0188
0188-ELECTRONIC THROTTLE CONTROL SYSTEM - OUTPUT STAGE
For a complete wiring diagram Consult Diagrams/Electrical.
- 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.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.
Diagnostic Test
1. ACTIVE DTC
NOTE: If the 0188 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.
Ignition on, engine not running.
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 *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking for an Intermittent DTC.
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. Powertrain Verification Test.
No
- Go To 3
3. ETC MOTOR (+) CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Throttle Body harness connector.
Disconnect the PCM harness connector.
Ignition on, engine not running.
Measure the voltage on the ETC Motor (+) circuit at the Throttle Body harness connector.
Is there any voltage present?
Yes
- Repair the short to voltage on the ETC Motor (+) circuit.
- Perform the Powertrain Verification Test. Powertrain Verification Test.
No
- Go To 4
4. ETC MOTOR (-) CIRCUIT SHORTED TO VOLTAGE
Measure the voltage on the ETC Motor (-) circuit at the Throttle Body harness connector.
Is there any voltage present?
Yes
- Repair the short to voltage in the ETC Motor (-) circuit.
- Perform the Powertrain Verification Test. Powertrain Verification Test.
No
- Go To 5
5. ETC MOTOR (+) CIRCUIT SHORTED TO THE ETC MOTOR (-) CIRCUIT
Measure the resistance between the ETC Motor (+) circuit and the ETC Motor (-) circuit at the Throttle Body harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the short to between the ETC Motor (+) circuit and the ETC Motor (-) circuit.
- Perform the Powertrain Verification Test. Powertrain Verification Test.
No
- Go To 6
6. 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 7
No
- Repair the open in the ETC Motor (+) circuit.
- Perform the Powertrain Verification Test. Powertrain Verification Test.
7. ETC MOTOR (+) CIRCUIT SHORTED TO GROUND
Measure the resistance between 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. 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 9
No
- Repair the open in the ETC Motor (-) circuit.
- Perform the Powertrain Verification Test. Powertrain Verification Test.
9. ETC MOTOR (-) CIRCUIT SHORTED TO GROUND
Measure the resistance between 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 10
10. ETC MOTOR
Connect the Throttle Body harness connector.
Measure the resistance of the ETC Motor between the ETC Motor (+) circuit and the ETC Motor (-) circuit at the PCM harness connector.
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. Powertrain Verification Test.
11. 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.