GM Service Manual Online
For 1990-2009 cars only

Object Number: 548590  Size: SF
Engine Controls Components
Engine Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

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 stores 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

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Inspect for the following:

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

Important: :  Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

    • Loose terminal connection
       -  Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
       -  Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
    • Damaged harness--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 Wiring Repairs in Wiring Systems for diagnosis and repair.
    •  Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. This step tests the true state of the clutch pedal switch.

  2. This step tests the integrity of the Clutch Anticipate Switch input circuit.

  3. 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.

DTC P0704 - Clutch Switch Circuit

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn ON the ignition.
  2. With a scan tool, observe the Clutch Anticipate Switch parameter.

Does the scan tool indicate Released?

--

Go to Step 3

Go to Step 6

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

Go to Step 4

4

Disconnect the Clutch Anticipate Switch.

Does the scan tool indicate Applied?

--

Go to Step 13

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the PCM
  3. Probe the signal circuit at the PCM harness connector using a J 35616-200 test lamp that is connected to B+.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 15

6

  1. Disconnect the clutch pedal switch.
  2. Probe the ground circuit using a test lamp that is connected to B+.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 10

7

  1. Connect a fused jumper between the signal circuit and the ground circuit.
  2. With a scan tool, observe the clutch anticipate switch parameter.

Does the scan tool indicate Released?

--

Go to Step 11

Go to Step 8

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?

--

Go to Step 16

Go to Step 14

9

Repair the short to ground in the signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

10

Repair open in the ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

11

Test the Clutch Anticipate Switch adjustment. Refer to Manual Transmission Shift Anticipate Switch Replacement in Clutch.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

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?

--

Go to Step 16

Go to Step 13

13

Replace the Clutch Anticipate Switch. Refer to Manual Transmission Shift Anticipate Switch Replacement in Clutch.

Did you complete the replacement?

--

Go to Step 16

--

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?

--

Go to Step 16

Go to Step 15

15

Important: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Did you complete the replacement?

--

Go to Step 16

--

16

  1. Turn ON the ignition.
  2. With a scan tool, observe the clutch anticipate switch parameter.

Does scan tool indicate Released?

--

Go to Step 17

Go to Step 6

17

Depress the clutch pedal while observing the Clutch Anticipate Switch display on the scan tool.

Does the parameter change to Applied?

--

System OK

Go to Step 4