The Transmission Control Module (TCM) monitors the engine speed over the CAN bus. If the engine speed is
greater than 4100+ 800 RPM, the TCM assumes that either the information from the Powertrain Control Module
(PCM) is incorrect or that a major mechanical problem exist. Once the DTC is set, the TCM will position the trans-
mission gear into neutral to protect the engine and transmissin from damage. The transmission will remain in neutral
and will not be revaluated by the TCM until the ignition is cycled.

•

When Monitored:
Continuously with the ignition on, engine running, with the transmission in gear with a valid Engine RPM mes-
sage received at least once, and the CAN Bus Circuit and Engine CAN Message Missing are not active.

•

Set Condition:
Engine speed is greater than 5700 RPM + 500 RPM.

Possible Causes

MECHANICAL ENGINE PROBLEM

MECHANICAL TRANSMISSION PROBLEM

POWERTRAIN CONTROL MODULE

TRANSMISSION CONTROL MODULE

Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

Diagnostic Test

CHECK FOR OTHER TRANSMISSION DTCS

With the scan tool, check for other transmission DTCs.

Are there any gear ratio and/or speed sensor DTCs present in addition to P0219?

Yes

>> Refer to the Symptom Category and perform the appropriate symptom. If speed sensor DTCs are

present, perform their respective test first.

>> Go To 2

CHECK IF ENGINE MECHANICAL PROBLEMS ARE PRESENT

Determine if any Engine mechanical problems are present.

Are there any Engine mechanical problems present?

Yes

>> Repair engine as necessary. Refer to 9 - ENGINE-SERVICE INFORMATION for the appropriate repair

procedures.

Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

>> Go To 3

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AUTOMATIC TRANSMISSION NAG1 - ELECTRICAL DIAGNOSTICS

CHECK IF TRANSMISSION MECHANICAL PROBLEMS ARE PRESENT

Determine if any Transmission mechanical problems are present.

Turn the ignition off to the lock position.

Remove the Transmission Oil Pan and inspect for excessuve debris or a plugged Transmission Oil Filter. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1/FILTER - STANDARD PROCEDURE).

Is there any debris, plugged Transmission Oil Filter, or signs of an internal transmission problem?

Yes

>> Repair Transmission as necessary. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 -

REMOVAL).

Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

>> Go To 4

TEST DRIVE VEHICLE

NOTE: The Engine and Transmission must not have mechanical problems and be operating normally before
proceeding with this test.
Replace and program the Powertrain Control Module (PCM) per the Service Information. Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/POWERTRAIN CONTROL MODULE for the appropriate service procedures.

Reassemble any previously disconnected connectors and/or components.

With the scan tool, erase Transmission DTCs.

Road test the vehicle.

With the scan tool, read Transmission DTCs.

Did DTC P0219-ENGINE OVERSPEED reset?

Yes

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

damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems
are found, replace the TCM per the Service Information. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION CONTROL MODULE - DESCRIPTION)

Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

>> Test Complete

Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

AUTOMATIC TRANSMISSION NAG1 - ELECTRICAL DIAGNOSTICS

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