Circuit Description
Battery voltage is supplied from the Engine Ignition 1 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 sets. 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 vehicle speed goes from 0 km/h (0 mph) to greater than 39 km/h (24 mph) and back to 0 km/h (0 mph) for 2 seconds without the PCM detecting a clutch transition. |
| • | This must occur 7 times before the diagnostic reports a fault. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive drive trip that the diagnostic runs and fails. |
| • | Cruise control is disabled. |
| • | The PCM records the operating conditions at the time when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records. |
| • | The PCM stores P0704 in PCM history. |
Conditions for Clearing the MIL/DTC
| • | The DTC clears when the diagnostic runs and does not fail. |
| • | A History DTC clears after 40 consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures. |
| • | Use a scan tool in order to clear the MIL/DTC. |
Diagnostic Aids
Important:
• Remove any debris from the PCM connector surfaces before servicing
the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the
module. Ensure that the gaskets are installed correctly. The gaskets prevent
contaminate intrusion into the PCM. • For any test that requires probing the PCM or a component harness
connector, use the J 35616
GM terminal test kit. Using this kit prevents damage to the harness/component
terminals. Refer to
Using Connector Test Adapters
in Wiring Systems.
For clutch switch adjustment refer to Clutch Pedal Position Switch Replacement in Clutch.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step ensures that the technician has performed a Diagnostic System Check on the Manual Transmission System.
-
This test confirms if the scan tool is receiving a clutch switch position signal.
-
This step inspects the clutch pedal connector and adjustment.
-
This step tests for a short to ground.
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This step tests for voltage to the fuse.
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This step tests for voltage to the clutch pedal position switch.
-
This step tests the clutch pedal position switch.
-
This step tests the Clutch Pedal Position switch signal circuit.
-
This step tests the Ignition 1 Voltage circuit for a short to ground.
-
This step tests the Clutch Pedal Position switch signal circuit for a ground.
-
This step ensures that the technician has verified the system is operating normally.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 5.7L | |
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 - 5.7L | Go to Step 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 | |
Is the Engine Ignition 1 fuse open? | -- | Go to Step 9 | Go to Step 5 | |
Does the DMM indicate the specified value? | B+ | Go to Step 6 | Go to Step 12 | |
Does the DMM indicate the specified value? | B+ | Go to Step 7 | Go to Step 13 | |
Does the scan tool parameter display applied and released? | -- | Go to Step 15 | Go to Step 8 | |
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 | |
Is the Ignition 1 Voltage circuit grounded? | -- | Go to Step 13 | Go to Step 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 |
Important: Voltage to this fuse is run through the Ignition relay. Refer to Power Distribution Schematics in Wiring Systems. Repair the Power Distribution circuit to the Engine Ignition 1 fuse. Did you complete the repair? | -- | Go to Step 17 | -- |
13 | Repair the open, high resistance or short to ground in the Ignition 1 Voltage circuit or a parallel circuit that uses the 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. Refer to Clutch Pedal Position Switch Replacement . Is the action complete? | -- | Go to Step 17 | -- |
16 | Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 5.7L. Is the action complete? | -- | Go to Step 17 | -- |
Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 18 | Go to Step 2 | |
18 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 5.7L | System OK |
