®Test Complete.
141
TRANSMISSION
P1798-WORN OUT/BURNT TRANSAXLE FLUID ÐContinued