Circuit Description
The clutch anticipate switch input allows the PCM to adjust the idle when the manual transmission clutch is being disengaged. The PCM monitors the Clutch Anticipate Switch input; if a low voltage is monitored, the PCM considers the Clutch Anticipate Switch closed to ground (clutch engaged). When the ground at the Clutch Anticipate Switch input is interrupted (clutch being disengaged), the PCM will immediately decrease idle. This is done to avoid a possible RPM flare caused by the sudden change in engine load.
Conditions for Running the DTC
Engine load and engine speed acceleration indicate that the vehicle is in gear and moving.
Conditions for Setting the DTC
| • | The Clutch Anticipate Switch PCM input indicates that the clutch is engaged (clutch switch closed to ground). |
| • | Above conditions must be present for more than 3 minutes. |
OR
| • | Changes in the vehicle speed to engine speed ratio indicate that more than 70 gear changes have occurred. |
| • | The state of the Clutch Anticipate Switch did not change. |
Action Taken When the DTC Sets
| • | The PCM will not illuminate the malfunction indicator lamp (MIL). |
| • | The PCM will store conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records. |
Conditions for Clearing the MIL/DTC
| • | A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using a scan tool. |
Diagnostic Aids
Inspect for the following:
Many situations may lead to an intermittent condition. The following list is to be used as a guide to assist in detecting an intermittent:
Important: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Verify that the gaskets are installed correctly. The gaskets prevent intrusion of contaminates.
| • | Inspect the harness connector for the following conditions: |
| - | Loose terminal connections |
| - | Backed out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Faulty terminal to wire connections--Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and Connector Repairs in Wiring Systems. |
| • | Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Circuit Testing , and Wiring Repairs in Wiring Systems for diagnosis and repair. |
| • | Inspect the PCM and the engine grounds for clean and secure connections. Refer to Wiring Systems for diagnosis and repair. |
If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set. Refer to Intermittent Conditions in Engine Controls.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This step tests the true state of the clutch pedal switch.
-
This step tests the integrity of the Clutch Anticipate Switch input circuit.
-
This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
Does the scan tool indicate Released? | -- | |||
3 | Depress the clutch pedal while observing the Clutch Anticipate Switch parameter on the scan tool. Does the parameter change to Applied? | -- | Go to Diagnostic Aids | |
4 | Disconnect the Clutch Anticipate Switch. Does the scan tool indicate Applied? | -- | ||
5 |
Does the test lamp illuminate? | -- | ||
6 |
Does the test lamp illuminate? | -- | ||
Does the scan tool indicate Released? | -- | |||
8 | Test the signal circuit for an open or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
9 | Repair the short to ground in the signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
10 | Repair open in the ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
11 | Test the Clutch Anticipate Switch adjustment. Refer to Manual Transmission Shift Anticipate Switch Replacement in Clutch. Did you find and correct the condition? | -- | ||
12 | Inspect for poor connections at the Clutch Anticipate Switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
13 | Replace the Clutch Anticipate Switch. Refer to Manual Transmission Shift Anticipate Switch Replacement in Clutch. Did you complete the replacement? | -- | -- | |
14 | Inspect for poor connections at PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
|
Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls. Did you complete the replacement? | -- | -- | ||
16 |
Does scan tool indicate Released? | -- | ||
17 | Depress the clutch pedal while observing the Clutch Anticipate Switch display on the scan tool. Does the parameter change to Applied? | -- | System OK |
