Transmission Control Module (TCM) - NAG1

P0219-ENGINE OVERSPEED

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Transmission Control Module (TCM) monitors the engine speed over the CAN bus. If the engine speed is greater than a calibrated limit (see table), 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 transmission gear into neutral to protect the engine and transmission from damage. The transmission will remain in neutral and will not be re-evaluated 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 message received at least once, and the CAN Bus Circuit and Engine CAN Message Missing are not active.

- Set Condition:
Engine speed is greater than a calibrated limit (see table).









Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding. NAG1 Pre-Diagnostic Troubleshooting Procedure

1. CHECK FOR OTHER TRANSMISSION DTCS
1. 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

- Diagnose and repair the DTC(s). If speed sensor DTCs are present, perform their respective test first.

No

- Go To 2

2. CHECK FOR ENGINE DTCS
1. With the scan tool, check for engine DTCs.

Are there any engine DTCs present?

Yes

- Diagnose and repair the DTC(s).

No

- Go To 3

3. CHECK IF ENGINE MECHANICAL PROBLEMS ARE PRESENT
1. 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. NAG1 Transmission Verification Test

No

- Go To 4

4. CHECK IF TRANSMISSION MECHANICAL PROBLEMS ARE PRESENT
1. Determine if any Transmission mechanical problems are present.
2. Turn the ignition off to the lock position.
3. Remove the Transmission Oil Pan and inspect for excessive debris or a plugged Transmission Oil Filter.

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

Yes

- Repair Transmission as necessary.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test

No

- Go To 5

5. TEST DRIVE VEHICLE

NOTE: The Engine and Transmission must not have mechanical problems and be operating normally before proceeding with this test.

1. Replace and program the Powertrain Control Module (PCM).
2. Reassemble any previously disconnected connectors and/or components.
3. With the scan tool, erase Transmission DTCs.
4. Road test the vehicle.
5. 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 and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the TCM.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test

No

- Test Complete
- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test