Circuit Description
Ignition voltage is provided to the Torque Converter Clutch Pulse Width Modulation Solenoid Valve (TCC PWM Sol. Valve). The Powertrain Control Module (PCM) controls the ON and OFF time of the solenoid by providing a ground through the Output Driver Module (ODM) B. The PCM uses a PWM duty cycle, in order to control application and release of the TCC. When the solenoid is commanded OFF, the PCM senses high volts. When the solenoid is commanded ON, the PCM senses low volts.
DTC P1860 sets anytime the received voltage is outside of the calibration limits. DTC P1860 is a type A DTC .
Conditions for Setting the DTC
| • | The system voltage is 9-16 volts. |
| • | The engine speed is greater than 500 RPM for 5 seconds, and not in fuel shut off. |
| • | The ignition is ON. |
| • | The PCM detects a low circuit voltage when the PWM duty cycle is greater than 90%. |
| • | The PCM detects a high circuit voltage when the PWM duty cycle is less than 10%. |
| • | All conditions are met for 5 seconds. |
Action Taken When the DTC Sets
| • | The PCM illuminates the Malfunction Indicator Lamp (MIL). |
| • | The PCM inhibits TCC operation. |
| • | The PCM inhibits 4th gear if the transmission is in Hot Mode |
| • | The PCM disables shift adapts. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the MIL after three consecutive trips 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 at the PCM, the transmission 20-way connector, the 2-way TCC 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. |
| • | Ensure that the transmission fluid is at the proper level. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step isolates the engine harness from the transmission harness. Use a test lamp in order to verify the circuitry.
-
This step verifies that circuit 418 is not open or shorted to power.
-
This step verifies that the TCC PWM solenoid is not shorted across its windings or increased its resistance.
-
Because of the harsh conditions inside the transmission, repairing the Automatic Transmission Wiring Harness is not acceptable. You must replace 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 in Engine Controls | |||||||||||||||
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. Are DTCs P0753 and P0758 set? | -- | ||||||||||||||||
3 |
Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct a condition? | -- | ||||||||||||||||
4 | Repair the short to ground in circuits 1039/839. Refer to Wiring Repairs in Wiring Systems. Did you find and correct a condition? | -- | -- | |||||||||||||||
5 | Repair the open in circuits 1039/839. Refer to Wiring Repairs in Wiring Systems. Did you find and correct a condition? | -- | -- | |||||||||||||||
Is the test lamp ON? | -- | |||||||||||||||||
7 | Inspect circuit 418 (BRN) of the engine harness for a short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct a condition? | -- | ||||||||||||||||
Important: When the TCC PWM solenoid is ON, the test lamp will be brilliant. When the TCC PWM solenoid is OFF, the test lamp will pulsate. Does the solenoid cycle ON and OFF as commanded? | -- | |||||||||||||||||
9 | Inspect circuit 418 (BRN) of the engine harness for an open or a short to power. Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct a condition? | -- | ||||||||||||||||
Refer to the Connector End View . Is the measured resistance within the specified range? | 10-12 ohms at 20°C (68°F) 13-15 ohms at 88°C (190°F) | |||||||||||||||||
11 | Is the resistance greater than the specified value? | 100 ohms | ||||||||||||||||
12 |
Refer to General Electrical Diagnosis in Wiring Systems. Did you find a condition? | -- | ||||||||||||||||
13 | Connect the DMM from terminal T of the jumper harness to ground. Is the measured resistance less than the specified value? | 100 ohms | ||||||||||||||||
14 | Inspect automatic transmission wiring harness circuit 418 (TAN) for a short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Did you find a condition? | -- | -- | |||||||||||||||
15 | Replace the TCC PWM Sol. Valve. Refer to Torque Converter Clutch Pulse Width Modulation Solenoid Replacement . Is the replacement complete? | -- | -- | |||||||||||||||
16 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | -- | |||||||||||||||
Replace the Automatic Transmission Wiring Harness. Refer to Solenoids and Wiring Harness Replacement . Is the replacement complete? | -- | -- | ||||||||||||||||
18 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
