Circuit Description
The transmission control module (TCM) monitors the status of the pressure switches at start-up, in order to detect the presence of hydraulic pressure.
DTC P0701 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0701 Transmission Control System Performance
Conditions for Running the DTC
| • | The components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts. |
| • | Engine speed is greater than 200 RPM and less than 7,500 RPM for 5 seconds. |
Conditions for Setting the DTC
DTC P0701 sets when the TCM detects the following conditions:
| • | Transmission fluid temperature is greater than -25°C (-13°F). |
| • | All pressure switches do not indicate pressure at start-up. |
| • | Engine speed is greater than 500 RPM for 6 seconds or 400 RPM for 15 seconds. |
| • | Forward or REVERSE range is selected. |
Action Taken When the DTC Sets
| • | The TCM does not illuminate the malfunction indicator lamp (MIL). |
| • | DTC P0701 is stored in TCM history. |
| • | The TCM inhibits torque converter clutch (TCC) engagement. |
Conditions for Clearing the DTC
A scan tool can clear the code from TCM history. The TCM automatically clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without failure.
Diagnostic Aids
| • | Inspect the wiring for poor electrical connections at the TCM. Inspect for the following conditions: |
| - | A bent terminal |
| - | A backed-out terminal |
| - | A damaged terminal |
| - | Poor terminal tension |
| - | A chafed wire |
| - | A broken wire inside the insulation |
| • | When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. |
| • | You may have to drive the vehicle in order to experience a condition. |
| • | DTC P0701 may be logged if a forward or REVERSE range is selected immediately after the engine is started, and before the TCM detects pressure at the switches, 2-6 seconds after the engine starts. |
| • | A plugged control main filter may cause DTC P0701 to set. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Automatic Transmission Controls Schematics | |||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||||||
2 |
Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Is the transmission fluid level correct? | Go to Step 3 | Go to Step 4 | ||||||||
3 | DTC P0701 can set after performing fluid service and filter change, after replacement of the pressure switch manifold (PSM), or after a long period of storage. Have any of these conditions occurred? | Go to Step 7 | Go to Step 5 | ||||||||
4 | Add fluid to the proper level. Is the fluid at the appropriate level? | Go to Step 5 | -- | ||||||||
Measure line pressure. Refer to Line Pressure Check . Is the pressure within the specified value? | Go to Step 7 | Go to Step 6 | |||||||||
6 | No main pressure at idle may be an indication of the following conditions:
Did you find the reason for a no line pressure condition and was it repaired? | Go to Step 7 | |||||||||
7 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | Go to Step 8 | Go to Step 2 | ||||||||
8 | 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? | System OK | |||||||||
