DTC P1860 TCC PWM Solenoid Circuit Electrical 6.5L Diesel
Circuit Description
The TCC PWM Solenoid Valve controls fluid acting on the converter clutch valve, which then controls TCC apply and release. The TCC PWM Sol. Valve attaches to the control valve body within the transmission. Ignition voltage goes directly to the TCC PWM Sol. Valve. The PCM controls the TCC PWM Sol. Valve by providing a ground path on circuit 418. The current flows through the TCC PWM Sol. Valve coil according to the duty cycle (percentage of ON and OFF time). The TCC PWM Sol. Valve provides a smooth engagement of the torque converter clutch by operating on a duty cycle percent of ON time.
When the PCM detects a continuous open or short to ground in the TCC PWM Sol. Valve circuit or the TCC PWM Sol. Valve, then DTC P1860 sets. DTC P1860 is a type A DTC.
Conditions for Setting the DTC
| • | No system voltage DTC P0560. |
| • | The ignition is ON. |
| • | No shift solenoid DTCs P0751, P0753, P0756, and P0758. |
| • | The PCM commands the solenoid to 0% and the voltage remains low (zero volts). |
| • | The PCM commands the solenoid to 100% and the voltage remains high. |
| • | All conditions are met for 5 seconds. |
Action Taken When the DTC Sets
| • | The PCM inhibits TCC engagement. |
| • | The PCM inhibits 4th gear if in hot mode. |
| • | 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 poor electrical connections at the PCM Inspect the wiring for poor electrical connections 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. |
| • | First diagnose and clear any engine DTCs or APP Sensor codes that are present. Then inspect for any transmission DTCs that may have reset. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for voltage to the TCC PWM Sol. Valve.
-
This step tests the ability of the PCM and wiring to control the ground circuit.
-
This step tests the resistance of the TCC PWM Sol. Valve and the internal wiring harness.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
2 |
Important: Before clearing the DTCs, 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 fuse open? | -- | ||||||||
3 | Inspect circuit 1020, the TCC PWM Sol. Valve and the internal wiring harness for a short to ground. Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | -- | -- | |||||||
Is the test lamp ON? | -- | |||||||||
5 | Repair the open or short to ground located in ignition voltage feed circuit 1020 to the TCC PWM Sol. Valve. Refer to Electrical Diagnosis, Section 8. Is the repair complete? | -- | -- | |||||||
Does the test lamp turn ON when you command the TCC PWM Sol. Valve ON, and does the lamp turn OFF when you command the TCC PWM Sol. Valve OFF? | -- | |||||||||
7 | Inspect and repair circuit 418 for an open or short to ground. Refer to Electrical Diagnosis, Section 8. Did you find a problem? | -- | ||||||||
Is the resistance within the specified values? | 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 values? | 10-15ohms | ||||||||
11 |
Are both readings greater than the specified value? | 250ohms | Go to Diagnostic Aids | |||||||
12 | Inspect and repair the internal wiring harness for an open circuit. Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | -- | -- | |||||||
13 |
Are both readings greater than the specified value? | 250ohms | ||||||||
14 | Inspect and repair the internal wiring harness for a short to ground. Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | -- | -- | |||||||
15 | Replace the TCC PWM Sol. Valve. Refer to 4L80-E On-vehicle Service. Is the replacement Complete? | -- | -- | |||||||
16 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
DTC P1860 TCC PWM Solenoid Circuit Electrical 4.3L, 5.7L, and 7.4L Gas
Circuit Description
The TCC PWM Solenoid Valve controls fluid acting on the converter clutch valve, which then controls TCC apply and release. The TCC PWM Sol. Valve attaches to the control valve body within the transmission. Ignition voltage goes directly to the TCC PWM Sol. Valve. The VCM controls the TCC PWM Sol. Valve by providing a ground path on circuit 418. The current flows through the TCC PWM Sol. Valve coil according to the duty cycle (percentage of ON time). The TCC PWM Sol. Valve provides a smooth engagement of the torque converter clutch by operating on a duty cycle percent of ON time.
When the VCM detects a continuous open or short in the TCC PWM Sol. Valve circuit or the TCC PWM Sol. Valve, then DTC P1860 sets. DTC P1860 is a type D DTC. For California emission vehicles DTC P1860 is a type A DTC.
Conditions for Setting the DTC
| • | No system voltage DTC P0560. |
| • | The ignition is ON. |
| • | No shift solenoid DTCs P0751, P0753, P0756, or P0758. |
| • | The VCM commands the solenoid to 0% and the voltage remains low (zero volts). |
| • | The brake switch is OFF. |
| • | All conditions are met for 5 seconds. |
Action Taken When the DTC Sets
| • | The VCM inhibits TCC engagement. |
| • | The VCM inhibits 4th gear. |
| • | The VCM freezes shift adapts from being updated. |
| • | The VCM illuminates the Malfunction Indicator Lamp. |
Conditions for Clearing the DTC
| • | For California emissions vehicles, the VCM turns OFF the MIL after three consecutive ignition cycles without a failure reported. |
| • | A scan tool can clear the DTC from the VCM history. The VCM clears the DTC from the VCM history if the vehicle completes 40 warm-up cycles without a failure reported. |
| • | The VCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the VCM. |
Diagnostic Aids
| • | Inspect the wiring for poor electrical connections at the VCM. Inspect the wiring for poor electrical connections 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. |
| • | First diagnose and clear any engine DTCs or TP Sensor codes that are present. Then inspect for any transmission DTCs that may have reset. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for voltage to the TCC PWM Sol. Valve.
-
This step tests the ability of the VCM and wiring to control the ground circuit.
-
This step tests the resistance of the TCC PWM Sol. Valve and the internal 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 (4.3L) or Powertrain On Board Diagnostic (OBD) System Check (5.7L and 7.4L) | |||||||
2 |
Important: Before clearing the DTCs, 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 fuse open? | -- | ||||||||
3 | Inspect circuit 1020, and the TCC PWM Sol. Valve. Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | - | -- | |||||||
Is the test lamp ON? | -- | |||||||||
5 | Repair the open or short to ground in ignition voltage feed circuit 1020 to the TCC PWM Sol. Valve. Refer to Electrical Diagnosis, Section 8. Is the repair complete? | -- | -- | |||||||
Does the test lamp turn ON when you command the TCC PWM Sol. Valve ON, and does the lamp turn OFF when you command the TCC PWM Sol. Valve OFF? | -- | |||||||||
7 |
Refer to Electrical Diagnosis, Section 8. Did you find a problem? | -- | ||||||||
Is the resistance within the specified values? | 10-15ohms | |||||||||
9 | Replace the VCM. Refer to VCM Replacement/Programming (Vehicle Control Module) , Section 6. Is the replacement complete? | -- | -- | |||||||
10 |
Is the resistance within the specified values? | 10-15ohms | ||||||||
11 |
Are both readings greater than the specified value? | 250ohms | Go to Diagnostic Aids | |||||||
12 |
Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | -- | -- | |||||||
13 |
Are both readings greater than the specified value? | 250ohms | ||||||||
14 |
Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | -- | -- | |||||||
15 | Replace the TCC PWM Sol. Valve. Refer to Torque Converter Clutch Pulse Width Modulation Solenoid Valve Replacement, in On-Vehicle Service. Is the replacement Complete? | -- | -- | |||||||
16 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
