Page 2203 of 2305

Symptom:
ABS LF SENSOR MESSAGE
When Monitored and Set Condition:
ABS LF SENSOR MESSAGE
When Monitored: Valid ABS CAN messages received at least once and the CAN Bus
circuit, ABS CAN Message Missing, ABS CAN Message Incorrect are not active
Set Condition: ABS signal9Wheel Speed Front Left9not valid or ABS has detected a
sensor failure.
POSSIBLE CAUSES
CAN BUS CIRCUIT DTC PRESENT
ABS DTCS PRESENT
ABS CONTROL MODULE - ABS LF SENSOR MESSAGE
TCM - ABS LF SENSOR MESSAGE
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 DTCs. Check and repair all engine DTCs prior to
performing transmission symptom diagnostics.
With the DRBIIIt, read and record all Transmission DTCs.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal
connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
Repair as necessary.
Most DTCs 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 controller. Some problems are
corrected by software upgrades to the transmission controller.
NOTE: Check for any Technical Service Bulletins that may apply.
Perform this procedure prior to Symptom diagnosis.All
Continue
Go To 2
2 Ignition on, engine not running.
With the DRBIIIt, read Transmission DTCs.
NOTE: If the DTC, CAN BUS CIRCUIT, is present, perform diagnostics on
that symptom first.
Is the DTC, CAN BUS CIRCUIT, present?All
Ye s!Refer to the Transmission category and perform the appropriate
symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 3
38
TRANSMISSION - NAG1
Page 2204 of 2305
TEST ACTION APPLICABILITY
3 Ignition on, engine not running.
With the DRBIIIt, read ABS DTCs.
Are there any ABS DTCs present?All
Ye s!Refer to the BRAKE category and perform the appropriate
symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 4
4 Turn the ignition off to the lock position.
Replace the ABS Control Module per the Service Information.
With the DRBIIIt, erase Transmission DTCs.
Road test the Vehicle.
With the DRBIIIt, read Transmission DTCs.
Does the DTC, ABS LF SENSOR MESSAGE, reset?All
Ye s!Replace the Transmission Control Module.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Test complete.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
39
TRANSMISSION - NAG1
ABS LF SENSOR MESSAGE ÐContinued
Page 2205 of 2305

Symptom:
ABS LR SENSOR MESSAGE
When Monitored and Set Condition:
ABS LR SENSOR MESSAGE
When Monitored: Valid ABS CAN messages received at least once and the CAN Bus
circuit, ABS CAN Message Missing, ABS CAN Message Incorrect are not active
Set Condition: ABS signal9wheel speed rear left9not valid or ABS has detected a sensor
failure.
POSSIBLE CAUSES
CAN BUS CIRCUIT DTC PRESENT
ABS DTCS PRESENT
ABS CONTROL MODULE - ABS LR SENSOR MESSAGE
TCM - ABS LR SENSOR MESSAGE
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 DTCs. Check and repair all engine DTCs prior to
performing transmission symptom diagnostics.
With the DRBIIIt, read and record all Transmission DTCs.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal
connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
Repair as necessary.
Most DTCs 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 controller. Some problems are
corrected by software upgrades to the transmission controller.
NOTE: Check for any Technical Service Bulletins that may apply.
Perform this procedure prior to Symptom diagnosis.All
Continue
Go To 2
2 Ignition on, engine not running.
With the DRBIIIt, read Transmission DTCs.
NOTE: If the DTC, CAN BUS CIRCUIT, is present, perform diagnostics on
that symptom first.
Is the DTC, CAN BUS CIRCUIT, present?All
Ye s!Refer to the Transmission category and perform the appropriate
symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 3
40
TRANSMISSION - NAG1
Page 2206 of 2305
TEST ACTION APPLICABILITY
3 Ignition on, engine not running.
With the DRBIIIt, read ABS DTCs.
Are there any ABS DTCs present?All
Ye s!Refer to the BRAKE category and perform the appropriate
symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 4
4 Turn the ignition off to the lock position.
Replace the ABS Control Module per the Service Information.
With the DRBIIIt, erase Transmission DTCs.
Road test the Vehicle.
With the DRBIIIt, read Transmission DTCs.
Does the DTC, ABS LR SENSOR MESSAGE, reset?All
Ye s!Replace the Transmission Control Module.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Test complete.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
41
TRANSMISSION - NAG1
ABS LR SENSOR MESSAGE ÐContinued
Page 2207 of 2305

Symptom:
ABS RF SENSOR MESSAGE
When Monitored and Set Condition:
ABS RF SENSOR MESSAGE
When Monitored: Valid ABS CAN messages received at least once and the CAN Bus
circuit, ABS CAN Message Missing, ABS CAN Message Incorrect are not active
Set Condition: ABS signal9Wheel Speed Front Right9not valid or ABS has detected a
sensor failure.
POSSIBLE CAUSES
CAN BUS CIRCUIT DTC PRESENT
ABS DTCS PRESENT
ABS CONTROL MODULE - ABS RF SENSOR MESSAGE
TCM - ABS RF SENSOR MESSAGE
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 DTCs. Check and repair all engine DTCs prior to
performing transmission symptom diagnostics.
With the DRBIIIt, read and record all Transmission DTCs.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal
connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
Repair as necessary.
Most DTCs 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 controller. Some problems are
corrected by software upgrades to the transmission controller.
NOTE: Check for any Technical Service Bulletins that may apply.
Perform this procedure prior to Symptom diagnosis.All
Continue
Go To 2
2 Ignition on, engine not running.
With the DRBIIIt, read Transmission DTCs.
NOTE: If the DTC, CAN BUS CIRCUIT, is present, perform diagnostics on
that symptom first.
Is the DTC, CAN BUS CIRCUIT, present?All
Ye s!Refer to the Transmission category and perform the appropriate
symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 3
42
TRANSMISSION - NAG1
Page 2208 of 2305
TEST ACTION APPLICABILITY
3 Ignition on, engine not running.
With the DRBIIIt, read ABS DTCs.
Are there any ABS DTCs present?All
Ye s!Refer to the BRAKE category and perform the appropriate
symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 4
4 Turn the ignition off to the lock position.
Replace the ABS Control Module per the Service Information.
With the DRBIIIt, erase Transmission DTCs.
Road test the Vehicle.
With the DRBIIIt, read Transmission DTCs.
Does the DTC, ABS RF SENSOR MESSAGE, reset?All
Ye s!Replace the Transmission Control Module.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Test complete.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
43
TRANSMISSION - NAG1
ABS RF SENSOR MESSAGE ÐContinued
Page 2209 of 2305

Symptom:
ABS RR SENSOR MESSAGE
When Monitored and Set Condition:
ABS RR SENSOR MESSAGE
When Monitored: Valid ABS CAN messages received at least once and the CAN Bus
circuit, ABS CAN Message Missing, ABS CAN Message Incorrect are not active
Set Condition: ABS signal9wheel speed rear right9not valid or ABS has detected a sensor
failure.
POSSIBLE CAUSES
CAN BUS CIRCUIT DTC PRESENT
ABS DTCS PRESENT
ABS CONTROL MODULE - ABS RR SENSOR MESSAGE
TCM - ABS RR SENSOR MESSAGE
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 DTCs. Check and repair all engine DTCs prior to
performing transmission symptom diagnostics.
With the DRBIIIt, read and record all Transmission DTCs.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal
connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
Repair as necessary.
Most DTCs 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 controller. Some problems are
corrected by software upgrades to the transmission controller.
NOTE: Check for any Technical Service Bulletins that may apply.
Perform this procedure prior to Symptom diagnosis.All
Continue
Go To 2
2 Ignition on, engine not running.
With the DRBIIIt, read Transmission DTCs.
NOTE: If the DTC, CAN BUS CIRCUIT, is present, perform diagnostics on
that symptom first.
Is the DTC, CAN BUS CIRCUIT, present?All
Ye s!Refer to the Transmission category and perform the appropriate
symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 3
44
TRANSMISSION - NAG1
Page 2210 of 2305
TEST ACTION APPLICABILITY
3 Ignition on, engine not running.
With the DRBIIIt, read ABS DTCs.
Are there any ABS DTCs present?All
Ye s!Refer to the BRAKE category and perform the appropriate
symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 4
4 Turn the ignition off to the lock position.
Replace the ABS Control Module per the Service Information.
With the DRBIIIt, erase Transmission DTCs.
Road test the Vehicle.
With the DRBIIIt, read Transmission DTCs.
Does the DTC, ABS RR SENSOR MESSAGE, reset?All
Ye s!Replace the Transmission Control Module.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Test complete.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
45
TRANSMISSION - NAG1
ABS RR SENSOR MESSAGE ÐContinued