P2118-ELECTRONIC THROTTLE CONTROL MOTOR CIRCUIT





For a complete wiring diagram Refer to Section 8W.



Possible Causes
THROTTLE PLATE / BORE INSPECTION
(K124) ETC MOTOR (+) CIRCUIT SHORTED TO BATTERY VOLTAGE
(K126) ETC MOTOR (-) CIRCUIT SHORTED TO BATTERY VOLTAGE
(K124) ETC MOTOR (+) CIRCUIT SHORTED TO THE (K126) ETC MOTOR (-) CIRCUIT
(K124) ETC MOTOR (+) CIRCUIT OPEN
(K124) ETC MOTOR (+) CIRCUIT SHORTED TO GROUND
(K126) ETC MOTOR (-) CIRCUIT OPEN
(K126) ETC MOTOR (-) CIRCUIT SHORTED TO GROUND
ETC MOTOR
PCM


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).



Diagnostic Test

1. ACTIVE DTC

NOTE: When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode.


Ignition on, engine not running.

NOTE: If the P2118 is intermittent, it is possible that the controller is overheating in extreme hot temperatures, and this is considered a normal protection operation. No repair is necessary.


With a scan tool, select View DTCs.
Look closely at the temperatures at which this DTC set.

Is the DTC Active at this time?

Yes


No

2. THROTTLE PLATE INSPECTION

Turn the ignition off.
Remove the Air Cleaner Assembly from the Throttle Body.
Check for any signs of a foreign material (ice or dirt) on the Throttle Plate or in the bore causing the Throttle Plate to stick.

Were any signs of foreign material or scoring of the throttle plate or bore found?

Yes


No

3. (K124) ETC MOTOR (+) CIRCUIT SHORTED TO BATTERY VOLTAGE



Turn the ignition off.
Disconnect the Throttle Body harness connector.
Disconnect the C2 PCM harness connector.
Ignition on, engine not running.

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.


With a 12-volt test light connected to ground, probe the (K124) ETC Motor (+) circuit at the appropriate terminal of special tool #8815.

Does the test light illuminate brightly?

Yes


No

4. (K126) ETC MOTOR (-) CIRCUIT SHORTED TO BATTERY VOLTAGE



Using a 12-volt test light connected to ground, probe the (K126) ETC Motor (-) circuit at the appropriate terminal of special tool #8815.

Does the test light illuminate brightly?

Yes


No

5. (K124) ETC MOTOR (+) CIRCUIT SHORTED TO THE (K126) ETC MOTOR (-) CIRCUIT



Measure the resistance between the (K124) ETC Motor (+) circuit and the (K126) ETC Motor (-) circuit at the appropriate terminals of special tool #8815.

Is the resistance below 100 ohms?

Yes


No

6. (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


No

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



Measure the resistance between ground and the (K124) ETC Motor (+) circuit between the appropriate terminals of special tool #8815.

Is the resistance below 100 ohms?

Yes


No

8. (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


No

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



Measure the resistance between ground and the (K126) ETC Motor (-) circuit between the appropriate terminals of special tool #8815.

Is the resistance below 100 ohms?

Yes


No

10. ETC MOTOR


NOTE: Take the following measurement using special tool #8815 to avoid possible damage to the Throttle Body harness connector.


Measure the resistance of the ETC Motor between the (K124) ETC Motor (+) circuit and the (K126) ETC Motor (-) circuit at the appropriate terminals of special tool #8815.

Is the resistance between 2.5 and 25 ohms at closed throttle?

Yes


No

11. 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


No