NGC

P2111-ELECTRONIC THROTTLE CONTROL SYSTEM - UNABLE TO CLOSE





For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
Ignition on and battery voltage greater than 10 volts.

- Set Condition:
Just after key on, the throttle is opened and closed to test the system. If the TP Sensor does not return to Limp Home Position at the end of this test, this DTC will set. One trip fault and the code will set within 5 seconds. ETC light is flashing.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview

Diagnostic Test

1. ACTIVE DTC
NOTE: Maximum engine speed could be reduced while this fault is active, it just depends where the throttle gets stuck.

Ignition on, engine not running.

NOTE: The PCM tests the ETC Motor by opening and closing the Throttle Plate before starting the engine. If during this test the Throttle plate does not return to the closed position this DTC sets.

With a scan tool select View DTCs.

NOTE: Diagnose any TP Sensor or 5-Volt Supply DTCs before continuing.

Is the DTC Active at this time?

Yes

- Go to 2

No

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking For An Intermittent DTC

2. THROTTLE PLATE STUCK OPEN
Turn the ignition off.

NOTE: The PCM tests the ETC Motor by opening and closing the Throttle Plate before starting the engine. If during this test the Throttle plate does not return to the closed position this DTC sets.

Remove the Air Cleaner Assembly from the Throttle Body.
Check for any signs of a foreign material causing the Throttle to remain open.
Using a scan tool, under System Tests, perform the ETC Throttle Follower Test.
Have an assistant watch the throttle plate to verify it moves during the test.
Does the Throttle Plate move?

Yes

- Go to 3

No

- Remove the debris if possible or replace the Throttle Body Assembly if signs of physical damage are present. Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, use a scan tool and perform the ETC RELEARN function.
- Perform the PCM Verification Test. Powertrain Verification Test

3. TP SIGNAL 1 AND TP SIGNAL 2 BOTH EQUAL 2.5 VOLTS
With a scan tool, perform the ETC Throttle Follower test while monitoring both TP Sensor voltage readings.
Are both TP Sensor readings stuck at 2.5 volts?

Yes

- Check the TP Sensor Signal circuits for excessive resistance, being shorted to each other, or shorted to the Sensor Return circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 4

4. (K124) ETC MOTOR (+) CIRCUIT SHORTED TO VOLTAGE




Turn the ignition off.
Disconnect the Throttle Body harness connector.
Disconnect the C2 PCM harness connector.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform the diagnostics.

Ignition on, engine not running.
Measure the voltage on the (K124) ETC Motor (+) circuit at the appropriate terminal of special tool #8815.
Is there any voltage present?

Yes

- Repair the short to voltage on the (K124) ETC Motor (+) circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 5

5. (K124) ETC MOTOR (+) CIRCUIT OPEN




Turn the ignition off.
Measure the resistance of the (K124) ETC Motor (+) circuit from the Throttle Body harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go to 6

No

- Repair the open in the (K124) ETC Motor (+) circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

6. (K126) ETC MOTOR (-) CIRCUIT OPEN




Measure the resistance of the (K126) ETC Motor (-) circuit from the Throttle Body harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go to 7

No

- Repair the open in the (K126) ETC Motor (-) circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

7. (K124) ETC MOTOR (+) CIRCUIT SHORTED TO GROUND




Measure the resistance between a known good ground and the (K124) ETC Motor (+) circuit at the appropriate terminal of special tool #8815.
Is the resistance below 100 ohms?

Yes

- Repair the short to ground in the (K124) ETC Motor (+) circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 8

8. (K126) ETC MOTOR (-) CIRCUIT SHORTED TO GROUND




Measure the resistance between a known good ground and the (K126) ETC Motor (-) circuit at the appropriate terminal of special tool #8815.
Is the resistance below 100 ohms?

Yes

- Repair the short to ground in the (K126) ETC Motor (-) circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 9

9. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Throttle Body and the Powertrain Control Module connectors.
Search for any Technical Service Bulletins that may apply.
Were there any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Replace and program the Powertrain Control Module.
- Perform the PCM Verification Test. Powertrain Verification Test