Diagnostic Test

1. With the scan tool, read all DTCs and record on the repair order.

   Are any other Gear Ratio Error, TCC Out of Range or Line Pressure related DTCs present?

   Yes 

   • Repair any Gear Ratio Error, TCC Out of Range or Line Pressure DTCs before continuing the P0933 diagnostics. If P0934 or P0935 is set, perform that diagnostic procedure first. Refer to DIAGNOSTIC CODE INDEX .

   No 

   • Go To  2

1. Start the Engine.
2. With the scan tool, read the Line Pressure, Desired Line Pressure and the TPS degrees.
3. While firmly applying the brakes, place the shifter in reverse, then slowly press the accelerator pedal to a TPS angle of 15°.
4. Compare the Line Pressure reading to the Desired Line Pressure reading on the scan tool.

   Does the Line Pressure stay within ± 34 kPa (5 psi) of the Desired Line Pressure?

   Yes 

   • Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .

   No 

   • Go To  3

1. Turn the ignition on.
2. With the scan tool, read the Line Pressure Sensor voltage while wiggling the wiring harness and connectors pertaining to the Line Pressure Sensor and the Transmission Solenoid/TRS Assembly.

   Did the voltage remain steady while wiggling the wiring harness and connectors?

   Yes 

   • Go To  4

   No 

   • Disconnect and properly reconnect the Line Pressure Sensor connector. Inspect terminals and repair as necessary.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

1. Turn the ignition off.
2. Disconnect the harness connector at the component of the circuit being tested. Note: The ECU harness connector should still be connected during this test step.
3. Turn the ignition on.
4. Set the DVOM to measure DC voltage.
5. Connect the negative lead of the DVOM to a known good ground.
6. With the positive lead of the DVOM, measure the voltage of the circuit being tested at the component harness connector.

Does the circuit have the proper voltage present?

Yes 

• Go To  8

No 

• Go To  5

1. Important:  The GPEC Diagnostic Adapter can add up to 1.5 Ohms of resistance to the circuit.
2. Connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
   1. The ignition must be off when checking the continuity of a circuit.
   2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
   3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note:  The meter leads can add resistance to the measurement value.
   4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
   5. Connect the other lead to the circuit being tested at the GPEC Diagnostic Adapter and measure the resistance of the circuit.

   Is the resistance below 3.0 Ohms?

   Yes 

   • Go To  6

   No 

   • Repair the circuit for an open or high resistance.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

1. Disconnect the PCM C2 harness connector.
2. Measure the resistance between the (F856) Line Pressure Sensor 5 Volt Supply circuit and the (K400) Sensor Ground circuit at the Line Pressure Sensor harness connector.

   Is the resistance above 10k Ohms?

   Yes 

   • Go To  7

   No 

   • Repair the (F856) 5 Volt Supply circuit for a short to the (K400) Sensor Ground circuit.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

1. The ignition must be off when checking a circuit for continuity to ground.
2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
3. Connect the negative lead of the DVOM to a known good ground.
4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.

Is there continuity between ground and the circuit being tested?

Yes 

• Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
• Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

No 

• Go To  13

1. Turn the ignition off.
2. Disconnect the Line Pressure Sensor.
3. Turn the ignition on.
4. With the scan tool, read the Line Pressure Sensor signal voltage.

   Is the voltage above 4.8 volts?

   Yes 

   • Go To  11

   No 

   • Go To  9

1. Disconnect the PCM C2 harness connector.
2. Measure the resistance between the (T38) Line Pressure Sensor Signal circuit and the (K400) Sensor Ground circuit at the Line Pressure Sensor harness connector.

   Is the resistance above 10k Ohms?

   Yes 

   • Go To  10

   No 

   • Repair the (T38) Line Pressure Sensor Signal circuit for a short to the (K400) Sensor Ground circuit.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

1. The ignition must be off when checking a circuit for continuity to ground.
2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
3. Connect the negative lead of the DVOM to a known good ground.
4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.

Is there continuity between ground and the circuit being tested?

Yes 

• Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
• Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

No 

• Go To  13

1. Important:  The GPEC Diagnostic Adapter can add up to 1.5 Ohms of resistance to the circuit.
2. Connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
   1. The ignition must be off when checking the continuity of a circuit.
   2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
   3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note:  The meter leads can add resistance to the measurement value.
   4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
   5. Connect the other lead to the circuit being tested at the GPEC Diagnostic Adapter and measure the resistance of the circuit.

   Is the resistance below 3.0 Ohms?

   Yes 

   • Go To  12

   No 

   • Repair the circuit for an open or high resistance.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

1. Turn the ignition off.
2. Install the Line Pressure Adaptor (special tool #8259, Adapter, Pressure Test), and the 0-300 psi Pressure Gauge (special tool #C-3293-SP, Gauge, Pressure 0-300 P.S.I.).
3. Start the Engine in PARK.
4. Monitor the line pressure readings of both the scan tool and the pressure gauge and compare the two readings.

   Is the line pressure gauge reading within 34 kPa (5 psi) of the scan tool reading?

   Yes 

   NOTE:

   This transmission is equipped with a solenoid for the Torque Converter Clutch (TCC) that is a Variable Force Solenoid (VFS) with close tolerance Pressure/Inductance (PI) curve. It is necessary to update the TCC solenoid PI data in the PCM when replacing the TCC solenoid, Valve Body or Transmission assembly. This is done with the scan tool using the "Program Torque Converter Solenoid PI Curve" routine. The PI data is located on a 2-D BAR code etched on the body of the TCC solenoid. The data must be entered into the scan tool in order to upload the information to the PCM.

   When replacing the TCC solenoid or Valve Body, obtain the PI data before installing the transmission oil pan. When replacing the transmission, the PI data can be obtained from a 2-D bar code on the exterior of the new transmission. Early build transmissions will have the 2-D barcode label on the right side of the transmission case. Late build transmissions will have the label attached to a machined pad at the top of the case, near the rear of the transmission. If it is suspected that the valve body or TCC VFS has been replaced without uploading the correct PI data into the PCM, the transmission oil pan must be removed to retrieve the information from the 2-D bar code on the body of the TCC solenoid.

   • Repair internal Transmission and inspect the oil pump per the Service information and replace if necessary. If no problems are found, replace the Transmission Solenoid/TRS Assembly - possible cause is the Pressure Control Solenoid is stuck.
   • If the Valve Body or the TCC VFS solenoid is replaced, remove the external TCC VFS bar code label from the transmission case.
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

   No 

   • Replace the Line Pressure Sensor in accordance with the Service Information. Refer to SENSOR, VARIABLE LINE PRESSURE, REMOVAL AND INSTALLATION .
   • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

1. Disconnect all PCM harness connectors.
2. Disconnect the (special tool #10436, Adapter, GPEC Diagnostic) and remove from the vehicle.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
   • Proper connector installation.
   • Damaged connector locks.
   • Corrosion.
   • Other signs of water intrusion.
   • Weather seal damage (if equipped).
   • Bent terminals.
   • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
   • Terminals that have been pushed back into the connector cavity.
   • Perform a terminal drag test on each connector terminal to verify proper terminal tension.

   Repair any conditions that are found.

6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
11. With the scan tool, read PCM DTCs.

    Did the DTC return?

    Yes 

    NOTE:

    This transmission is equipped with a solenoid for the Torque Converter Clutch (TCC) that is a Variable Force Solenoid (VFS) with close tolerance Pressure/Inductance (PI) curve. If replacing the PCM, it is necessary to transfer the PI data from the old PCM to the new PCM using the scan tool. If the PCM being replaced is non-responsive, the PI data can be retrieved from a 2-D bar code on the exterior of the transmission case. This is done with the scan tool using the "Program Torque Converter Solenoid PI Curve" routine.

    Early build transmissions will have the 2-D barcode label on the right side of the transmission case. Late build transmissions will have the label attached to a machined pad at the top of the case, near the rear of the transmission. The data must be entered into the scan tool in order to upload the information to the PCM. In the event that the exterior BAR code is missing, or it is suspected that the valve body or TCC solenoid has been replaced without uploading the correct PI data into an existing PCM, the transmission oil pan must be removed to retrieve the information from the 2-D bar code on the body of the TCC solenoid.

    • Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the PCM in accordance with the Service Information. Refer to REMOVAL AND INSTALLATION .
    • With the scan tool, perform Quick Learn.
    • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .

    No 

    • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
    • Test complete.