Chrysler 300/300 Touring/300C, Dodge Magnum. Manual — part 1996

CONTROL MODULES/POWERTRAIN CONTROL MOD-
ULE - REMOVAL)

Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)

9.

INTERMITTENT WIRING AND CONNECTORS

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 wiring and connectors while checking for shorted and open circuits.

With the scan tool , check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set.

Were there any problems found?

Yes

>> Repair as necessary.

Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)

No

>> Test Complete.

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P0725-ENGINE SPEED SENSOR CIRCUIT

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Whenever the engine is running.

•

Set Condition:
The Engine RPM is less than 390 or greater than 8000 for more than 2 seconds while the engine is running.

Possible Causes

ENGINE DTCS PRESENT

POWERTRAIN CONTROL MODULE

Always perform the 42RLE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)

Theory of Operation

The PCM uses a dual port RAM internal to the controller to send the engine speed signal to the Transmission
Control System. The calculated engine RPM is compared to a minimum and maximum value. If the PCM interprets
this signal to be out of range when the engine is running the code is set. The MIL illuminates after 10 seconds of
vehicle operation and the transmission system defaults to Limp-in mode.

Diagnostic Test

1.

CONDITION FOR DTC P0725 IS PRESENT

Start the engine.

NOTE: This DTC is not a Transmission Input Speed Sensor DTC.
With the scan tool, view DTCs.

Is the status Active for this DTC or is the STARTS SINCE SET counter set at 0?

Yes

>> Go To 2

No

>> Go To 3

2.

ENGINE DTCS PRESENT

With the scan tool, read Engine DTCs.

Are there any Engine DTC’s present?

Yes

>> Refer to Section 9 – Engine Electrical Diagnostics and perform the appropriate diagnostic procedure.

Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)

No

>> Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion,

damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems
are found, replace the PCM per the Service Information. With the scan tool PERFORM QUICK LEARN,
then program Pinion Factor in the Front Control Module. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/POWERTRAIN CONTROL MODULE - REMOVAL)

Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)

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AUTOMATIC TRANSMISSION 42RLE - ELECTRICAL DIAGNOSTICS

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3.

INTERMITTENT WIRING AND CONNECTORS

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 wiring and connectors while checking for shorted and open circuits.

With the scan tool, check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set.

Were there any problems found?

Yes

>> Repair as necessary.

Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)

No

>> Test Complete.

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P0731-GEAR RATIO ERROR IN 1ST

For a complete wiring diagram Refer to Section 8W.

•

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 when compared to the
known gear ratio.

Possible Causes

RELATED TRANSMISSION DTCS PRESENT

INTERMITTENT GEAR RATIO ERRORS

INTERNAL TRANSMISSION

Always perform the 42RLE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)

Theory of Operation

The transmission system uses two speed sensors, one to measure input RPM and one to measure output RPM.
These inputs are essential for proper transmission operation. Therefore, the integrity of this data is verified through
data checks. When in gear, if the gear ratio does not compare to a known gear ratio, the corresponding gear ratio
error trouble code is set. The transmission will go into Limp-in mode after four gear ratio error events occur in a
given driving cycle.

Diagnostic Test

1.

DETERMINING IF RELATED TRANSMISSION DTCS ARE PRESENT

With the scan tool, read Transmission DTCs.

If any of these DTCs are present, perform their respective tests first.

Are there any Loss of Prime, Line Pressure Sensor and/or Speed Sensor DTCs present?

Yes

>> Refer to appropriate diagnostic procedure in the Transmission category. If any of these DTC’s are

present, they will cause a gear ratio error. Perform the test for Loss of Prime first if it is present.

No

>> Go To 2

2.

CHECK TO SEE IF P0731 IS CURRENT

With the scan tool, perform the 1st gear clutch test. Follow the instructions on the scan tool.

Increase the throttle angle or TPS Degree to 30° for no more than a few seconds.

CAUTION: Do not overheat the transmission.

Did the Clutch Test pass, Input Speed remain at zero?

Yes

>> Go To 3

No

>> Go To 4

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