For 1990-2009 cars

### Circuit Description

The Torque Converter Clutch Pulse Width Modulation Solenoid Valve (TCC PWM Sol Valve) controls the fluid acting on the converter clutch valve. The converter clutch valve controls the application and the release of the TCC. When you command the TCC PWM Sol Valve OFF, the Powertrain Control Module (PCM) receives high voltage. When you command the TCC PWM Sol Valve ON, the PCM receives low voltage.

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

• | System voltage is 10-16 volts.

• | The engine speed is more than 500 RPM.

• | Not in fuel shut off.

• | The PCM commands the solenoid to greater than 90%, and circuit 418 voltage remains low (0 volts).

• | The PCM commands the solenoid to less than 10%, and circuit 418 voltage remains high (B+).

All of the above conditions are met for 5 seconds.

### Action Taken When the DTC Sets

• | The PCM inhibits TCC operation.

• | The PCM inhibits 4th gear if the transmission is in the hot mode.

• | The PCM illuminates the Malfunction Indicator Lamp (MIL).

### Conditions for Clearing the MIL/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

1. Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring at the Automatic Transmission 7-way connector. Inspect the wiring at the 2-way TCC PWM Solenoid 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

2. When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.
3. Ensure that the transmission fluid is at the proper level.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step isolates the engine harness from the transmission harness.

2. This step verifies that circuit 418 is not open or shorted to power.

3. This step verifies that the TCC PWM solenoid is not shorted across its windings or increased its resistance.

#### DTC P1860 Torque Converter Clutch (PWM) Solenoid -- Electrical

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 |

1. Install the Scan Tool ®.
2. With the engine OFF, turn the ignition switch to the RUN position.

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.

3. Record the DTC Freeze Frame and Failure Records.
4. Select TCC PWM Open and TCC PWM Shorted on the scan tool.

Did either one read Yes?

--

Go to Step 3

Go to Diagnostic Aids

3 |

1. Turn the ignition switch OFF.
2. Disconnect the Automatic Transmission 7-way connector.
3. Install the J 38835 Transmission Electrical Jumper to the engine harness connector.
4. Connect a test lamp from terminal E to terminal C of the jumper using a J 35616-A Connector Test Adapter Kit.
5. With the engine OFF, turn the ignition ON.
6. Additional DTCs will set.

Is the test lamp OFF?

--

Go to Step 4

Go to Step 5

4 | Inspect circuit 418 for an open. Refer to Troubleshooting procedures, Section 8. Was a condition found and corrected? | -- | Go to Step 16 | Go to Step 15
5 |

1. Select A/T Outputs, TCC PWM Solenoid.
2. Cycle the TCC PWM solenoid ON and OFF three times.

Important: When the TCC PWM circuit is commanded ON, the test lamp will be OFF. When the TCC PWM circuit is commanded OFF, the test lamp will be ON.

Does the solenoid cycle ON and OFF as commanded?

--

Go to Step 8

Go to Step 6

6 | Inspect circuit 418 for a short to ground. Refer to Troubleshooting Procedures, Section 8. Was a condition found and corrected? | -- | Go to Step 16 | Go to Step 7
7 | Inspect circuit 418 for a short to power. Refer to Troubleshooting Procedures, Section 8. Was a condition found and corrected? | -- | Go to Step 16 | Go to Step 15
8 |

1. Turn the ignition switch OFF.
2. Disconnect the Transmission Jumper from the engine harness.
3. Connect the J 38835 Transmission Electrical Jumper to the Automatic Transmission 7-way connector.
4. Connect a J 39200 Digital Multimeter (DMM) from terminal E to terminal C of the jumper.

Is the measured resistance within the specified range?

10 ohms to 15 ohms

Go to Step 15

Go to Step 9

9 | Is the resistance greater than the specified value? | 100 ohms | Go to Step 10 | Go to Step 11
10 | Inspect the RED wire circuit 1339 for an open. Inspect the BLK wire circuit 418 for an open. Refer to Troubleshooting Procedures, Section 8. Was a condition found and corrected? | -- | Go to Step 16 | Go to Step 13
11 | Connect a J 39200 Digital Multimeter (DMM) from terminal C of the jumper to ground. Is the measured resistance less than the specified value? | 100 ohms | Go to Step 12 | Go to Step 13
12 | Inspect the BLK wire circuit 418 for a short to ground. Refer to Troubleshooting Procedures, Section 8. Was a condition found and corrected? | -- | Go to Step 16 | --
13 | Replace the TCC PWM Sol. Valve. Refer to Solenoids and Wiring Harness, Section 7. Is the replacement complete? | -- | Go to Step 16 | --
14 | Inspect PCM connector C1 for bent, damaged or backed out connector pins. Was a condition found and corrected? | -- | Go to Step 16 | Go to Step 15
15 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete? | -- | Go to Step 16 | --
16 | In order to verify your repair, perform the following procedure:

1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle under the following conditions:

• | The ignition switch is ON.

• | The engine speed is more than 500 RPM.

• | The vehicle is not in fuel shut off.

• | Drive the vehicle for a TCC ON cycle.

• | System voltage is 10-16 volts.

• | The PCM commands the solenoid to greater than 90%, and circuit 418 voltage increases to (B+).

• | The PCM commands the solenoid to less than 10%, and circuit 418 voltage decreases to 0 V.

• | All conditions are met for 5 seconds.

4. Select Specific DTC. Enter DTC P1860.

Has the test run and passed?

--

System OK

Begin the diagnosis again. Go to Step 1