Circuit Description
The TCC PWM Solenoid Valve controls the fluid acting on the converter clutch valve, which then controls the application and release of the TCC. The solenoid attaches to the control valve body within the transmission. Circuit 1339 supplies ignition voltage directly to the solenoid. The PCM controls the solenoid by providing a ground path on circuit 418. Current flows through the solenoid coil according to the duty cycle (percentage of ON and OFF time). The TCC PWM Solenoid Valve provides a smooth engagement of the torque converter clutch by operating during a duty cycle percent of ON time.
DTC P1860 detects a continuous open or a short to ground in the TCC PWM circuit or the TCC PWM Solenoid Valve. DTC P1860 is a type A DTC.
Conditions for Setting the DTC
| • | No system voltage DTC P0560 |
| • | No 2-3 shift solenoid DTCs P0756 or P0758 |
| • | No 1-2 shift solenoid DTCs P0751 or P0753 |
| • | The ignition is ON. |
| • | First gear commanded |
| • | The PCM commands the solenoid to 0% and the voltage remains high (B+). |
| • | All conditions met for 5 seconds |
Runs only during intrusive test:
| • | The TCC is at 100% duty cycle for 0.1 second. |
| • | The TCC is at 0% duty cycle for 5 seconds. |
| • | Once per key cycle |
Action Taken When the DTC Sets
| • | Inhibit TCC engagement |
| • | Inhibit 4th gear if in hot mode |
| • | The freeze shift adapts from being updated. |
| • | Maximum line pressure |
| • | The PCM illuminates the Malfunction Indicator Lamp (MIL). |
Conditions for Clearing the DTC
| • | The PCM turns OFF the MIL after three consecutive ignition cycles without a failure reported. |
| • | A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported. |
| • | The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM. |
Diagnostic Aids
| • | Inspect the wiring for any poor electrical connections at the PCM. Inspect the wiring at the transmission 20-way connector. Look 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 condition, massage the wiring harness while watching the test equipment for a change. |
Test Description
The numbers below refer to the step numbers on the diagnostic chart.
-
This Step verifies that the solenoid receives current.
-
This Step verifies the ability of the PCM and the wiring to control the ground circuit.
-
This Step measures the resistance of the TCC PWM Solenoid Valve and the Automatic Transmission wiring harness.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check , Section 6E3 | |||||||
2 |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and the Failure Records for reference. The Clear Info function will erase the data. Is the fuse open? | -- | ||||||||
3 | Inspect circuit 1339, the solenoid, and the Automatic Transmission wiring harness for a short to ground. Refer to Electrical Diagnosis, Section 8A. Did you find and correct a problem? | -- | -- | |||||||
Does the test lamp illuminate? | -- | |||||||||
5 | Repair the open or short to ground in the ignition feed circuit 1339 to the TCC PWM Solenoid Valve. Refer to Electrical Diagnosis, Section 8A. Is the repair complete? | -- | -- | |||||||
Does the test lamp illuminate when you command the TCC PWM Solenoid Valve ON, and turn OFF when you command the valve OFF? | -- | |||||||||
7 |
Refer to Electrical Diagnosis, Section 8A. Did you find and correct a problem? | -- | ||||||||
Is the resistance within the specified range? | 10-15ohms | |||||||||
9 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6 Is the replacement complete? | -- | -- | |||||||
10 |
Is the resistance within the specified range? | 10-15ohms | ||||||||
11 |
Are both readings greater than the specified value? | 250ohms | Go to Diagnostic Aids | |||||||
12 |
Refer to Electrical Diagnosis, Section 8A. Did you find and repair a problem? | -- | -- | |||||||
13 |
Are both readings greater than the specified value? | 250ohms | ||||||||
14 |
Refer to Electrical Diagnosis, Section 8A. Was a problem found and corrected? | -- | -- | |||||||
15 | Replace the TCC PWM Solenoid Valve. Refer to Valve Body. Is the replacement complete? | -- | -- | |||||||
16 |
Has the test run and passed? | -- | System OK |
