P2100-ELECTRONIC THROTTLE CONTROL MOTOR CIRCUIT
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the ignition on and the ETC Motor is not in Limp Home mode.
- Set Condition:
When the PCM detects an internal error or a short between the ETC Motor- and ETC Motor + circuits in the ETC Motor Driver. One trip fault. ETC light is flashing.
| Possible Causes |
| THROTTLE PLATE / BORE INSPECTION |
| (K124) ETC POSITIVE CIRCUIT SHORTED TO BATTERY VOLTAGE |
| (K126) ETC NEGATIVE CIRCUIT SHORTED TO BATTERY VOLTAGE |
| (K124) ETC POSITIVE CIRCUIT SHORTED TO THE (K126) ETC NEGATIVE CIRCUIT |
| (K124) ETC POSITIVE CIRCUIT OPEN |
| (K124) ETC POSITIVE CIRCUIT SHORTED TO GROUND |
| (K126) ETC NEGATIVE CIRCUIT OPEN |
| (K126) ETC NEGATIVE CIRCUIT SHORTED TO GROUND |
| LOW BATTERY VOLTAGE |
| ETC MOTOR/THROTTLE BODY |
| PCM |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
Diagnostic Test
1. ACTIVE DTCIgnition on, engine not running.
NOTE: When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode.
NOTE: If the P2100 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.
NOTE: Low battery voltage can also cause excessive current draw, in very hot and very cold ambient temperatures. Make sure the battery can pass a load test before continuing.
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
- Go To 2
No
- Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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
- 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. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 3
3. (K124) ETC POSITIVE 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 the diagnostics.
With a 12-volt test light connected to ground, probe the (K124) ETC Positive circuit at the appropriate terminal of special tool #8815.
Does the test light illuminate brightly?
Yes
- Repair the short to battery voltage on the (K124) ETC Positive circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 4
4. (K126) ETC NEGATIVE CIRCUIT SHORTED TO BATTERY VOLTAGE
Using a 12-volt test light connected to ground, probe the (K126) ETC Negative circuit at the appropriate terminal of special tool #8815.
Does the test light illuminate brightly?
Yes
- Repair the short to battery voltage in the (K126) ETC Negative circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 5
5. (K124) ETC POSITIVE CIRCUIT SHORTED TO THE (K126) ETC NEGATIVE CIRCUIT
Measure the resistance between the (K124) ETC Positive circuit and the (K126) ETC Negative circuit at the appropriate terminals of special tool #8815.
Is the resistance below 100 ohms?
Yes
- Repair the short to between the (K124) ETC Positive circuit and the (K126) ETC Negative circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 6
6. (K124) ETC POSITIVE CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (K124) ETC Positive 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 (K124) ETC Positive circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
7. (K124) ETC POSITIVE CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K124) ETC Positive circuit between the appropriate terminals of special tool #8815.
Is the resistance below 100 ohms?
Yes
- Repair the short to ground in the (K124) ETC Positive circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 8
8. (K126) ETC NEGATIVE CIRCUIT OPEN
Measure the resistance of the (K126) ETC Negative 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 9
No
- Repair the open in the (K126) ETC Negative circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
9. (K126) ETC NEGATIVE CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K126) ETC Negative circuit using the appropriate terminal of special tool #8815.
Is the resistance below 100 ohms?
Yes
- Repair the short to ground in the (K126) ETC Negative circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 10
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 Positive circuit and the (K126) ETC Negative circuit at the appropriate terminals of special tool #8815.
Is the resistance between 2.5 and 25 ohms at closed throttle?
Yes
- Go To 11
No
- 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. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Replace and program the Powertrain Control Module per Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)