Operation CHARM: Car repair manuals for everyone.

0218







0218-ELECTRONIC THROTTLE CONTROL SYSTEM - LOW VOLTAGE





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 Throttle Plate does not open far enough or does not return to Limp Home Position at the end of this test, this DTC will set. One trip fault. 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
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.
Does the Throttle Plate move smoothly?

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 Powertrain Verification Test. Powertrain Verification Test.

3. TP SENSOR NO.1 AND TP SENSOR NO.2 BOTH EQUAL 2.5 VOLTS
With a scan tool, perform the ETC Throttle Follower test while reading 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 Powertrain Verification Test. Powertrain Verification Test.

No

- Go to 4

4. ETC MOTOR (+) CIRCUIT OPEN




Turn the ignition off.
Measure the resistance of the ETC Motor (+) circuit from the Throttle Body harness connector to the PCM harness connector.
Is the resistance below 5.0 ohms?

Yes

- Go to 5

No

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

5. ETC MOTOR (-) CIRCUIT OPEN




Measure the resistance of the ETC Motor (-) circuit from the Throttle Body harness connector to the PCM harness connector.
Is the resistance below 5.0 ohms?

Yes

- Go to 6

No

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

6. ETC MOTOR (+) CIRCUIT SHORTED TO GROUND




Measure the resistance between a known good ground and the ETC Motor (+) circuit at the Throttle Body harness connector.
Is the resistance below 100 ohms?

Yes

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

No

- Go to 7

7. ETC MOTOR (-) CIRCUIT SHORTED TO GROUND




Measure the resistance between a known good ground and the ETC Motor (-) circuit at the Throttle Body harness connector.
Is the resistance below 100 ohms?

Yes

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

No

- Go to 8

8. POWERTRAIN CONTROL MODULE (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.