Engine Controls - Self-Diagnostics - M45: Diagnosis Infiniti M45 II

ON-BOARD DIAGNOSTICS

ECM detects malfunctions related to engine sensors or actuators. OBD-II monitors emission related components and can store Diagnostic Trouble Codes (DTCs), 1st trip DTCs, freeze-frame data, 1st trip freeze-frame data and System Readiness Test (SRT) information. Using a scan tool, this data and DTC information can be retrieved to assist in diagnosing problems. The Malfunction Indicator Light (MIL) can be used for code retrieval and fuel feedback monitoring.

When a malfunction is detected for the 1st time, the 1st trip DTC and 1st trip freeze frame data are stored in ECM memory. However, in most instances, MIL will not be illuminated. If the same malfunction is detected on the next trip (under similar conditions), MIL will be illuminated and a DTC is stored (2nd trip detection logic). If a misfire or fuel system malfunction should occur during 1st trip, MIL may be illuminated or flash. DTC and freeze-frame information will be stored to aid in diagnostics by specifying operating conditions when DTC was set. Some 1st trip DTC freeze frame data is not viewable with Generic Scan Tool (GST). (Scheme 248)

Scheme 248

DTC & 1ST TRIP DTC

The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, the 1st trip DTC will not be displayed. If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory.

The MIL will not light up (two trip detection logic). If the same malfunction is not detected in the 2nd trip (meeting the required driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the 2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MIL lights up.

In other words, the DTC is stored in the ECM memory and the MIL lights up when the same malfunction occurs in 2 consecutive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or light up the MIL during the 1st trip, the DTC and 1st trip DTC are stored in the ECM memory.

Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in CLEARING DIAGNOSTIC TROUBLE CODES . For malfunctions in which 1st trip DTCs are displayed, see EMISSION-RELATED DIAGNOSTIC INFORMATION . These items are required by legal regulations to continuously monitor the system/component. In addition, the items monitored non-continuously are also displayed on CONSULT-II.

1st trip DTC is specified in Mode 7 of SAE J1979. 1st trip DTC detection occurs without lighting up the MIL and therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent the vehicle from being tested, for example during Inspection/Maintenance (I/M) tests. When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame data as specified in step 2 of TESTING PROCEDURE. Then perform appropriate DTC confirmation procedure or overall function check to try to duplicate the malfunction. If the malfunction is duplicated, the item requires repair.

How To Read DTC & 1st Trip DTC

DTC and 1st trip DTC can be read with CONSULT-II, Generic Scan Tool (GST) or by the number of blinks of the MIL in the Diagnostic Test Mode II. Examples: P0340, P1148, P1706, etc. These DTCs are prescribed by SAE J2012. (CONSULT-II also displays the malfunctioning component or system.)

DTC or 1st trip DTC of a malfunction is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-II. Time data indicates how many times the vehicle was driven after the last detection of a DTC. If the DTC is being detected currently, the time data will be "0". If a 1st trip DTC is stored in the ECM, the time data will be "[1t]". For a sample of CONSULT-II displays for DTC and 1st trip DTC (Scheme 249)

Scheme 249

DTC Inspection Priority

If some DTCs are displayed at the same time, perform inspections one by one based on priority, see MULTIPLE DTC PRIORITY IDENTIFICATION table.

MULTIPLE DTC PRIORITY IDENTIFICATION

Diagnostic Worksheet

There are many operating conditions that lead to the malfunction of engine components. A good grasp of such conditions can make trouble shooting faster and more accurate. In general, each customer feels differently about an incident. It is important to fully understand the symptoms or conditions for a customer complaint. Utilize a diagnostic worksheet like the one in (Scheme 250) in order to organize all the information for troubleshooting. Some examples of conditions that may cause the MIL to come on steady or blink and DTC to be detected are as follows

1. Vehicle ran out of fuel, which caused the engine to misfire.
2. Fuel filler cap was left off or incorrectly screwed on, allowing fuel to evaporate into the atmosphere.

Scheme 250

Using Scan Tool

For scan tool usage, see SCAN TOOL USAGE .

Diagnostic Test Mode II (Self-Diagnostic Results)

In this mode, DTCs and 1st trip DTCs are indicated by the number of MIL flashes. DTCs and 1st trip DTCs are displayed at the same time. If MIL does not illuminate when engine is running in diagnostic test mode I, all displayed items are 1st trip DTCs. If MIL is illuminated when engine is running in diagnostic test mode I, and only one DTC is indicated, it is a DTC. If 2 or more DTCs are indicated, they may be either DTCs or 1st trip DTCs.

A particular DTC can be identified by the number of 4 digit numeral flashes of MIL. The zero is indicated by 10 flashes. The length of time the 1000th digit numeral flashes on and off is 1.2 seconds consisting of an ON (0.6-second) OFF (0.6-second) cycle. The 100th digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle. A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later numeral appears on the display 1.3 seconds after the former numeral has disappeared. A change from one trouble code to another occurs at an interval of 1.8-second OFF. In this way, all the detected malfunctions are classified by their DTC numbers. (Scheme 251)

Scheme 251

Diagnostic Test Mode II (Front HO2S Monitor)

In this mode, MIL displays fuel mixture condition (lean or rich), as monitored by front HO2S. MIL is on when mixture is lean and off when mixture is rich. Therefore, a flashing MIL indicates closed loop fuel control and a MIL that remains on or off indicates open loop.

To check front HO2S function, start engine in diagnostic test mode II. See ENTERING DIAGNOSTIC TEST MODE II (FRONT HO2S MONITORING) . Warm engine to normal operating temperature. Run engine at 2000 RPM for 2 minutes. MIL should come on more than 5 times within 10 seconds with engine running at 2000 RPM under no load.

Entering Diagnostic Test Mode II (Self-Diagnostic Results Mode)

Note. Switching diagnostic test modes is impossible if accelerator pedal position sensor circuit has a malfunction. ECM always returns to diagnostic test mode I after ignition is turned off.

1. Ensure accelerator pedal is fully released. Turn ignition on and wait 3 seconds.
2. Repeat the following 5 times within 5 seconds. Fully depress accelerator pedal. Fully release accelerator pedal.
3. Wait 7 seconds. Fully depress accelerator pedal, and hold for about 10 seconds until MIL starts flashing.
4. Fully release accelerator pedal. ECM is now in diagnostic test mode II.

Entering Diagnostic Test Mode II (Front HO2S Monitoring)

1. Enter self-diagnostic results mode. See «ENTERING DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC RESULTS MODE)»(ref-159509-S00959244132003121500000).
2. Start engine. ECM has now entered front HO2S monitoring.
3. To switch from bank 1 to bank 2 or from bank 2 to bank 1, fully depress and release accelerator pedal quickly.
4. Ensure monitoring sensor has changed by flashing MIL as shown in illustration. (Scheme 252)

Scheme 252

CLEARING DIAGNOSTIC TROUBLE CODES

Note. The emission related diagnostic information in the ECM can be erased by selecting "ERASE" in the "SELFDIAG RESULTS" mode with CONSULT-II. If DTCs are displayed for both ECM and TCM, they need to be erased individually from the ECM and TCM. If the DTC is not for A/T related items, skip step No. 2.

Note. If the battery is disconnected, the emission-related diagnostic information will be lost after about 24 hours.

Using Generic Scan Tool

If ignition is on, turn ignition off and wait at least 10 seconds. Turn ignition on. Select MODE 4 or follow scan tool manufacturer's instructions.

SYSTEM READINESS TEST

Note. SRT procedure was written specifically for use with Nissan's CONSULT-II diagnostic scan tool. Generic scan tools can be used but may have limited functions.

TEST VALUE & TEST LIMIT (GST ONLY - NOT APPLICABLE TO CONSULT-II)

The following is the information specified in Mode 6 of SAE J1979. The test value is a parameter used to determine whether a system/circuit diagnostic test is "OK" or "NG" while being monitored by the ECM during self-diagnosis. The test limit is a reference value which is specified as the maximum or minimum value and is compared with the test value being monitored. Items for which this data (test value and test limit) is displayed are the same as SRT code items (30 test items). This data (test value and test limit) is specified by Test ID (TID) and Component ID (CID) and can be displayed on the GST screen. (Scheme 253)

Scheme 253

SCAN TOOL USAGE

Note. For testing related to ECM power and ground circuits, see POWER & GROUND CIRCUITS (M45) under ENGINE CONTROL MODULE (ECM) under COMPUTERIZED ENGINE CONTROLS in SYSTEM & COMPONENT TESTING article.

Entering Diagnostic Test Modes

Turn ignition off. Connect scan tool to DLC. (Scheme 254) Turn ignition on. Press START on scan tool. Press ENGINE. Select one of the following diagnostic test modes

1. WORK SUPPORT This mode enables a technician to adjust some devices faster and more accurately by following indications on CONSULT-II unit. See «WORK SUPPORT MODE»(ref-159509-S23744505092003121500000) .
2. SELF-DIAGNOSTIC RESULTS Self-diagnostic results such as 1st trip DTC, DTCs, 1st trip freeze frame data or freeze frame data can be read and erased quickly. See «SELF-DIAGNOSTIC RESULTS MODE»(ref-159509-S15259957082003121500000) . Diagnostic trouble codes, 1st trip diagnostic trouble codes, freeze frame data, 1st trip freeze frame data, System Readiness Test (SRT) codes, test values and others are cleared when the ECM memory is erased.
3. DATA MONITOR Input/output data in ECM can be read. See «DATA MONITOR MODE»(ref-159509-S38144509332003121500000) .
4. DATA MONITOR (SPEC) Input/output specification of basic fuel schedule, AFM, A/F feedback control value and other data monitor items can be read. See «DATA MONITOR (SPEC) MODE»(ref-159509-S36503665712003121500000) .
5. ACTIVE TEST Diagnostic test mode in which CONSULT-II drives some actuators apart from ECMs and also shifts some parameters in a specified range. See «ACTIVE TEST MODE»(ref-159509-S22900347392003121500000) .
6. DTC & SRT CONFIRMATION The status of system monitoring tests and self-diagnosis status/result can be confirmed.
7. FUNCTION TEST This mode is used to inform customers when their vehicle condition requires periodic maintenance.
8. ECM PART NUMBER ECM part number can be read.

Scheme 254

Active Test Mode

For ACTIVE TEST mode descriptions (Scheme 255)

Scheme 255

GENERIC SCAN TOOL

An OBD-II scan tool complying with SAE J1978 has the following functions. For further information, see the appropriate operation manual supplied by scan tool manufacturer.

Mode 1: Readiness Test

This mode gains access to current emission-related data values, including analog inputs and outputs, digital inputs and outputs, and system status information.

Mode 3: Diagnostic Trouble Codes (DTCs)

This mode gains access to emission-related powertrain DTCs stored by ECM. For DTC definitions, see DIAGNOSTIC TROUBLE CODE DEFINITIONS .

Mode 8: EVAP System Testing

This mode can close EVAP system with ignition on (engine off). The following components can be opened or closed

1. EVAP canister vent control can be opened.
2. Vacuum cut valve by-pass valve can be closed.

During the following conditions, mode 8 cannot function

1. Low ambient temperature or low fuel temperature.
2. Low battery voltage.
3. Engine running or ignition switch in the OFF position.
4. Too much pressure applied to EVAP system.

Testing Condition

1. Vehicle driven distance: More than 5,000 km (3,017 miles).
2. Barometric pressure: 14.25-15.12 psi (98.3-104.3 kPa).
3. Atmospheric temperature: 68-86°F (20-30°C).
4. Engine coolant temperature: 167-203°F (75-95°C).
5. Transmission warmed-up. After the engine is warmed up to normal operating temperature, drive vehicle until "FLUID TEMP SE" (A/T fluid temperature sensor signal) indicates more than 140°F (60°C).
6. Electrical load not applied. Rear window defogger switch, air conditioner switch, lighting switch are "OFF". Steering wheel is straight ahead.
7. Engine at idle.

Inspection Procedure

Note. Perform "DATA MONITOR (SPEC)" mode in maximum scale display.

1. Perform «M45»(ref-151800-S21856755622003081800000) under BASIC INSPECTION in ON-VEHICLE ADJUSTMENTS article.
2. Confirm that the previuos testing conditions indicated are met.
3. Select "B/FUEL SCHDL", "A/F ALPHA-B1", "A/F ALPHA-B2" and "MAS A/F SE-B1" in "DATA MONITOR (SPEC)" mode with CONSULT-II.
4. Ensure that monitor items are within the specification value. See «CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE»(ref-159509-S27355750382003123000000) in CONSULT-II.
5. If the monitored items are not within specification, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S11764404472003123000000) .

Diagnostic Procedure

For A/F alpha and B/FUEL schedule diagnostic procedures (Scheme 256)- (Scheme 258).

Scheme 256

Scheme 257

Scheme 258

1. Erase (1st trip) DTCs. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-159509-S16089186672003121500000) under SELF-DIAGNOSTIC SYSTEM.
2. Check ground terminals for corroding or loose connection. If okay, go to next step. If not okay, repair as necessary.
3. Inspect suspect circuit. If circuit is okay, go to next step. If circuit is not okay, repair as necessary.
4. Check connectors and terminals. If terminals and connectors are okay, system is okay at this time. If terminals and connectors are not okay, repair as necessary.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TROUBLE CODE DEFINITIONS

Scheme 259

Scheme 260

Scheme 261

Scheme 262

Scheme 263

Scheme 264

Scheme 265

Scheme 266

Scheme 267

Component Inspection

For intake valve timing control solenoid valve and position sensor component inspection (Scheme 268)

Scheme 268

On Board Diagnosis Logic

For on board diagnosis logic (Scheme 269)

Scheme 269

Fail-Safe Mode

For fail-safe mode (Scheme 270)

Scheme 270

DTC Confirmation Procedure For Malfunctions "A" & "B"

Note. If DTC confirmation procedure has been previously conducted, always turn ignition switch "OFF" and wait at least 10 seconds before conducting the next test. Before performing the DTC Confirmation Procedure For Malfunctions "A" & "B", confirm that battery voltage is between 10-16 volts at idle.

For DTC confirmation procedure for malfunctions "A" and "B" (Scheme 271)

Scheme 271

For diagnostic procedures (Scheme 272)- (Scheme 274).

Scheme 272

Scheme 273

Scheme 274

For on board diagnosis logic (Scheme 275)

Scheme 275

DTC Confirmation Procedure

For DTC confirmation procedure (Scheme 276)

Scheme 276

For diagnostic procedure (Scheme 277)and (Scheme 278).

Scheme 277

Scheme 278

For component inspection (Scheme 279)

Scheme 279

For on board diagnosis logic (Scheme 280)

Scheme 280

For DTC confirmation procedure (Scheme 281)

Scheme 281

For diagnostic procedure (Scheme 282)and (Scheme 283).

Scheme 282

Scheme 283

For component inspection (Scheme 284)

Scheme 284

For on board diagnosis logic (Scheme 285)

Scheme 285

DTC Confirmation Procedures For Malfunctions "A" & "B"

For DTC confirmation procedures for malfunctions "A" & "B" (Scheme 286)

Scheme 286

For diagnostic procedure (Scheme 287)- (Scheme 289).

Scheme 287

Scheme 288

Scheme 289

For component inspection (Scheme 290)

Scheme 290

For on board diagnosis logic (Scheme 291)

Scheme 291

For fail-safe mode (Scheme 292)

Scheme 292

For DTC confirmation procedure (Scheme 293)

Scheme 293

For diagnostic procedure (Scheme 294)- (Scheme 296).

Scheme 294

Scheme 295

Scheme 296

For component inspection, see COMPONENT INSPECTION under DTC P0101: MASS AIRFLOW SENSOR.

For on board diagnosis logic (Scheme 297)

Scheme 297

For DTC confirmation procedure (Scheme 298)

Scheme 298

For diagnostic procedure (Scheme 299)

Scheme 299

For component inspection (Scheme 300)

Scheme 300

For on board diagnosis logic (Scheme 301)

Scheme 301

For fail-safe mode (Scheme 302)

Scheme 302

For DTC confirmation procedure (Scheme 303)

Scheme 303

For diagnostic procedure (Scheme 304)and (Scheme 305).

Scheme 304

Scheme 305

For component inspection (Scheme 306)

Scheme 306

For on board diagnosis logic (Scheme 307)

Scheme 307

For fail-safe mode (Scheme 308)

Scheme 308

For DTC confirmation procedure (Scheme 309)

Scheme 309

For diagnostic procedure related to Throttle Position (TP) sensor (Scheme 310)- (Scheme 312).

Scheme 310

Scheme 311

Scheme 312

For component inspection (Scheme 313)

Scheme 313

For on board diagnosis logic (Scheme 314)

Scheme 314

For DTC confirmation procedure (Scheme 315)

Scheme 315

For diagnostic procedure (Scheme 316)

Scheme 316

For component inspection (Scheme 317)

Scheme 317

For component description (Scheme 318)

Scheme 318

For DTC confirmation procedure (Scheme 319)

Scheme 319

For diagnostic procedure, see DTC P0112 & P0113: INTAKE AIR TEMPERATURE SENSOR .

For component inspection, see DTC P0112 & P0113: INTAKE AIR TEMPERATURE SENSOR .

For on board diagnosis logic (Scheme 320)

Scheme 320

For DTC confirmation procedure (Scheme 321)

Scheme 321

For diagnostic procedure (Scheme 322)

Scheme 322

For component inspection (Scheme 323)

Scheme 323

For on board diagnosis logic (Scheme 324)

Scheme 324

For DTC confirmation procedure (Scheme 325)

Scheme 325

For diagnostic procedure (Scheme 326)and (Scheme 327).

Scheme 326

Scheme 327

For component inspection (Scheme 328)and (Scheme 329).

Scheme 328

Scheme 329

For on board diagnosis logic (Scheme 330)

Scheme 330

For DTC confirmation procedure (Scheme 331)

Scheme 331

For diagnostic procedures (Scheme 332)- (Scheme 336).

Scheme 332

Scheme 333

Scheme 334

Scheme 335

Scheme 336

For component inspection (Scheme 337)and (Scheme 338).

Scheme 337

Scheme 338

For component inspection (Scheme 339)

Scheme 339

For on board diagnosis logic (Scheme 340)

Scheme 340

For DTC confirmation procedure (Scheme 341)

Scheme 341

For diagnostic procedure (Scheme 342)and (Scheme 343).

Scheme 342

Scheme 343

For component inspection (Scheme 344)

Scheme 344

For on board diagnosis logic (Scheme 345)

Scheme 345

For DTC confirmation procedure (Scheme 346)

Scheme 346

For diagnostic procedures (Scheme 347)- (Scheme 350).

Scheme 347

Scheme 348

Scheme 349

Scheme 350

For component inspection (Scheme 351)- and (Scheme 352).

Scheme 351

Scheme 352

For on board diagnosis logic (Scheme 353)

Scheme 353

For DTC confirmation procedure (Scheme 354)

Scheme 354

For diagnostic procedures (Scheme 355)- (Scheme 358).

Scheme 355

Scheme 356

Scheme 357

Scheme 358

For component inspection (Scheme 359)and (Scheme 360).

Scheme 359

Scheme 360

DTC Confirmation Procedure (Using CONSULT-II)

1. Start engine and warm to normal operating temperature. Turn ignition off and wait at least 10 seconds. Turn ignition on. Select SELF-LEARNING CONT in WORK SUPPORT mode. Clear self-learning control coefficient by pressing CLEAR.
2. Select DATA MONITOR mode. Start engine and let it idle for at least 10 minutes. If 1st trip DTC P0171 or P0174 is detected, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S13095966802003121500000) . If 1st trip DTC P0171 or P0174 is not detected, go to next step.
3. If it is difficult to start engine, fuel injection system has a malfunction. Crank engine while depressing accelerator pedal. If engine starts, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S13095966802003121500000) . If engine does not start, visually check for intake and exhaust leaks.

DTC Confirmation Procedure (Using Generic Scan Tool)

1. Start engine and warm to normal operating temperature. Turn ignition off and wait at least 10 seconds. Disconnect MAF sensor harness connector. Start engine and let it idle for at least 5 seconds. Turn ignition off and reconnect MAF sensor harness connector.
2. Select MODE 3 with GST. Ensure DTC P0102 is detected. Select MODE 4 and erase 1st trip DTC. Start engine and let it idle for at least 10 minutes. Select MODE 7. If 1st trip DTC P0171 or P0174 is detected, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S13095966802003121500000) . If 1st trip DTC P0171 or P0174 is not detected, go to next step.
3. If it is difficult to start engine, fuel injection system has a malfunction. Attempt to start engine while depressing accelerator pedal. If engine starts, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S13095966802003121500000) . If engine does not start, visually check for intake and exhaust leaks.

For diagnostic procedures (Scheme 361)- (Scheme 364).

Scheme 361

Scheme 362

Scheme 363

Scheme 364

For on board diagnosis logic (Scheme 365)

Scheme 365

For DTC confirmation procedure (Scheme 366)

Scheme 366

For diagnostic procedures (Scheme 367)- (Scheme 370).

Scheme 367

Scheme 368

Scheme 369

Scheme 370

For on board diagnosis logic (Scheme 371)

Scheme 371

For DTC confirmation procedure (Scheme 372)

Scheme 372

For diagnostic procedure (Scheme 373)- (Scheme 374).

Scheme 373

Scheme 374

For component inspection (Scheme 375)

Scheme 375

For on board diagnosis logic (Scheme 376)

Scheme 376

For DTC confirmation procedure (Scheme 377)

Scheme 377

For fuel tank temperature sensor diagnostic procedure (Scheme 373)- (Scheme 374).

For fuel tank temperature sensor component inspection (Scheme 375)

For on board diagnosis logic (Scheme 378)

Scheme 378

For fail-safe mode (Scheme 379)

Scheme 379

For DTC confirmation procedure (Scheme 380)

Scheme 380

For diagnostic procedures (Scheme 381)and (Scheme 382).

Scheme 381

Scheme 382

For component inspection (Scheme 383)

Scheme 383

For DTC confirmation procedure (Scheme 384)

Scheme 384

1. Start engine and let it idle. Check for intake leaks. Stop engine and visually inspect exhaust system, 3-way catalyst and muffler for blockage. If a problem is found, repair as necessary. If no problems are found, go to next step.
2. If using CONSULT-II, go to next step. If using generic scan tool, go to step 4 .
3. Perform POWER BALANCE in ACTIVE TEST mode with CONSULT-II. If there is any cylinder which does not produce a momentary engine speed drop, go to step 5 . If all cylinders produce a momentary engine speed drop, go to step 8 .
4. Start engine and let it idle. Individually, disconnect fuel injector harness connectors. If there is any cylinder which does not produce a momentary engine speed drop, go to next step. If all cylinders produce a momentary engine speed drop, go to step 8 .
5. Listen to each fuel injector. If every injector clicks, go to next step. If any injector does not click, repair injector or circuit as necessary. See «FUEL SYSTEM»(ref-151810-S29003858602003010800000) in SYSTEM & COMPONENT TESTING article.
6. Turn ignition off. Disconnect spark plug wire from spark plug. Connect a known good spark plug to spark plug wire. Place end of spark plug against a suitable ground and crank engine. If spark is detected, go to next step. If no spark is detected, check ignition coil, power transistor and their related circuits.
7. Remove spark plugs. Inspect spark plugs for fouling or other damage. If problem is found, repair or replace spark plugs as necessary. If spark plugs are okay, go to next step.
8. Check compression. See «MECHANICAL INSPECTION»(ref-151802-S15020718502003010800000) under PRELIMINARY INSPECTION & ADJUSTMENTS in BASIC DIAGNOSTIC PROCEDURES article. See «COMPRESSION SPECIFICATIONS»(ref-159509-S42593953882003121500000) table. If compression is as specified, go to next step. If compression is not as specified, check pistons, piston rings, valves, valve seats and cylinder head gaskets. Repair as necessary.
9. Check fuel pressure. See «FUEL SYSTEM»(ref-151802-S39076091332003010800000) in BASIC DIAGNOSTIC PROCEDURES article. Fuel pressure should be about 34 psi (235 kPa) at idle. If fuel pressure is okay, go to next step. If fuel pressure is not okay, repair fuel system as necessary. See «FUEL SYSTEM»(ref-151810-S29003858602003010800000) in SYSTEM & COMPONENT TESTING article.
10. Check target idle speed and ignition timing. See «M45»(ref-151800-S21856755622003081800000) under BASIC INSPECTION in ON-VEHICLE ADJUSTMENTS article. If ignition timing and target idle speed are okay, go to next step. If ignition timing or target idle speed is not okay, repair or adjust as necessary. See «M45»(ref-151800-S21856755622003081800000) under BASIC INSPECTION in ON-VEHICLE ADJUSTMENTS article.
11. Start engine and warm to normal operating temperature. Check Heated Oxygen Sensor 1 (HO2S1) Bank 1/Bank 2. See «COMPONENT INSPECTION»(ref-159509-S18505273952004011500000) under DTC P0132 & P0152: HEATED OXYGEN SENSOR 1. If operation is as specified, go to step 12 . If operation is not as specified, replace appropriate HO2S.
12. Check Mass Airflow (MAF) sensor. With CONSULT-II, select DATA MONITOR. On generic scan tool, select MODE 1 and read Mass Airflow (MAF) signal. MAF reading should be 3.8-5.2 grams per second at idle and 16.0-21.5 grams per second at 2500 RPM. If MAF reading is as specified, go to step 14 . If MAF reading is not as specified, go to next step.
13. Check connectors for rusted terminals or loose connections in MAF sensor circuit or engine grounds. See «DTC P0102 & DTC P0103: MASS AIRFLOW SENSOR»(ref-159509-S01308148372004011300000) . Repair as necessary.
14. Check for possible causes of rough idle. See «ROUGH IDLE»(ref-151809-S16325409882003010800000) under SYMPTOMS in TROUBLE SHOOTING - NO CODES article. If a problem is found, repair as necessary. If a problem is not found, go to next step.
15. Some tests that were performed may cause a 1st trip DTC to set. Clear 1st trip DTC as necessary. Go to next step.
16. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-151809-S41696183142003010800000) in TROUBLE SHOOTING - NO CODES article.

COMPRESSION SPECIFICATIONS

For on board diagnosis logic (Scheme 385)

Scheme 385

For DTC confirmation procedure (Scheme 386)

Scheme 386

For diagnostic procedure (Scheme 387)and (Scheme 388).

Scheme 387

Scheme 388

For component inspection (Scheme 389)

Scheme 389

For on board diagnosis logic (Scheme 390)

Scheme 390

For DTC confirmation procedure (Scheme 391)

Scheme 391

For wiring diagrams and specification data for crankshaft position sensor (Scheme 392)and (Scheme 393).

Scheme 392

Scheme 393

For component inspection (Scheme 394)

Scheme 394

For on board diagnosis logic (Scheme 395)

Scheme 395

For DTC confirmation procedure (Scheme 396)

Scheme 396

For diagnostic procedure (Scheme 397)- (Scheme 399).

Scheme 397

Scheme 398

Scheme 399

For component inspection (Scheme 400)

Scheme 400

For on board diagnosis logic (Scheme 401)

Scheme 401

For DTC confirmation procedure (Scheme 402)

Scheme 402

For diagnostic procedure (Scheme 403)and (Scheme 404).

Scheme 403

Scheme 404

For on board diagnosis logic (Scheme 405)

Scheme 405

For DTC confirmation procedure (Scheme 406)

Scheme 406

Overall Function Test

For overall function test (Scheme 407)

Scheme 407

For diagnostic procedure (Scheme 408)- (Scheme 412).

Scheme 408

Scheme 409

Scheme 410

Scheme 411

Scheme 412

For on board diagnosis logic (Scheme 413)

Scheme 413

For DTC confirmation procedure (Scheme 414)and (Scheme 415).

Scheme 414

Scheme 415

Note. For views of evaporative emission line drawings (Scheme 411)and (Scheme 412).

For diagnostic procedure (Scheme 416)- (Scheme 421).

Scheme 416

Scheme 417

Scheme 418

Scheme 419

Scheme 420

Scheme 421

For component inspections (Scheme 422)(Scheme 423).

Scheme 422

Scheme 423

For on board diagnosis logic (Scheme 424)

Scheme 424

For DTC confirmation procedure (Scheme 425)

Scheme 425

For diagnostic procedure (Scheme 426)and (Scheme 427).

Scheme 426

Scheme 427

For component inspection (Scheme 428)

Scheme 428

CONSULT-II Reference Value In Data Monitor Mode & On Board Diagnosis Logic

For CONSULT-II reference value in data monitor mode and on board diagnosis logic (Scheme 429)

Scheme 429

For DTC confirmation procedure (Scheme 430)

Scheme 430

For diagnostic procedure (Scheme 431)- (Scheme 433).

Scheme 431

Scheme 432

Scheme 433

For component inspection (Scheme 434)

Scheme 434

CONSULT-II Reference Value In Data Monitor Mode & On Board Diagnosis Logic For EVAP Control System Pressure Sensor

For CONSULT-II reference value in data monitor mode and on board diagnosis logic for EVAP control system pressure sensor (Scheme 435)

Scheme 435

For DTC confirmation procedure (Scheme 436)

Scheme 436

For diagnostic procedure (Scheme 437)- (Scheme 439).

Scheme 437

Scheme 438

Scheme 439

For component inspection (Scheme 440)

Scheme 440

For CONSULT-II reference value in data monitor mode and on board diagnosis logic for EVAP control system pressure sensor (Scheme 441)

Scheme 441

For DTC confirmation procedure (Scheme 442)

Scheme 442

For diagnostic procedure (Scheme 443)- (Scheme 447).

Scheme 443

Scheme 444

Scheme 445

Scheme 446

Scheme 447

For component inspection (Scheme 448)

Scheme 448

For on board diagnosis logic (Scheme 449)

Scheme 449

For DTC confirmation procedure (Scheme 450)and (Scheme 451).

Scheme 450

Scheme 451

For diagnostic procedure (Scheme 452)- (Scheme 457).

Scheme 452

Scheme 453

Scheme 454

Scheme 455

Scheme 456

Scheme 457

For component inspection (Scheme 458)- (Scheme 460).

Scheme 458

Scheme 459

Scheme 460

For on board diagnosis logic (Scheme 461)

Scheme 461

For DTC confirmation procedure (Scheme 462)

Scheme 462

Note. For views of evaporative emission line drawings (Scheme 411)and (Scheme 412).

For diagnostic procedure (Scheme 463)- (Scheme 468).

Scheme 463

Scheme 464

Scheme 465

Scheme 466

Scheme 467

Scheme 468

Note. For inspection of fuel tank pressure sensor (Scheme 375) For inspection of EVAP control system pressure sensor (Scheme 448) For inspection of refueling control valve (Scheme 460) For inspection of EVAP canister purge volume control solenoid valve (Scheme 569)

For water separator component inspection (Scheme 469)

Scheme 469

Turn ignition on. Select DATA MONITOR with scan tool. Start engine and wait a maximum of 2 consecutive minutes. If 1st trip DTC is detected, go to DIAGNOSTIC PROCEDURE . If 1st trip DTC is not detected, system is okay at this time.

For diagnostic procedure (Scheme 470)and (Scheme 471).

Scheme 470

Scheme 471

For on board diagnosis logic (Scheme 472)

Scheme 472

For on DTC confirmation procedure (Scheme 473)

Scheme 473

For diagnostic procedure (Scheme 474)and (Scheme 475).

Scheme 474

Scheme 475

On Board Diagnosis Logic & DTC Confirmation Procedure

For on board diagnosis logic and DTC confirmation procedure (Scheme 476)

Scheme 476

Overall Function Check & Diagnostic Procedure

For overall function check and diagnostic procedure (Scheme 477)

Scheme 477

For on board diagnosis logic and DTC confirmation procedure (Scheme 478)

Scheme 478

For diagnostic procedure (Scheme 479)

Scheme 479

For diagnostic procedure (Scheme 480)

Scheme 480

For CONSULT-II reference value in data monitor mode and on board diagnosis logic (Scheme 481)

Scheme 481

Turn ignition on. Select DATA MONITOR mode with SCAN TOOL. Start engine and let it idle for at least 5 seconds. If 1st trip DTC is detected, go to DIAGNOSTIC PROCEDURE . If 1st trip DTC is not detected, system is okay at this time.

For diagnostic procedure (Scheme 482)and (Scheme 483).

Scheme 482

Scheme 483

For component inspection (Scheme 484)

Scheme 484

On Board Diagnosis Logic & Fail-Safe Mode

For on board diagnosis logic and fail-safe mode (Scheme 485)

Scheme 485

DTC Confirmation Procedures "A", "B" & "C"

For DTC confirmation procedures "A", "B" and "C" (Scheme 486)

Scheme 486

For diagnostic procedure (Scheme 487)

Scheme 487

On Board Diagnosis Logic, Fail-Safe Mode & DTC Confirmation Procedure

For on board diagnosis logic, fail-safe mode and DTC confirmation procedure (Scheme 488)

Scheme 488

For diagnostic procedure (Scheme 489)and (Scheme 490).

Scheme 489

Scheme 490

For diagnostic procedure (Scheme 491)and (Scheme 492).

Scheme 491

Scheme 492

For DTC confirmation procedure (Scheme 493)

Scheme 493

For diagnostic procedure (Scheme 494)and (Scheme 495).

Scheme 494

Scheme 495

For component inspection (Scheme 496)

Scheme 496

For diagnostic procedure (Scheme 497)

Scheme 497

For component inspection (Scheme 498)

Scheme 498

For DTC confirmation procedure (Scheme 499)

Scheme 499

For diagnostic procedure (Scheme 500)and (Scheme 501).

Scheme 500

Scheme 501

For component inspection (Scheme 502)

Scheme 502

For DTC confirmation procedure (Scheme 503)

Scheme 503

For diagnostic procedure (Scheme 504)

Scheme 504

For diagnostic procedure (Scheme 505)- (Scheme 507).

Scheme 505

Scheme 506

Scheme 507

For component inspection (Scheme 508)

Scheme 508

For diagnostic procedure (Scheme 509)and (Scheme 510).

Scheme 509

Scheme 510

For component inspection (Scheme 511)

Scheme 511

For diagnostic procedure (Scheme 512)

Scheme 512

For component inspection (Scheme 513)

Scheme 513

For diagnostic procedure (Scheme 514)- (Scheme 516).

Scheme 514

Scheme 515

Scheme 516

For component inspection (Scheme 517)

Scheme 517

For DTC confirmation procedure (Scheme 518)

Scheme 518

For diagnostic procedure (Scheme 519)and (Scheme 520).

Scheme 519

Scheme 520

For component inspection (Scheme 521)and (Scheme 522).

Scheme 521

Scheme 522

For DTC confirmation procedure (Scheme 523)

Scheme 523

For diagnostic procedure (Scheme 524)- (Scheme 526).

Scheme 524

Scheme 525

Scheme 526

For component inspection (Scheme 527)

Scheme 527

For DTC confirmation procedure (Scheme 528)

Scheme 528

For diagnostic procedure (Scheme 529)- (Scheme 532).

Scheme 529

Scheme 530

Scheme 531

Scheme 532

For component inspection (Scheme 533)

Scheme 533

For DTC confirmation procedure (Scheme 534)

Scheme 534

For diagnostic procedure (Scheme 535)- (Scheme 538).

Scheme 535

Scheme 536

Scheme 537

Scheme 538

For component inspection (Scheme 539)

Scheme 539

For on board diagnosis logic and DTC confirmation procedure (Scheme 540)

Scheme 540

Note. For diagnostic procedure of closed loop control, use diagnostic procedure for DTC P0133 and P0153. See DTC P0133 & P0153: HEATED OXYGEN SENSOR 1 .

For overall function check (Scheme 541)

Scheme 541

For diagnostic procedure (Scheme 542)- (Scheme 545).

Scheme 542

Scheme 543

Scheme 544

Scheme 545

For DTC confirmation procedure (Scheme 546)

Scheme 546

For diagnostic procedure (Scheme 547)and (Scheme 548).

Scheme 547

Scheme 548

For component inspection (Scheme 549)

Scheme 549

For diagnostic procedure (Scheme 550)

Scheme 550

For diagnostic procedure (Scheme 551)

Scheme 551

For on board diagnosis logic, fail-safe mode and DTC confirmation procedure (Scheme 552)

Scheme 552

For diagnostic procedure (Scheme 553)and (Scheme 554).

Scheme 553

Scheme 554

For on board diagnosis logic (Scheme 555)

Scheme 555

For DTC confirmation procedure (Scheme 556)and (Scheme 557).

Scheme 556

Scheme 557

Note. For views of evaporative emission line drawings (Scheme 411)and (Scheme 412). For inspection of refueling control valve (Scheme 460)

For diagnostic procedure (Scheme 558)- (Scheme 563).

Scheme 558

Scheme 559

Scheme 560

Scheme 561

Scheme 562

Scheme 563

For component inspection (Scheme 564)

Scheme 564

For on board diagnosis logic and DTC confirmation procedure (Scheme 565)

Scheme 565

For diagnostic procedure (Scheme 566)- (Scheme 568).

Scheme 566

Scheme 567

Scheme 568

For component inspection (Scheme 569)

Scheme 569

For DTC confirmation procedure (Scheme 570)

Scheme 570

For diagnostic procedure (Scheme 571)and (Scheme 572).

Scheme 571

Scheme 572

For component inspection (Scheme 573)

Scheme 573

For DTC confirmation procedure (Scheme 574)

Scheme 574

For diagnostic procedure (Scheme 575)and (Scheme 576).

Scheme 575

Scheme 576

For component inspection (Scheme 577)

Scheme 577

For on board diagnosis logic (Scheme 578)

Scheme 578

For DTC confirmation procedure (Scheme 579)

Scheme 579

Note. For inspection of refueling control valve (Scheme 460)

For diagnostic procedure (Scheme 580)- (Scheme 585).

Scheme 580

Scheme 581

Scheme 582

Scheme 583

Scheme 584

Scheme 585

For component inspection (Scheme 586)

Scheme 586

For on board diagnosis logic (Scheme 587)

Scheme 587

Turn ignition on. Select DATA MONITOR with scan tool. Wait at least 5 seconds. If 1st trip DTC is detected, go to DIAGNOSTIC PROCEDURE . If 1st trip DTC is not detected, system is okay at this time.

For diagnostic procedure (Scheme 588)

Scheme 588

DTC Confirmation Procedures

For DTC confirmation procedures (Scheme 589)

Scheme 589

For diagnostic procedure (Scheme 590)

Scheme 590

For component inspection (Scheme 591)

Scheme 591

Turn ignition on. Select DATA MONITOR with scan tool. Start engine and wait at least 5 seconds. If 1st trip DTC is detected, go to DIAGNOSTIC PROCEDURE . If 1st trip DTC is not detected, system is okay at this time.

For diagnostic procedure (Scheme 592)- (Scheme 594).

Scheme 592

Scheme 593

Scheme 594

For component inspection (Scheme 595)

Scheme 595

Note. Always perform test when ambient temperature is 41-86°F (5-30°C).

1. Turn ignition on. Start engine and warm to normal operating temperature.
2. Turn ignition off and wait at least 10 seconds. Start engine and let it idle for at least 70 seconds.
3. Select VC CUT/V BP/V P1491 of EVAPORATIVE SYSTEM in DTC WORK SUPPORT mode with CONSULT-II.
4. Press START on CONSULT-II screen. When the following conditions are met, TESTING will be displayed on CONSULT-II screen. ENG SPEED: more than 500 RPM. Vehicle speed: more than 23 MPH. B/FUEL SCHDL: 1.0-10.0 msec. Maintain conditions continuously until TESTING changes to COMPLETED (it will take at least 30 seconds). If TESTING is not displayed after 5 minutes, retry from step 2 .
5. Press SELF-DIAG RESULTS. If NG is displayed, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S03481326542003121500000) . If OK is displayed, system is okay at this time.

Note. Use the following test to check overall function of vacuum cut valve by-pass valve. During this test, 1st trip DTC may not be confirmed.

Remove vacuum cut valve and vacuum cut valve by-pass valve as an assembly. (Scheme 596) Apply vacuum to port "A". (Scheme 596) Vacuum should not exist at port "B". Apply vacuum to port "B". Vacuum should exist at port "A". Blow air in port "B". Air should flow out of port "A" with some resistance. Using jumper wires, apply battery voltage to by-pass valve terminals. Air should flow freely through ports "A" and "B" in both directions. If operation is as specified, system is okay at this time. If operation is not as specified, go to DIAGNOSTIC PROCEDURE.

Scheme 596

Note. For inspection of refueling control valve (Scheme 460)

For diagnostic procedure (Scheme 597)- (Scheme 600).

Scheme 597

Scheme 598

Scheme 599

Scheme 600

For component inspection (Scheme 601)

Scheme 601

1. Turn ignition on. Select P/N POSI SW in DATA MONITOR mode with CONSULT-II.
2. Check P/N POSI SW signal under the following conditions. With transmission in Park or Neutral, ON should be displayed. With transmission not in Park or Neutral, OFF should be displayed. If operation is as specified, go to next step. If operation is not as specified, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S26501154332003121500000) .
3. Select DATA MONITOR mode with CONSULT-II. Start engine and warm to normal operating temperature.
4. Maintain the following conditions for at least 60 consecutive seconds: ENG SPEED: more than 1200 RPM. COOLAN TEMP/S: more than 158°F (70°C). B/FUEL SCHDL: 2-31 msec. VHCL SPEED SE: more than 40 MPH. If 1st trip DTC is detected, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S26501154332003121500000) . If 1st trip DTC is not detected, system is okay at this time.

Note. Use the following test to check overall function of PNP switch circuit. During this test, DTC may not be confirmed.

To check overall function of PNP switch circuit, turn ignition on. Measure voltage between body ground and PNP switch signal circuit at ECM terminal No. 80 (Gray/Red wire) by backprobing. see scheme 23and see scheme 44. With transmission in Park or Neutral, voltage should be about zero volts. With transmission in any other position, battery voltage should exist. If voltage is as specified, system is okay at this time. If voltage is not as specified, go to DIAGNOSTIC PROCEDURE.

For diagnostic procedure (Scheme 602)and (Scheme 603).

Scheme 602

Scheme 603

1. Turn ignition on. Select DATA MONITOR mode with scan tool. Start engine. Drive vehicle at 12 MPH or more for at least 5 seconds without depressing brake pedal.
2. If 1st trip DTC is detected, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S41800845492003121500000) . If 1st trip DTC is not detected, system is okay at this time.

1. Check TCM for DTCs. See appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS. If DTC is set, repair transmission control system as necessary. If DTC is not set, go to next step.
2. Check VDC/TCS/ABS control unit for DTCs. See appropriate ANTI-LOCK/TRACTION CONTROL article in BRAKES. If DTC is set, repair VDC/TCS/ABS system as necessary. If DTC is not set, go to next step.
3. Check instrument cluster function. Repair as necessary. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Test is complete.

1. Turn ignition on. Fully depress brake pedal for at least 5 seconds. Clear DTC with scan tool. Select DATA MONITOR mode with scan tool.
2. If 1st trip DTC is detected, go to «DIAGNOSTIC PROCEDURE»(ref-159509-S01733199752003121500000) . If 1st trip DTC is not detected, system is okay at this time.

1. Turn ignition off. Check stop lamp operation. If stop lamps operate properly, go to step 4. If stop lamps do not operate properly, go to next step.
2. Disconnect stop lamp switch harness connector. (Scheme 604) Measure voltage between ground and stop lamp switch harness connector terminal No. 1 (Red/Yellow wire). If battery voltage exists, go to step 4. If battery voltage does not exist, go to next step.
3. Check the following: Check for poor connection at White, 4-pin in-line harness connector M401 terminal No. 1 (Red/Yellow wire). Connector M401 is located near stop lamp switch. (Scheme 259) Check Black, 20-pin joint connector No. 7 (connector M46) located behind center of instrument panel. (Scheme 259)and see scheme 50. Check for poor connection at fuse block No. 1 connector M1 terminal 3B (Blue/Black wire). see scheme 45 Check fuse No. 17 (15-amp) located in fuse block No. 1. Check for open or short between stop lamp switch and battery. Repair as necessary.
4. Turn ignition off. Disconnect ECM harness connector. see scheme 23 Disconnect stop lamp switch harness connector. (Scheme 604) Check continuity of Red/White wire between stop lamp switch harness connector terminal No. 2 and ECM harness connector terminal No. 106. see scheme 44 Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If circuit is okay, go to step 6.
5. Check the following: Check for poor connection at White, 4-pin in-line harness connector M401 terminal No. 2 (Red/White wire). Connector M401 is located near stop lamp switch. (Scheme 259) Check for poor connection at Super Multiple Junction harness connector F105 terminal 22T (Red/White wire). (Scheme 264)and see scheme 48. Check Black, 20-pin joint connector No. 7 (connector M46) located above stop lamp switch. (Scheme 259)and see scheme 50. Check for open or short between stop lamp switch and ECM. Repair as necessary.
6. Check continuity between stop lamp switch terminals. With brake pedal depressed, continuity should exist. With brake pedal fully released, continuity should not exist. If continuity is as specified, go to next step. If continuity is not as specified, replace stop lamp switch.
7. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.

Scheme 604

For DTC confirmation procedure (Scheme 605)

Scheme 605

For diagnostic procedure (Scheme 606)and (Scheme 607).

Scheme 606

Scheme 607

For component inspection (Scheme 608)

Scheme 608

For DTC confirmation procedure (Scheme 609)

Scheme 609

For diagnostic procedure (Scheme 610)and (Scheme 611).

Scheme 610

Scheme 611

For component inspection (Scheme 612)

Scheme 612

For DTC confirmation procedure (Scheme 613)

Scheme 613

For diagnostic procedure (Scheme 614)and (Scheme 615).

Scheme 614

Scheme 615

For component inspection (Scheme 616)

Scheme 616

For DTC confirmation procedure (Scheme 617)

Scheme 617

For diagnostic procedure (Scheme 618)and (Scheme 619).

Scheme 618

Scheme 619

For component inspection (Scheme 620)

Scheme 620

Turn ignition on and wait at least 3 seconds. Select DATA MONITOR mode with scan tool. If 1st trip DTC is detected, go to DIAGNOSTIC PROCEDURE . If 1st trip DTC is not detected, system is okay at this time.

Turn ignition on. Select CAN COMM SIGNALS in DATA MONITOR mode with scan tool. If OK is displayed for all circuits, system is okay. If OK is not displayed for all circuits, repair communication problem. See appropriate MULTIPLEX CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT.