GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2004 🢒 Tracker - 4WD 🢒 Engine 🢒 Engine Controls - 2.0L 🢒 DTC P0973

Circuit Description

The shift solenoid 1 and the shift solenoid 2 operate together in order to electronically control the shifting of the transmission from 1st gear to 4th gear (overdrive). The powertrain control module (PCM) outputs the system voltage in order to perform the following actions:

    • Turn on (energize) either solenoid.
    • Turn off (de-energize) either solenoid.
        The PCM performs the above actions when necessary.

The transmission shifts with the combination of both solenoids turning on and off. The shift solenoid 1 is normally ON in the 1st and the 2nd gears. The shift solenoid 1 does not operate in the 3rd and the 4th gears. The shift solenoid 2 is normally ON in the 2nd and the 3rd gears. The shift solenoid 2 does not operate in the 1st and the 4th gears. The 4th gear (overdrive) is obtained when both of the shift solenoids are not operating.

The scan tool can be used to turn the shift solenoids on or off to verify proper operation. Monitoring the operation of the solenoids can also be done using the scan tool during a road test.

Conditions for Setting the DTC

The voltage detected at terminal 2 (2.0L) or terminal 6 (2.5L) is 2.0 volts or lower when the PCM commands the shift solenoid 1 ON.

Action Taken When the DTC Sets
    • DTC P0973 stores.
    • The PCM enters the fail-safe mode.
    • The malfunction indicator lamp (MIL) turns on.

During the fail-safe mode operation, 3rd gear operates instead of the 1st and the 2nd gears when the manual selector is in DRIVE range. The torque converter clutch does not engage.

Diagnostic Aids

Inspect for the following conditions:

    • A shorted shift solenoid 1
    • Faulty electrical circuits (short to ground) between the shift solenoid 1 and the PCM
    • A faulty PCM

The following conditions may cause an intermittent:

    • A reduced connection
    • Rubbed through wire insulation
    • A broken wire inside the insulation

Inspect the PCM harness connectors for the following conditions:

    • Backed out terminals
    • Improper mating
    • Broken locks
    • Improperly formed or damaged terminals
    • Reduced terminal-to-wire connections

If DTC P0973 cannot be duplicated, the information included in the Scan Tool Freeze Frame data may be useful in determining the vehicle operating conditions when the DTC set.

Refer to Wiring Repairs in Wiring Systems when repairing any wiring.

DTC Confirmation Procedure
  1. Turn the ignition switch to the LOCK position.
  2. Connect the scan tool to the data link connector (DLC).
  3. Turn the ignition switch ON.
  4. Use the scan tool in order to clear the following items:
    5. • DTC P0973
    • Any pending DTCs
  5. Start the engine.
  6. Apply the brake pedal firmly
  7. Shift the manual selector to DRIVE range.

    8. Remain in DRIVE range for 10 seconds.

  8. Release the brake, then accelerate the vehicle in DRIVE range.

    9. Continue driving for 10 seconds at 30 km/h (20 mph).

    Increase the vehicle speed to 80 km/h (50 mph) for 10 seconds.

  9. Stop the vehicle.
  10. Use the scan tool in order to test for a pending DTC.

Test Description

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

  1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. The scan tool creates an electronic copy of the data taken when the fault occurred. The information then stores in the scan tool for later reference.

    2.

  2. This step tests the shift solenoid internal coil resistance.

    3.

  3. This step tests for a short to ground in the shift solenoid circuit.

    4.

  4. This step inspects the condition of the transmission internal electrical harness for damage.

    5.

  5. This step tests for a faulty PCM.

Step

Action

Value(s)

Yes

No

1

Was the On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls in Engine Controls - 2.0L or Diagnostic System Check - Engine Controls in Engine Controls - 2.5L

2
  1. Install a scan tool.
  2. Turn the ignition to ON, leaving the engine OFF.
  3. Perform the scan tool Clear DTC Information function.
  4. Operate the vehicle within the Freeze Frame conditions as observed.

Does the scan tool display any other DTCs in addition to DTC P0973?

--

Go to the applicable DTC table

Go to Step 3

3

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the PCM connector C3.
  3. Use a DMM in order to measure the resistance between ground and the PCM harness connector C3 terminal 2 (2.0L) or terminal 6 (2.5L).

Is the resistance within the specified range?

11-16.6 ohms at 24°C (75°F)

Go to Step 6

Go to Step 4

4

  1. Disconnect the transmission shift solenoid connector at the transmission.
  2. Use the DMM in order to measure the resistance between ground and the PCM harness connector C3 terminal 2 (2.0L) or terminal 6 (2.5L).

Is the resistance equal to the specified value?

∞

Go to Step 5

Go to Step 7

5

  1. Remove the transmission oil pan.
  2. Inspect the terminals and internal harness for damage.
  3. Replace the shift solenoid if no damage exists.

Is the procedure complete?

--

Go to Step 10

--

6

  1. Install a known good PCM. Refer to Powertrain Control Module Replacement in Engine Controls-2.0L or Powertrain Control Module Replacement in Engine Controls-2.5L.
  2. Perform the DTC Confirmation Procedure.

Does DTC P0973 reset?

--

Go to Step 8

Go to Step 9

7

Repair the short to ground in the wire between the PCM and the shift solenoid 1.

Is the repair complete?

--

Go to Step 10

--

8

Refer to Diagnostic Aids for a possible intermittent condition.

Is the procedure complete?

--

Go to Step 10

--

9

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls-2.0L or Powertrain Control Module Replacement in Engine Controls-2.5L.

Is the procedure complete?

--

Go to Step 10

--

10
  1. Turn the ignition switch to the LOCK position.
  2. Reconnect all the connectors.
  3. Perform the DTC Confirmation Procedure.

Does the scan tool display any DTCs?

--

Go to the applicable DTC table

System OK