Mercedes-Benz Sprinter / Dodge Sprinter. Manual — part 556

TEST

ACTION

APPLICABILITY

3

Turn the ignition off to the lock position.
Remove the TCM harness connector.
Disconnect the Solenoid harness connector.
Check the resistance between the Solenoid Supply circuit and all other circuits in the
TCM harness connector.
Is the resistance below 5.0 ohms between Solenoid Supply and any other circuit?

All

Yes

→ Repair the Solenoid Supply circuit short to other circuits.

Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.

No

→ The TCM has an internal error. Replace the Transmission Control

Module.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.

106

TRANSMISSION - NAG1

SOLENOID SUPPLY/WATCHDOG —

Continued

Symptom:

SYSTEM OVERVOLTAGE

When Monitored and Set Condition:

SYSTEM OVERVOLTAGE

When Monitored:

Always monitored with system active at each ignition cycle

Set Condition:

Ignition voltage above 16.9 volts with the engine and transmission input

speed sensors above 2000 rpm for 60 seconds

POSSIBLE CAUSES

VEHICLE JUMP STARTED IMPROPERLY

ENGINE CHARGING SYSTEM DTC’S PRESENT

TRANSMISSION RELAY OUTPUT HIGH AT TCM

TCM - SYSTEM OVERVOLTAGE

TEST

ACTION

APPLICABILITY

1

NOTE: 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 DRBIII

t, read the engine DTCs. Check and repair all engine DTCs prior to

performing transmission symptom diagnostics.
With the DRBIII

t, 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

Determine is the vehicle was jump started improperly.
NOTE: If the battery was jump started with the batteries in series, the
System Overvoltage DTC will be set.
Was the vehicle jump started improperly?

All

Yes

→ Erase the DTC , if the vehicle was jump started improperly.

Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.

No

→ Go To 3

107

TRANSMISSION - NAG1

TEST

ACTION

APPLICABILITY

3

With the DRBIII

t, read the Engine DTC’s.

Are there any Engine Charging System DTC’s present?

All

Yes

→ Refer to the Charging 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.
Disconnect the TCM C1 harness connector.
Check connectors - Clean/repair as necessary.
Start the engine.
Increase the Engine Speed to 1500 RPM.
Measure the voltage of the Transmission Relay Output circuit in the TCM C1
harness connector.
Is the voltage below 16.9 volts?

All

Yes

→ Go To 5

No

→ Refer the Charging category and perform the symptom, Charging

System with No DTCs present.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.

5

If there are no possible causes remaining, view repair.

All

Repair

Replace the TCM.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.

108

TRANSMISSION - NAG1

SYSTEM OVERVOLTAGE —

Continued

Symptom:

SYSTEM UNDERVOLTAGE

When Monitored and Set Condition:

SYSTEM UNDERVOLTAGE

When Monitored:

Always monitored with system active at each ignition cycle.

Set Condition:

Ignition voltage falls below 8.5 volts with the engine rpm greater than

2000 rpm for 60 seconds.

POSSIBLE CAUSES

ENGINE CHARGING SYSTEM DTC’S PRESENT

TRANSMISSION RELAY OUTPUT LO AT TCM

TCM - SYSTEM UNDER VOLTAGE

TEST

ACTION

APPLICABILITY

1

NOTE: 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 DRBIII

t, read the engine DTCs. Check and repair all engine DTCs prior to

performing transmission symptom diagnostics.
With the DRBIII

t, 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

With the DRBIII

t, read Engine DTC’s.

Are there any Engine Charging System DTC’s present?

All

Yes

→ Refer to the Charging category and perform the appropriate

symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.

No

→ Go To 3

109

TRANSMISSION - NAG1