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For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2006 🢒 VUE - AWD 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 DTC U0107

Circuit Description

The DTC U0107 Lost Communication With the Throttle Actuator Control (TAC) Module diagnostic monitors the communication between the TAC module and the powertrain control module (PCM). The TAC module and the PCM communicate on a serial data line. If the PCM can not communicate with the TAC module, DTC U0107 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC U0107 Lost Communication With the Throttle Actuator Control (TAC) Module

Conditions for Running the DTC
    • DTC P0122, P0123, P0222, P0223, P0641, P0651, P2100, P2101, P2108, P2122, P2123, P2127, P2128, P2135, P2138, and P2176 are not set.
    • The ignition is ON.
    • Battery voltage is at least 8 volts.
    • DTC U0107 runs continuously once the above conditions are met.

Conditions for Setting the DTC

Either of the conditions below is present for at least 250 milliseconds:

    • The PCM did not detect any signal on the serial data line.
    • The serial data signal is unreadable.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL).
    • The PCM records the operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC
    • The MIL turns OFF after 3 consecutively passing trips without a fault present.
    • A history DTC clears after 40 consecutive warm-up cycles without a fault.
    • Perform the scan tool Clear DTC Information function.

Test Description

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

  1. The Diagnostic System Check - Vehicle prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool, if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

    2.

  2. This step checks for an open in the ignition positive voltage supply to the TAC module.

    3.

  3. This step checks for an open in the TAC module electrical grounds. The TAC module can not operate correctly if there are faulty electrical grounds.

    4.

  4. After replacing the PCM, a new minimum throttle position and idle speed must also be established.

Step

Action

Value(s)

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn ON the ignition, leaving the engine OFF.
  2. Use the scan tool in order to clear the DTCs.
  3. Start and run the engine for 1 minute.

Is a DTC U0107 set?

--

Go to Step 4

Go to Step 3

3
  1. Use the scan tool in order to clear the DTCs.
  2. Start the engine.
  3. Operate the vehicle within the Freeze Frame conditions as specified or until the DTC U0107 diagnostic test has run.

Does the DTC run and pass?

--

Go to Step 4

Go to Intermittent Conditions

4

Is a DTC P2554 or P2555 also set?

--

Go to DTC P2554 or DTC P2555

Go to Step 5

5
  1. Turn OFF the ignition.
  2. Disconnect the throttle actuator control (TAC) module electrical connector.
  3. Connect a DMM to the ETC control circuit and a good ground.
  4. Turn ON the ignition, leaving the engine OFF.

Is the voltage at the specified value?

B+

Go to Step 6

Go to Step 10

6

Connect the DMM to the ETC signal circuit and a good ground.

Is the voltage at the specified value?

B+

Go to Step 7

Go to Step 11

7

Connect the DMM to the ignition positive voltage circuit and ground.

Is the voltage at the specified value?

B+

Go to Step 8

Go to Step 13

8

Probe each TAC module ground circuit with a test lamp connected to B+.

Did the test lamp illuminate on both ground circuits?

--

Go to Step 9

Go to Step 12

9
  1. Inspect for an open in the TAC motor inhibit circuit.
  2. Repair as necessary. Refer to Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 18

Go to Step 14

10

  1. Inspect for an open or a short in the ETC control circuit.
  2. Repair as necessary. Refer to Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 18

Go to Step 16

11
  1. Inspect for an open or a short in the ETC signal circuit.
  2. Repair as necessary. Refer to Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 18

Go to Step 16

12

Repair the open in the ground circuits of the TAC module. Refer to Wiring Repairs .

Did you complete the repair?

--

Go to Step 18

--

13

  1. Repair the open or the short to ground in the ETC ignition positive voltage circuit. Refer to Wiring Repairs .
  2. Replace the ETC fuse as necessary.

Did you complete the repair?

--

Go to Step 18

--

14
  1. Inspect for an intermittent or poor electrical connection at TAC module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
  2. Repair as necessary. Refer to Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 18

Go to Step 15

15
  1. Replace the TAC module. Refer to Throttle Body Assembly Replacement .
  2. Perform the idle learn procedure. Refer to Idle Learn .

Did you complete the replacement?

--

Go to Step 18

--

16
  1. Inspect for an intermittent or poor electrical connection at powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
  2. Repair as necessary. Refer to Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 18

Go to Step 17

17

  1. Replace the PCM. Refer to Control Module References for replacement, setup, and programming.
  2. Perform the idle learn procedure. Refer to Idle Learn .

Did you complete the replacement?

--

Go to Step 18

--

18
  1. Use the scan tool in order to clear the DTCs.
  2. Start the engine.
  3. Operate the vehicle within the Freeze Frame conditions as specified or until the DTC U0107 diagnostic test has run. Refer to the Test Description.

Does the DTC run and pass?

--

Go to Step 19

Go to Step 2

19

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK