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Dodge Nitro. Manual - part 335

REVERSE GEAR

POSITION BLOCKED

ENGAGEMENT WHEN

MOVING SHIFT LEVER

FROM D POSITION

1. Customer shifting into R at vehicle
speeds greater than 7 mph.

position is blocked at vehicle
speeds greater than 7 mph.

2. Shift system malfunction.

2. Inspect shift system for proper
adjustment or damage. Check
shifter for DTCs. Repair as
needed.

NO ENGINE CRANKING

IN P OR N

1. Gearshift cable adjustment.

1. Adjust shift cable and retest.

2. Shift system malfunction.

2. Check shifter DTCs. Inspect
shift cable and lever assembly.
Adjust and/or replace
worn/damaged parts.

3. Valve body malfunction.

3. Starter lockout contact
malfunction. Remove valve body,
replace lead frame assembly. See
OPERATION.

INCORRECT

TRANSMISSION

TEMPERATURE

1. Defective Trans Temp Sensor.

Verify proper temperature sensor
operation.

SPEED SENSOR ERROR

1. Loose/Corroded TCM Connector
(Both C1 and C2 Connectors).

1. Disconnect, inspect, and
reconnect TCM connector. Make
sure to check for any pushed out
pins.

2. Unlatched Electrohydraulic Unit
connector.

2. Remove the Electrohydraulic
Unit connector and inspect for
any oil or damaged pins. (Note:
There is no Electrohydraulic Unit
connector pin in position #5) Re-
attach the connector and insure
that the locking ring tab is fully
latched.

3. Wires Shorted or Open.

3. Ohm the speed sensor wires to
make sure there is not a short to
another circuit or ground.
Visually inspect for any chafing
of the wires. Repair as necessary.

4. TCM Defective.

4. After checking the wiring and
connectors replace the TCM.

1. Leak in area of bell housing.

1. Check bolt torque on internal
bell housing bolts. If loose,
replace fastener and torque to
proper level. If bolts are to proper
torque level, check pump outer
seal and impeller seal. Replace if
needed.

2. Leak in area of control unit (valve

2. Check connector for damaged
(cut), flattened or missing o-rings.

2007 Dodge Nitro R/T

2007 AUTOMATIC TRANSMISSION NAG1 - Service Information - Nitro

GENERAL CONDITIONS

Transmission malfunctions may be caused by these general conditions:

Poor engine performance.

Improper adjustments.

Hydraulic malfunctions.

FLUID LEAK

body) electrical connector.

Replace as needed.

3. Leak in area of pan gasket.

3. Check for proper torque on oil
pan clamps. Check for mis-
positioned or rolled gasket.
Repair as needed.

4. Leak in area of park guide plug.

4. Remove park guide plug.
Check for damaged (cut) or
missing o-ring. If o-ring is in
good condition, install new plug.

5. Leak in area of shift lever.

5. Check for damaged shift lever
seal or damaged lever. Repair as
needed.

6. Leak in area of output flange.

6. Check for worn/damaged
slinger seal and output seal.
Visually inspect output flange
seal surface for damage. Repair as
needed.

7. Leak in area of transmission vent.

7. Check fluid level for overfill
condition. Adjust as needed. If
fluid level is within specification,
ride check vehicle. Monitor
transmission temperature. If high
operating temperatures are
observed, fluid may be
contaminated or cooling system
malfunctioning. Change fluid per
service information procedures.
Refer to cooling system
diagnostics if needed.

8. Leak in area of transmission fill tube.

8. Inspect fill tube cap for proper
installation. Inspect fill tube
grommet between case and fill
tube for leakage. Repair as
needed.

CAUTION: Before attempting any repair on a NAG1 automatic transmission, check for

Diagnostic Trouble Codes with the appropriate scan tool.

2007 Dodge Nitro R/T

2007 AUTOMATIC TRANSMISSION NAG1 - Service Information - Nitro

Mechanical malfunctions.

Electronic malfunctions.

Transfer case performance (if equipped).

Diagnosis of these problems should always begin by checking the easily accessible variables: fluid level and
condition, gearshift cable adjustment. Then perform a road test to determine if the problem has been corrected
or if more diagnosis is necessary.

PRELIMINARY - NAG1

Two basic procedures are required. One procedure for vehicles that are drivable and an alternate procedure for
disabled vehicles (will not back up or move forward).

VEHICLE IS DRIVABLE

1. Check for transmission fault codes using the appropriate scan tool.

2. Adjust gearshift cable if complaint was based on delayed, erratic, or harsh shifts.

3. Road test and note how transmission upshifts, downshifts, and engages.

4. Check fluid level and condition.

VEHICLE IS DISABLED

1. Check for broken or disconnected gearshift cable.

2. Check for cracked, leaking cooler lines, or loose or missing pressure-port plugs.

3. Check fluid level and condition.

4. Check shifter linkage: Is cable connected to lever at transmission and does the lever move with gear

change on the console shifter? If no movement, repair shift cable and or shifter.

5. With shifter in Park, attempt to rotate drive shaft(s) to ensure transmission output shaft coupler/flange is

secure.

6. Check the transfer case operation (if equipped).

7. Raise and support vehicle on safety stands, start engine with transmission in Park position and allow to

idle for several minutes, shift transmission into gear, and note following:



If propeller shaft turns but wheels do not, problem is with differential or axle shafts.



If propeller shaft does not turn and transmission is noisy, stop engine. Remove oil pan, and check
for debris. If pan is clear, remove transmission and check for damaged driveplate, converter, oil
pump, or input shaft.



If propeller shaft does not turn and transmission is not noisy, perform hydraulic-pressure test to
determine if problem is hydraulic or mechanical.

8. Air pressure test the B1, K3, and B2 clutch circuits. See DIAGNOSIS AND TESTING.

9. Check the TCM, Wiring, Valve body, and Solenoids (Utilize fault codes to diagnose if available).

10. Remove oil pan and check filter presence and condition (not plugged and seated).

11. If debris is found in the pan, tear down transmission and inspect all hard parts, Front Annulus Gear and

2007 Dodge Nitro R/T

2007 AUTOMATIC TRANSMISSION NAG1 - Service Information - Nitro

Gear to Retainer and Input Shaft (Shaft to Retainer) etc. , and clutches. If the hard parts did not show
signs of damage replace the torque converter and filter.

12. Remove valve body, disassemble, and inspect Line Pressure Regulating valve for being stuck, clean and

remove debris.

13. Check pump rotor for failed inner lugs that are driven by the T/C hub.

ROAD TESTING - NAG1

Before road testing, be sure the fluid level and control cable adjustments have been checked and adjusted if
necessary. Verify that all diagnostic trouble codes have been resolved.

Observe engine performance during the road test. A poorly tuned engine will not allow accurate analysis of
transmission operation.

Operate the transmission in all gear ranges. Check for shift variations and engine flare which indicates slippage.
Note if shifts are harsh, spongy, delayed, early, or if part throttle downshifts are sensitive.

Slippage indicated by engine flare, usually means clutch, overrunning clutch, or line pressure problems.

A slipping clutch can often be determined by comparing which internal units are applied in the various gear
ranges. The Clutch Application chart provides a basis for analyzing road test results.

AIR CHECKING TRANSMISSION CLUTCH OPERATION

CLUTCH APPLICATION

GEAR

RATIO

3.59

2.19

1.41

1.00

0.83

N/A

3.16

R - Limp

In or

4WD

Low

Range

1.93

* = The shift components required during coast.

2007 Dodge Nitro R/T

2007 AUTOMATIC TRANSMISSION NAG1 - Service Information - Nitro

Content .. 333 334 335 336 ..