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For 1990-2009 cars only

DTC P0704 6.6L/LB7


Object Number: 1362511  Size: LF
Master Electrical Component List
Manual Transmission Schematics
OBD II Symbol Description Notice

Circuit Description

Battery voltage is supplied from the brake 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.

When the engine control module (ECM) detects a large number of gear changes without detecting a clutch switch transition, DTC P0704 sets. DTC P0704 is a type C DTC.

Conditions for Running the DTC

No VSS DTC P0500.

Conditions for Setting the DTC

The ECM detects 7 changes in vehicle speed from 0 km/h (0 mph) to above 38 km/h (24 mph) and then back to 0 km/h (0 mph) without the ECM detecting a clutch pedal transition.

Action Taken When the DTC Sets

    •  The ECM does not illuminate the malfunction indicator lamp (MIL).
    • The ECM disables cruise control.
    • The ECM disables power take-off.
    • The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM records this information as Freeze Frame and Failure Records.
    • The ECM stores DTC P0704 in ECM history.

Conditions for Clearing the MIL/DTC

    • A scan tool can clear the MIL/DTC.
    • The ECM clears the DTC from ECM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
    • The ECM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the ECM.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check - Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls in Engine Controls - 6.6L (LB7)

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 - 6.6L (LB7)

Go to Step 3

3

Inspect the adjustment of the clutch pedal position switch. Refer to Clutch Pedal Position Switch Replacement in Clutch.

Did you find and correct a condition?

--

Go to Step 14

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Caution: Refer to SIR Caution in the Preface section.

  3. Disconnect the clutch pedal position switch connector.
  4. Measure the voltage between Pin B of the clutch pedal position switch electrical connector and ground.

Does the DMM indicate the specified value?

B+

Go to Step 5

Go to Step 11

5

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

Does the scan tool display that the clutch is released?

--

Go to Step 8

Go to Step 6

6

  1. Turn OFF the ignition.
  2. Disconnect the ECM connector C1. Refer to Engine Control Module Replacement in Engine Controls - 6.6L (LB7).
  3. Use the DMM in order to test for continuity on the clutch pedal switch signal circuit between Pin A of the clutch pedal position switch and Pin 35 of the ECM connector C1. Refer to Testing for Continuity in Wiring Systems.

Did you detect continuity?

--

Go to Step 7

Go to Step 10

7

Use the DMM in order to test for continuity between Pin A of the clutch pedal position switch and ground. Refer to Testing for Continuity in Wiring Systems.

Did you detect continuity?

--

Go to Step 10

Go to Step 9

8

  1. Inspect for a loose connection at the clutch pedal position switch connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. Repair the condition as necessary. Refer to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 12

9

  1. Inspect for a loose connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. Repair the condition as necessary. Refer to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

10

Repair the open or short to ground in the clutch position switch signal circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 14

--

11

Repair the open in the clutch position switch feed circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 14

--

12

Replace the clutch pedal position switch. Refer to Clutch Pedal Position Switch Replacement in Clutch.

Is the action complete?

--

Go to Step 14

--

13

Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls - 6.6L (LB7).

Is the action complete?

--

Go to Step 14

--

14

  1. Select the DTC.
  2. Select Clear Info.
  3. Operate the vehicle from 0 km/h (0 mph) to above 38 km/h (24 mph) then back to 0 km/h (0 mph) 7 times.
  4. Select Specific DTC.
  5. Enter DTC P0704.

Has the test run and passed?

--

Go to Step 15

Go to Step 2

15

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 - 6.6L (LB7)

System OK