P2112

P2112-ELECTRONIC THROTTLE CONTROL - UNABLE TO OPEN





For a complete wiring diagram refer to 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.


Diagnostic Test


1. ACTIVE DTC

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.

Ignition on, engine not running.

With a scan tool select View DTCs.


NOTE: Diagnose any TP Sensor, Battery Voltage, and 5-volt Supply DTCs before continuing.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition


2. THROTTLE PLATE STUCK OPEN

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 open this DTC sets.

Turn the ignition off.

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. Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, use a scan tool and select the ETC RELEARN function.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


3. (K126) 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 diagnosis.

Ignition on, engine not running.

Measure the voltage on the (K126) ETC Motor (-) circuit at the appropriate terminal of special tool #8815.

Is there any voltage present?

Yes

- Repair the short to voltage on the (K126) ETC Motor (-) circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4


4. (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 5

No

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


5. (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 6

No

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


6. (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 POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 7


7. (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 POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 8


8. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test