P2100-ELECTRONIC THROTTLE CONTROL MOTOR CIRCUIT
P2100-ELECTRONIC THROTTLE CONTROL MOTOR CIRCUIT
For a complete wiring diagram, refer to the Wiring Information.
Theory of operation
The Electronic Throttle Control (ETC) Motor is controlled by the Powertrain Control Module (PCM). The DC motor located in the Throttle Body Assembly drives the throttle blade. In order to decrease idle speed, along with spark and fuel delivery changes the PCM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the PCM commands the throttle plate open allowing more air to pass the throttle plate.
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When Monitored:
With the ignition on and the ETC Motor is not in Limp mode.
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Set Condition:
When the Powertrain Control Module (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 VOLTAGE |
| (K126) ETC NEGATIVE CIRCUIT SHORTED TO 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 |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
| 1. | Ignition on, engine not running. |
| 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. |
| 2. | With the scan tool, read the active DTCs. |
| 3. | Look closely at the temperatures at which this DTC set. |
Is the DTC Active at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| 1. | Turn the ignition off. |
| 2. | Remove the Air Cleaner Assembly from the Throttle Body. |
| 3. | 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. (Refer to 14 - Fuel System/Fuel Injection/THROTTLE BODY - Removal) . 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 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Go To 3
3. (K124) ETC POSITIVE CIRCUIT SHORTED TO VOLTAGE
 |
| 1. | Turn the ignition off. |
| 2. | Disconnect the Throttle Body harness connector. |
| 3. | Disconnect the PCM C2 harness connector. |
| 4. | Ignition on, engine not running. |
| 5. | Measure the voltage on the (K124) ETC Positive circuit at the Throttle Body harness connector. |
Is there any voltage present?
Yes
- Repair the short to voltage on the (K124) ETC Positive circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
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Go To 4
4. (K126) ETC NEGATIVE CIRCUIT SHORTED TO VOLTAGE
 |
| 1. | Measure the voltage on the (K126) ETC Negative circuit at the Throttle Body harness connector. |
Is there any voltage present?
Yes
- Repair the short to voltage in the (K126) ETC Negative circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
-
Go To 5
5. (K124) ETC POSITIVE CIRCUIT SHORTED TO THE (K126) ETC NEGATIVE CIRCUIT
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| 1. | Turn the ignition off. |
| 2. | Measure the resistance between the (K124) ETC Positive circuit and the (K126) ETC Negative circuit at the Throttle Body harness connector. |
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 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
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Go To 6
6. (K124) ETC POSITIVE CIRCUIT OPEN
 |
| 1. | Measure the resistance of the (K124) ETC Positive circuit from the Throttle Body harness connector to the PCM C2 harness connector. |
Is the resistance below 5.0 Ohms?
Yes
- Go To 7
No
- Repair the open in the (K124) ETC Positive circuit.
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Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
7. (K124) ETC POSITIVE CIRCUIT SHORTED TO GROUND
 |
| 1. | Measure the resistance between ground and the (K124) ETC Positive circuit at the Throttle Body harness connector. |
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 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
-
Go To 8
8. (K126) ETC NEGATIVE CIRCUIT OPEN
 |
| 1. | Measure the resistance of the (K126) ETC Negative circuit from the Throttle Body harness connector to the PCM C2 harness connector. |
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 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
9. (K126) ETC NEGATIVE CIRCUIT SHORTED TO GROUND
 |
| 1. | Measure the resistance between ground and the (K126) ETC Negative circuit at the Throttle Body harness connector. |
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 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
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Go To 10
 |
| 1. | Reconnect the Throttle Body harness connector. |
| 2. | Measure the resistance of the ETC Motor between the (K124) ETC Positive circuit and the (K126) ETC Negative circuit at the PCM C2 harness connector. |
Is the resistance between 2.5 and 25 Ohms at closed throttle?
Yes
- Go To 11
No
- Replace the Throttle Body Assembly. (Refer to 14 - Fuel System/Fuel Injection/THROTTLE BODY - Removal) . Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, use a scan tool and select the ETC RELEARN function.
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Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
11. POWERTRAIN CONTROL MODULE (PCM)
| 1. | Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM). |
| 2. | Look for any chafed, pierced, pinched or partially broken wires. |
| 3. | Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. |
| 4. | Perform any Technical Service Bulletins that may apply. |
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Replace and program the Powertrain Control Module in accordance with the Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal) .
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).