Circuit Description
The Pressure Control Solenoid Valve (PC Sol. Valve) is a Transmission Control Module (TCM) controlled device that regulates the transmission line pressure. The TCM compares the Throttle Position (TP) Sensor voltage, engine RPM, and other inputs in order to determine the appropriate line pressure for a given load. The TCM regulates the pressure by applying a varying amperage to the PC Sol. Valve. The applied amperage can vary from 0.1 amps for maximum line pressure to 1.1 amps for minimum line pressure. The TCM monitors the circuit amperage.
If the TCM detects a PC duty cycle that exceeds 95% or is less than 1.9%, then DTC 73 sets.
Conditions for Setting the DTC
| • | No system voltage DTC 75. |
| • | The PC duty cycle exceeds 95% or is less than 1.9%. |
| • | All conditions met for 200 milliseconds (0.2 seconds). |
Action Taken When the DTC Sets
| • | The TCM does not illuminate the Malfunction Indicator Lamp (MIL). |
| • | The TCM disables the PC Sol. Valve, defaulting the transmission to maximum line pressure. |
| • | DTC 73 is stored in TCM history. |
Conditions for Clearing the DTC
| • | The TCM clears the DTC from Current to History when the fault condition(s) no longer exist and the ignition switch is cycled OFF and then ON. |
| • | A scan tool can clear the DTC from Current and History status. The TCM clears the DTC from the TCM history if the vehicle completes 40 ignition cycles without a failure reported. |
| • | The TCM cancels the DTC default actions when the fault no longer exists and the ignition is cycled OFF and then ON. |
Diagnostic Aids
| • | Inspect the wiring at the TCM, the transmission connector and all other circuit connecting points 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 |
| - | Moisture intrusion |
| - | Corrosion |
| • | When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. |
| • | Inspect for any transmission DTCs that may have reset. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests the ability of the TCM to command the PC Sol. Valve.
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This step tests the PC Sol. Valve and the Automatic Transmission Wiring Harness Assembly for incorrect resistance.
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This step tests the PC Sol. Valve and the internal wiring harness for a short to ground.
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When performing this step refer to Product Service Bulletin #9474L80E-07 for PC Sol. Valve Application.
-
This step tests the entire PC Sol. Valve circuit for proper resistance.
-
This step tests for a short to ground in circuits 1228 and 1229 of the engine harness.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Important:: Before clearing the DTC's, record the Current and History DTC's information for reference. The Clear Info function will erase the stored Current and History DTC from the TCM. Is the PC Act. Current reading always within the specified value of the PC Ref. Current? | 0.16 | Go to Diagnostic Aids | ||
Is the resistance within the specified value? | 3-7ohms | |||
4 |
Is the resistance within the specified range? | 3-7ohms | ||
5 | Replace the Automatic Transmission Wiring Harness Assembly. Refer to Interior Wiring Harness Replacement, in On-Vehicle Service. Is the replacement complete? | -- | -- | |
Measure the resistance from terminal C in the J 39775 Jumper Harness to the transmission case. Is the resistance less than the specified value? | 9ohms | |||
7 |
Did you find the condition? | -- | ||
|
Important:: Refer to test description Step 8 for information on component replacement. Replace the PC Sol. Valve. Refer to Pressure Regulator Replacement . Is the replacement complete? | -- | -- | ||
Is the resistance within the specified range? | 3-7ohms | |||
Measure the resistance between terminal C 1 - D 16 and a good ground. Is the resistance greater than the specified value? | 7ohms | |||
11 | Is the resistance in Step 9 greater than the specified value? | 7ohms | ||
12 |
Did you find and repair the open condition? | -- | ||
13 |
Did you find and repair a shorted condition? | -- | -- | |
14 | Inspect circuit 1228 and circuit 1229 for a short to ground. Refer to General Electrical Diagnosis . Did you find and repair the shorted to ground condition? | -- | -- | |
15 | Replace the TCM. Refer to DTC 51 PROM Error TCM/PROM Replacement. Is the replacement complete? | -- | -- | |
16 | In order to verify your repair, perform the following procedure:
Is the PC Sol. Duty Cycle within the specified range? | 2 - 95% | System OK | Begin the Diagnosis again |
