Test Description Pontiac Montana I

Test Description

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

Scheme 316

1. This step determines if the Scan Tool is receiving power through the DLC connector.
2. The MIL should illuminate whenever the ignition is ON and the engine is not running.
3. This step determines if the PCM is transmitting class 2 serial data to the DLC and that the Class 2 data circuit is not open or shorted.
4. This step determines if a DTC is current or stored in history.

Scheme 317

Scheme 318

Scheme 319

Scheme 320

Scheme 321

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

Scheme 322

1. 2. This step ensures that the transmission fluid is at the proper level. A low fluid level may cause an overtemperature condition.

Scheme 323

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

1. 3. This step tests the ability of the VSS to produce an AC voltage. This step also verifies the integrity of the wiring to the PCM.
2. 4. This step tests the VSS circuit for correct resistance.

Scheme 324

Scheme 325

Scheme 326

Scheme 327

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

1. 3. This step tests the ability of the VSS to produce an AC voltage. This step also verifies the integrity of the wiring to the PCM.
2. 4. This step tests the VSS circuit for correct resistance.

Scheme 328

Scheme 329

Scheme 330

Scheme 331

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

Scheme 332

Scheme 333

1. 3. This step attempts to repeat the condition that set the DTC.
2. 5. This step attempts to repeat the condition in the engine wiring harness.
3. 6. This step determines if a condition exists with the PCM or TFT sensor.

Scheme 334

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

Scheme 335

Scheme 336

1. 2. A value below 0.2 volts indicates the fault is present. A value above 0.2 volts indicates the fault is intermittent.
2. 3. A value greater than 4.9 volts indicates the fault is in the transmission side.
3. 5. For resistance at other temperatures (Scheme 264)
4. 6. A value less than 10 K Q indicates a short to ground in the harness or sensor. A value greater than 10 K Q indicates the condition is intermittent.
5. 7. A value less than 10 K Q indicates a short together between the TFT signal circuit and the ground circuits.

Scheme 337

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

Scheme 338

Scheme 339

1. 2. A value above 4.9 volts indicates the fault is present. A value below 4.9 volts indicates the fault is intermittent.
2. 3. A value of 4.9-5.0 volts indicates the PCM and engine side of the wiring are good.
3. 6. A short to voltage greater than 5 volts would cause the TFT sensor to open.
4. 9. A short to the TFT sensor signal circuit and any other circuit in the transmission harness could cause the TFT sensor to open.

Scheme 340

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

Scheme 341

Scheme 342

1. 2. This step checks if the PCM receives a signal from the AT ISS sensor.
2. 3. A Yes answer indicates that the transmission side of the circuit is functioning properly.
3. 4. Although the resistance is within specification in Step 3, there may be a short to ground or a short to power condition.
4. 8. This step begins the transmission harness diagnosis.

Scheme 343

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

Scheme 344

Scheme 345

1. 2. This step checks if the PCM receives a signal from the AT ISS sensor.
2. 3. A Yes answer indicates that the transmission side of the circuit is functioning properly.
3. 5. Although the resistance is within specification in Step 3, there may be a short to ground or a short to power condition.
4. 8. This step begins the transmission harness diagnosis.

Scheme 346

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

Scheme 347

Scheme 348

1. 6. This step isolates the fault between the TCC brake switch and the harness.

Scheme 349

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

1. 3. If the Scan Tool display indicated Closed in Step 2, and Open when the switch is disconnected, the switch is stuck Closed.

Scheme 350

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

Scheme 351

Scheme 352

1. 3. This step tests for low fluid level, which may cause slipping and result in an undefined gear ratio.
2. 4. This step verifies that the correct gear ratios occur for commanded gears.
3. 5. This step tests for low line pressure.

Scheme 353

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

Scheme 354

Scheme 355

1. 5. This step verifies that the TCC engages when commanded ON by the Scan Tool.

Scheme 356

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

1. 2. A Yes answer indicates that the TCC is functioning properly.
2. 4. With the 20-way connector disconnected, the PCM should interpret the open circuit as TCC release pressure present.
3. 5. The TCC release switch is a normally closed switch and must be disconnected to properly test for a short to ground condition. An open condition in the TCC release circuit or switch would set DTC P1887. Open circuits are not diagnosed in DTC P0742.
4. 8. This step tests for a mechanical or hydraulic condition that would cause the TCC to be stuck ON.

Scheme 357

Scheme 358

Scheme 359

Scheme 360

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

Scheme 361

1. 2. This step verifies that the fault is present
2. 3. This step tests the transmission wiring harness and the PC solenoid valve for correct resistance.
3. 9. This step begins diagnosis of the engine side of the circuit.

Scheme 362

Scheme 363

Scheme 364

Important: Do not drive the vehicle for an extended period of time because additional internal damage may occur.

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

Scheme 365

1. 3. This step confirms that the PCM commanded all the shifts, but all the shifts did not occur.

Scheme 366

Important: Do not drive the vehicle for an extended period of time because additional internal damage may occur.

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

Scheme 367

1. 3. This step confirms that the PCM commanded all the shifts, but all the shifts did not occur.

Scheme 368

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

Scheme 369

Scheme 370

Scheme 371

1. 2. A short to ground in the power feed circuit to the solenoid ahead of the splice would open the fuse and set DTCs for other solenoids on the same circuit. An open in the same circuit would not open the fuse but, would set the other DTCs.

Scheme 372

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

1. 3. This step confirms that the PCM commanded all the shifts, but all the shifts did not occur.

Scheme 373

Scheme 374

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

Important: Do not drive the vehicle for an extended period of time, as additional internal damage may occur.

1. 3. This step confirms that the PCM commanded all the shifts, but all the shifts did not occur.

Scheme 375

Scheme 376

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

Scheme 377

Scheme 378

Scheme 379

1. 2. A short to ground in the power feed circuit to the solenoid ahead of the splice would open the fuse and set DTCs for other solenoids on the same circuit. An open in the same circuit would not open the fuse but, would set the other DTCs.

Scheme 380

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

Scheme 381

Scheme 382

Scheme 383

1. 3. This step tests the indicated range signal to the manual valve range actually selected.
2. 6. This step tests for correct voltage from the PCM to the transmission 20-way connector.
3. 7. This step tests for a short together between signal circuit A and signal circuits B or C.

Scheme 384

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

Scheme 385

Scheme 386

Scheme 387

1. 7. This step inspects components that may cause low line pressure.
2. 9. This step inspects or repairs components that may cause a maximum adapt and long 1-2 upshift.
3. 11. This step inspects or repairs components that may cause a maximum adapt and long 2-3 upshift.
4. 13. This step inspects or repairs components that may cause a maximum adapt and long 3-4 upshift.

Scheme 388

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

Scheme 389

1. 2. This step inspects the Failure Records for DTC P1814 occurrences.
2. 4. This step replaces the fluid and the filter. If DTC P1814 occurs more than once in the Failure Records, severe TCC damage may have occurred.