Circuit Description
The torque converter clutch pulse width modulated (TCC PWM) solenoid valve is a normally-closed solenoid used to control the apply and release of the converter clutch. The PCM operates the solenoid with a negative duty cycle. When vehicle operating conditions are appropriate to apply the TCC, the PCM immediately increases the duty cycle to approximately 42 percent. The PCM then ramps the duty cycle to approximately 90 percent to achieve full TCC apply pressure. When the solenoid is commanded OFF, the PCM senses high voltage. When the solenoid is commanded ON, the PCM senses low voltage.
When the PCM detects a continuous open, short to ground or short to voltage in the TCC PWM solenoid valve circuit, then DTC P1860 sets. DTC P1860 is a type A DTC .
Conditions for Running the DTC
| • | The system voltage is 8-18 volts. |
| • | The engine run time is greater than 5 seconds. |
| • | The engine is not in fuel cut off. |
| • | The TCC PWM solenoid valve duty cycle is less than 10 percent, or greater than 90 percent. |
Conditions for Setting the DTC
The PCM detects an open, short to ground or a short to voltage on the TCC PWM solenoid valve circuit for 4.3 seconds.
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL). |
| • | The PCM inhibits TCC engagement. |
| • | The PCM freezes transmission adapt functions. |
| • | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records. |
| • | The PCM stores DTC P1860 in PCM history. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes. |
| • | A scan tool can clear the MIL/DTC. |
| • | The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring. |
| • | The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM. |
Diagnostic Aids
Ensure the wiring harness is not stretched too tightly or other components are pressing on the connector body. Also, inspect for proper clearance to any other components and wiring. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the PCM and the wiring to the AT inline 20-way connector.
-
This step tests the control circuit for a short to voltage.
-
This step tests the circuit for correct resistance.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls | ||||||
2 |
Important: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the PCM. Is DTC P0753 or P0758 also set? | -- | Go to Step 3 | Go to Step 8 | ||||||
3 |
Refer to Wiring Repairs in Wiring Systems. Did you find the condition? | -- | Go to Step 4 | Go to Step 6 | ||||||
4 |
Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution. Test the ignition 1 voltage circuit (CKT 1039) of the TCC PWM solenoid valve for a short to ground between the underhood junction block and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 25 | Go to Step 5 | ||||||
5 |
Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution. Test the ignition 1 voltage circuit (CKT 839) of the TCC PWM solenoid valve for a short to ground between the AT inline 20-way connector and the TCC PWM solenoid valve. Refer to Circuit Testing in Wiring Systems. Did you find the condition? | -- | Go to Step 22 | -- | ||||||
6 | Test the ignition 1 voltage circuit (CKT 1039) of the TCC PWM solenoid valve for an open between the underhood junction block and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 25 | Go to Step 7 | ||||||
7 | Test the ignition 1 voltage circuit (CKT 839) of the TCC PWM solenoid valve for an open between the AT inline 20-way connector and the TCC PWM solenoid valve. Refer to Circuit Testing in Wiring Systems. Did you find the condition? | -- | Go to Step 22 | -- | ||||||
8 |
Refer to Automatic Transmission Inline Harness Connector End View . Is the test lamp ON? | -- | Go to Step 9 | Go to Step 11 | ||||||
9 |
Is the test lamp ON? | -- | Go to Step 10 | Go to Step 24 | ||||||
10 | Test the control circuit (CKT 418) of the TCC PWM solenoid valve for a short to ground between the PCM connector C2 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 25 | -- | ||||||
Using the scan tool, cycle the TCC PWM solenoid valve ON and OFF three times. Does the test lamp cycle ON and OFF as commanded? | -- | Go to Step 16 | Go to Step 12 | |||||||
12 | Is the test lamp always OFF? | -- | Go to Step 13 | -- | ||||||
13 | Test the control circuit (CKT 418) of the TCC PWM solenoid valve for an open between the PCM connector C2 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 25 | Go to Step 14 | ||||||
Connect a test lamp from terminal T of the J 44152 to ground. Refer to Automatic Transmission Inline Harness Connector End View . Is the test lamp ON? | -- | Go to Step 15 | Go to Step 24 | |||||||
15 | Test the control circuit (CKT 418) of the TCC PWM solenoid valve for a short to voltage between the PCM connector C2 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 25 | -- | ||||||
Refer to Automatic Transmission Inline Harness Connector End View . Is the resistance within the specified range? | 10-15 ohms | Go to Step 19 | Go to Step 17 | |||||||
17 | Is the resistance greater than the specified value? | 15 ohms | Go to Step 18 | Go to Step 19 | ||||||
18 |
Refer to Circuit Testing in Wiring Systems. Did you find a condition? | -- | Go to Step 22 | Go to Step 23 | ||||||
19 | Measure the resistance from terminal T of the J 44152 to ground. Refer to Automatic Transmission Inline Harness Connector End View . Is the resistance less than the specified value? | 1,000 ohms | Go to Step 20 | Go to Step 21 | ||||||
20 | Test the control circuit (CKT 418) of the TCC PWM solenoid valve for a short to ground between the AT inline 20-way connector and the TCC PWM solenoid valve. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find a condition? | -- | Go to Step 22 | -- | ||||||
21 | Measure the resistance between terminal T and all other terminals, except terminals A, B and E, of the J 44152 . Refer to Automatic Transmission Inline Harness Connector End View . Is the resistance between terminal T and any other terminal, except terminals A, B and E, less than the specified value? | 1,000 ohms | Go to Step 22 | Go to Step 23 | ||||||
22 | Replace the automatic transmission wiring harness. Refer to Transmission Overhaul in Transmission Unit Repair Manual. Did you complete the replacement? | -- | Go to Step 25 | -- | ||||||
23 | Replace the TCC PWM solenoid valve. Refer to Control and Shift Solenoids Replacement. Did you complete the replacement? | -- | Go to Step 25 | -- | ||||||
24 | Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls. Did you complete the replacement? | -- | Go to Step 25 | -- | ||||||
25 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK | Go to Step 1 |
