Circuit Description
The Clutch Anticipate Switch input allows the PCM to adjust the IAC 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 IAC counts. This is done to avoid a possible RPM flare caused by the sudden change in engine load.
Conditions for Setting the DTC
| • | Vehicle speed is greater than 0. |
| • | Engine load and engine speed acceleration indicate that the vehicle is in gear. |
| • | The Clutch Anticipate Switch input is not grounded (clutch disengaged). |
| • | Above conditions must be present for longer than 15 seconds. |
OR
| • | Changes in the vehicle speed to engine speed ratio indicate that more than 20 gear changes have occurred. |
| • | The Clutch Anticipate Switch state did not change. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the MIL during the second key cycle in which the DTC sets. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present. |
| • | A history DTC P0704 will clear after 40 consecutive warm-up cycles have occurred without a fault. |
| • | DTC P0704 can be cleared by using the scan tool Clear Information function or by disconnecting the PCM battery feed. |
Diagnostic Aids
Check for the following conditions:
| • | Poor connection at PCM - Inspect harness connectors for the following items: |
| - | Backed out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Poor terminal to wire connections |
| • | Damaged harness - Inspect the wiring harness for damage. If the harness appears to be OK, observe the Clutch Anticipate Switch display on the scan tool while moving connectors and wiring harnesses related to the switch. A change in the display will indicate the location of the fault. Review the Fail Records vehicle mileage since the diagnostic test last failed. This may help determine how often the condition that caused the DTC to be set occurs. |
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table:
-
This step checks the true state of the clutch pedal switch.
-
This step checks the integrity of the Clutch Anticpate Switch input circuit.
-
This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||
Does the Clutch Pedal Switch display Released? | -- | |||||||
3 | Depress the clutch pedal while observing the Clutch Pedal Switch display on the scan tool. Does the Clutch Pedal Switch display change to Applied? | -- | Go to Diagnostic Aids | |||||
4 |
Does the Clutch Pedal Switch display change to Applied? | -- | ||||||
5 |
Is the test light ON? | -- | ||||||
6 |
Is the test light ON? | -- | ||||||
Does the Clutch Pedal Switch display Released? | -- | |||||||
8 |
Was a problem found? | -- | ||||||
9 | Locate and repair short to ground in Clutch Anticipate Switch signal circuit. Refer to Repair Procedures in Electrical Diagnosis. Is action complete? | -- | -- | |||||
10 | Locate and repair open in Clutch Anticipate Switch ground circuit. Refer to Repair Procedures in Electrical Diagnosis. Is action complete? | -- | -- | |||||
11 |
Was a problem found? | -- | ||||||
12 |
Was a problem found? | -- | ||||||
13 | Replace the Clutch Anticipate Switch. Refer to Manual Transmission Shift Anticipate Switch Replacement . Is action complete? | -- | -- | |||||
14 |
Was a problem found? | -- | ||||||
Replace the PCM. Important: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | -- | ||||||
16 |
Does the Clutch Pedal Switch display Released? | -- | ||||||
17 | Depress the clutch pedal while observing the Clutch Pedal Switch display on the scan tool. Does the Clutch Pedal Switch display change to Applied? | -- | System OK |
