GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Blazer - 4WD - RHD 🢒 DTC 🢒 DTC P0704

Circuit Description

Battery voltage is supplied from the ABS fuse to the clutch switch. The clutch switch is a normally closed switch. When the clutch pedal is released, the clutch pedal position switch signal circuit is pulled up to B+. When the clutch pedal is applied, the switch opens, and the voltage drops to 0 volts.

If the powertrain control module (PCM) detects a specified number of vehicle speed transitions without detecting a clutch switch transition, DTC P0704 will set. DTC P0704 is a type B DTC.

Conditions for Running the DTC

No vehicle speed sensor (VSS) DTC P0500.

Conditions for Setting the DTC

The PCM detects 7 changes in vehicle speed 0- 38 km/h (0-24 mph) without the PCM detecting a clutch pedal transition.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
    • The PCM disables cruise control.
    • The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM records this information as Freeze Frame and Failure Records.
    • The PCM stores DTC P0704 in PCM history.

Conditions for Clearing the MIL/DTC
    • The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
    • The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.
    •  A history DTC clears after 40 consecutive warm-up cycles, if no failures are present by this diagnostic or any other emission-related diagnostic.
    • A scan tool can clear the MIL/DTC.

Test Description

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

  1. This step ensures that the technician has performed a Diagnostic System Check on the Manual Transmission System.

  2. This test confirms if the scan tool is receiving a clutch switch position signal.

    3.

  3. This step inspects the clutch pedal connector and adjustment.

  4. This step tests for a short to ground.

    5.

  5. This step tests for voltage to the ABS fuse.

    6.

  6. This step tests for voltage to the clutch pedal position switch.

    7.

  7. This step tests the clutch pedal position switch.

    8.

  8. This step tests the Clutch Pedal Position switch signal circuit.

  9. This step tests the Ignition 3 Voltage circuit for a short to ground.

  10. This step tests the Clutch Pedal Position switch signal circuit for a ground.

    11.

  11. This step ensures that the technician has verified the system is operating normally.

Step

Action

Value(s)

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check - Manual Transmission?

--

Go to Step 2

Go to Diagnostic System Check - Manual Transmission

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool to monitor the clutch pedal position switch parameter.
  4. Apply and release the clutch pedal several times.

Does the scan tool indicate a change in state when the clutch pedal is either applied or released?

--

Go to Intermittent Conditions in Engine Controls - 4.3L

Go to Step 3

3

Inspect the adjustment of the clutch pedal position switch and the connector.

Does the clutch switch require adjustment or the connector require service?

--

Go to Step 11

Go to Step 4

4

Is the ABS fuse open?

--

Go to Step 9

Go to Step 5

5
  1. Turn the ignition switch to RUN.
  2. Using a DMM, measure voltage at the ABS fuse.

Does the DMM indicate the specified value?

B+

Go to Step 6

Go to Step 12

6
  1. Turn OFF the ignition.
  2. Disconnect the clutch pedal position switch connector.
  3. Turn the ignition switch to RUN.
  4. Using a DMM, measure the voltage at the Ignition 3 Voltage circuit.

Does the DMM indicate the specified value?

B+

Go to Step 7

Go to Step 13

7
  1. Use the scan tool to monitor the clutch pedal position switch parameter.
  2. Turn ON the ignition, with the engine OFF.
  3. Use a fused jumper wire to repeatedly connect and disconnect Pin E and Pin F of the clutch pedal position switch electrical connector.

Does the scan tool display that the clutch is applying and releasing?

--

Go to Step 15

Go to Step 8

8
  1. Turn the ignition switch OFF.
  2. Disconnect C1 at the PCM.
  3. Using the DMM, test for continuity and a short to voltage on the Clutch Pedal Position switch signal circuit.

Did you find a short to voltage, high resistance or an open on the Clutch Pedal Position switch signal circuit?

--

Go to Step 14

Go to Step 16

9
  1. Turn the ignition switch OFF.
  2. Remove the ABS fuse.
  3. Disconnect the clutch pedal position switch connector and C1 at the PCM.
  4. Using a DMM, test for a short to ground on the Ignition 3 Voltage circuit at the switch connector.

Is the Ignition 3 Voltage circuit grounded?

--

Go to Step 13

Go to Step 10

10

Using a DMM, test for a short to ground on the Clutch Pedal Position switch signal circuit at the switch connector.

Is the Clutch Pedal Position switch signal circuit grounded?

--

Go to Step 14

Go to Step 15

11

Adjust the clutch pedal position switch or repair the connector as necessary.

Did you complete the repair?

--

Go to Step 17

--

12

Repair the Power Distribution circuit to the ABS fuse.

Did you complete the repair?

--

Go to Step 17

--

13

Repair the open, high resistance or short to ground in the Ignition 3 Voltage circuit or a parallel circuit that uses the ABS fuse.

Did you complete the repair?

--

Go to Step 17

--

14

Repair the open, high resistance or short in the Clutch Pedal Position switch signal circuit.

Did you complete the repair?

--

Go to Step 17

--

15

Replace the clutch pedal position switch.

Is the action complete?

--

Go to Step 17

--

16

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 4.3L.

Is the action complete?

--

Go to Step 17

--

17

Operate the vehicle within the conditions for running the DTC.

Did DTC P0704 set?

--

Go to Step 2

System OK