Home ReviewsRefund
Home/Dodge/Neon/Dodge Neon II (1999-2005)/Repair manual/Testing & Diagnostics/Engine Controls - Self-Diagnostics: Other
Contents Wiring diagrams Section: Testing & Diagnostics All sections

Engine Controls - Self-Diagnostics: Other Dodge Neon II

Testing & Diagnostics ~7890 words

Malfunction Indicator Light (MIL)

MIL may also be referred to as CHECK ENGINE light. MIL is located on right side of instrument cluster and is represented by an engine symbol. When ignition is first turned on, MIL should come on briefly to verify bulb and circuit operation, and then go off. If MIL does not operate as specified, diagnose MIL concern. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.

Powertrain Control Module (PCM) monitors several different engine control system circuits. If a malfunction occurs which affects vehicle emissions, a Diagnostic Trouble Code (DTC) will be stored in PCM memory and PCM will enter limp-in mode. In limp-in mode, PCM substitutes values for the failed component to continue engine operation, but a loss of good driveability may result. When DTC is stored in PCM memory, PCM will turn on MIL and MIL will remain on steady. If problem exists which does not affect vehicle emissions, a DTC will be stored in PCM but MIL will not be turned on.

PCM might not store a DTC for a monitored circuit even though a malfunction has occurred. This may happen because one of the criteria for the DTC has not been met. Criteria may be a specific engine RPM range, engine temperature and/or voltage input to PCM. For example, assume criteria for DTC requires PCM to monitor a specified sensor output circuit only when engine operates at 750-2000 RPM. If sensor output circuit becomes shorted to ground when engine is operating at 2400 RPM, DTC will not be stored, as short to ground occurred at 2400 RPM which exceeds the limit when PCM monitors the circuit.

If PCM detects an active engine misfire severe enough to cause catalytic converter damage, MIL will immediately start flashing to warn driver of possible catalytic converter damage and DTC will be stored. PCM may turn off MIL if malfunction is not detected during 3 consecutive trips, 3 consecutive engine misfire monitor tests or fuel system monitor tests. For additional information on good trips, see TRIP INDICATOR . For additional information on engine misfire monitor and fuel system monitor, see MONITORED CIRCUITS . PCM performs engine misfire and fuel system monitor tests within predetermined engine speed (RPM) and load operating conditions.

DTCs may be retrieved for system diagnosis. See RETRIEVING DIAGNOSTIC TROUBLE CODES . System malfunctions are identified as either hard failures or intermittent failures. For additional information on hard failures or intermittent failures, see HARD FAILURES or INTERMITTENT FAILURES .

Monitored Circuits

The PCM contains electronic circuit monitors that monitor fuel, vehicle emissions, engine and ignition system performance. Monitors use information from various sensor circuits for system monitoring. Monitors do not indicate a specific component failure, but indicate an implied failure within a specified system, and that problem must be diagnosed. If any monitor detects a problem affecting vehicle emissions, a Diagnostic Trouble Code (DTC) will be stored in PCM memory. The following monitors are used.

  1. Catalyst Monitor
  2. Engine Misfire Monitor
  3. Evaporative Emissions System Leak And Purge Detection Pump Monitor
  4. Exhaust Gas Recirculation System Monitor
  5. Fuel System Monitor
  6. Oxygen Sensor Monitor
  7. Oxygen Sensor Heater Monitor

After 3 good trips, PCM will turn off the MIL. At that time, the PCM will automatically switch the trip counter to a warm-up cycle counter. The PCM will erase DTCs after 40 warm-up cycles if the recent malfunction does not reoccur in that time. For additional information on good trips and warm-up cycles, see TRIP INDICATOR .

Non-Monitored Circuits

The PCM does not monitor all circuits, conditions and systems that could cause a malfunction or driveability problem. However, problems with these systems may cause PCM to store DTCs for other systems or components.

For example, a fuel pressure problem will not cause a DTC directly, but could cause a rich/lean condition or misfire. This could cause PCM to store an oxygen sensor DTC. The major non-monitored circuits are identified as follows.

  1. Cylinder Compression
  2. Engine Timing
  3. Excessive Oil Consumption
  4. Exhaust System
  5. Fuel Injectors
  6. Fuel Requirements
  7. PCM Grounds
  8. Secondary Ignition System
  9. Throttle Body Airflow
  10. Vacuum Assist

Trip Indicator

The trip is essential for running monitors and turning off the MIL. A trip is defined as a set of vehicle operating conditions that must be met for a specific monitor to run. All trips begin with an ignition key cycle. Good trip counters are as follows: specific good trip, fuel system good trip and misfire good trip.

  1. Specific Good Trip The term good trip has different meanings depending on the circumstances. If the MIL is off, a good trip is defined as when the oxygen sensor monitor and the catalyst monitor have completed in the same drive cycle. If the MIL is on and a DTC was set by the fuel system monitor or misfire monitor, vehicle must be operated in the similar conditions window for a specified amount of time. If MIL is on and a DTC was set by a PCM task manager commanded once-per-trip monitor (oxygen sensor/heater monitor, catalyst monitor, purge flow monitor, leak detection monitor or EGR monitor), a good trip is when the monitor is passed on the next engine start-up. If the MIL is on and any other emissions DTC is set (not an OBD-II monitor), a good trip is when the oxygen sensor monitor and catalyst monitor have completed, or 2 minutes of engine run time has occurred (if the oxygen sensor monitor and catalyst monitor has stopped running). NOTE: For more information on similar conditions window, see «SIMILAR CONDITIONS WINDOW»(ref-133003-S37585476862002021100000) .
  2. Fuel System Good Trip To count as a good trip (3 required) and turn off the MIL, the following conditions must be met. Engine must be in closed loop, must be operating in similar conditions window and short term multiplied by long term must be less than threshold value.
  3. Misfire Good Trip If operating in similar conditions window and 1000 engine revolutions have occurred with no misfires, the PCM will count one good trip (3 required) in order to turn off MIL.
  4. Warm-Up Cycles Once the MIL has been turned off by the good trip counter, the PCM will automatically switch to a warm-up cycle counter that can be viewed by the DRBIII(R). Warm-up cycles are used to clear DTCs and Freeze Frame data from PCM memory. Forty warm-up cycles are necessary to clear DTCS and Freeze Frame data. A warm-up cycle is defined as the engine is started, an increase of 40°F (4.4°C) in engine coolant temperature exists after engine is started and engine coolant temperature reaches at least 160°F (71°C).

Similar Conditions Window

Similar Conditions Window data can be viewed by using the DRBIII(R). The similar conditions window displays information about the engine operation during a monitor. Engine load (absolute manifold pressure) and engine RPM are stored in this window when a failure occurs. This information is useful in determining when a failure occurred. There are 2 different similar conditions windows, fuel system and misfire. For more information on similar conditions windows, see SELF-DIAGNOSTIC SYSTEMS in appropriate THEORY & OPERATION article.

Hard Failures

Hard failures cause MIL to illuminate and remain on until problem is repaired. If MIL comes on and remains on during vehicle operation, cause of malfunction must be determined by retrieving DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES . If a sensor fails, PCM will use substitute value in its calculations to continue engine operation. In this condition, commonly known as limp-in mode, vehicle runs but driveability will not be optimum.

Intermittent Failures

Intermittent failures may cause MIL to flicker or illuminate and go out after intermittent failure goes away. However, the corresponding DTC will be retained in PCM memory. If related failure does not reoccur within 40 warm-up cycles, related DTC will be erased from PCM memory. Most intermittent failures are caused by a sensor, electrical connector or wiring related problems. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - CARS - EXCEPT SEBRING COUPE & STRATUS COUPE article.

SERVICE PRECAUTIONS

Before proceeding with system diagnosis, following precautions must be followed

  1. Ensure fuel pressure is released before disconnecting any fuel line or fuel fitting, as fuel system is under pressure and may cause personal injury. See «FUEL SYSTEM PRESSURE RELEASE»(ref-133003-S21114987412002021100000) .
  2. When using diagnostic tests for diagnosis, DO NOT skip any steps or incorrect diagnosis may result. When instructed to disconnect any connector, check that the connector is clean and in good condition after disconnecting the connector. Repair or clean connector as necessary. Always perform indicated verification procedure after repairs are made. See «VERIFICATION TESTS»(ref-133003-S21910325102002021100000) .
  3. When using a jumper wire, ensure either jumper wire or circuit is fuse-protected.
  4. Ensure ignition is off before disconnecting connector from any control module.
  5. When checking voltage or continuity at any control module, probe connector for control module from pin side. DO NOT probe wire through insulation or backprobe connector (unless instructed to do otherwise in test procedure).
  6. DO NOT cause short circuits when performing electrical tests. This will set additional Diagnostic Trouble Codes (DTC), making diagnosis of original problem more difficult.
  7. When checking for spark, ensure no fuel leaks exist and spark plug cable or coil wire is not more than 1/4" from engine ground. If spark plug or coil wire is more than 1/4" from engine ground, damage to vehicle electronics and/or Powertrain Control Module (PCM) may result.
  8. DO NOT prolong testing of fuel injectors or engine may hydrostatically lock.
  9. If replacing PCM, correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into PCM to prevent DTCs from being set in Supplemental Restraint System (SRS) Air Bag Control Module (ACM), Controller Anti-Lock Brake (CAB) and Sentry Key Immobilizer Module (SKIM), if equipped. See «POWERTRAIN CONTROL MODULE»(ref-133003-S41684016202002021100000) under PROGRAMMING.
  10. If replacing PCM on models with a Sentry Key Immobilizer Module (SKIM), secret key data must be updated to enable engine starting. See «SENTRY KEY IMMOBILIZER MODULE»(ref-133003-S15852222992002021100000) under PROGRAMMING

Using Odometer Display

  1. DTCs can be retrieved by cycling ignition switch. To retrieve DTCs, cycle ignition key on-off-on-off-on within 5 seconds. Instrument cluster odometer will display DTC. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-133003-S26406645532002021100000) . After repair is complete, clear DTCs from PCM memory and perform appropriate verification test. See «VERIFICATION TESTS»(ref-133003-S21910325102002021100000) .
  2. If no DTCs are displayed, odometer will display either P1684 and DONE, or only DONE. DTC P1684 is only a status and indicates that PCM memory has been cleared within the last 50 ignition cycles. No problem exists. DONE indicates that no DTCs are present and procedure is complete. If no DTCs are present go to one of the following: For Air Conditioning (A/C) system problems, see appropriate A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. For Anti-Lock Brake System (ABS) problems, see appropriate ANTI-LOCK article in BRAKES. For charging system problems, see appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. For control module communication problems, see appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT. For Speed Control (S/C) problems and servicing information, see appropriate CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT. For starting or driveability problems, see «TROUBLE SHOOTING - NO CODES - CARS - EXCEPT SEBRING COUPE & STRATUS COUPE»(ref-142307) article for diagnosis by symptom. For transmission electronic controls system problems, see appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.

FUEL SYSTEM PRESSURE RELEASE

CAUTIONFuel system is under high pressure. ALWAYS release fuel pressure before attempting to open system for testing or component replacement. DO NOT allow fuel to flow onto engine or electrical parts while testing fuel system components.
  1. Turn ignition off. Remove fuel pump relay from Power Distribution Center (PDC).
  2. Start engine and allow engine to idle until engine stalls. Attempt restarting engine until engine will no longer run. Turn ignition off.
  3. Place a shop towel under fuel line quick-connector at fuel rail. Use care when disconnecting fuel lines, as some fuel pressure may still exist in fuel lines. Disconnect fuel line quick-connector. Reinstall fuel pump relay in PDC.
  4. Erase any DTCs that may have set after fuel pressure release procedure. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-133003-S22377824322002021100000) under SELF-DIAGNOSTIC SYSTEM.

PROGRAMMING

Note. Programming procedures are written specifically for Chrysler's Diagnostic Readout Box (DRBIII(R)) scan tool. A generic scan tool may not be capable of performing all necessary procedures.

POWERTRAIN CONTROL MODULE

Note. Before replacing the Powertrain Control Module (PCM) for a failed driver, control circuit or ground circuit, be sure to check the related component/circuit integrity for failures not detected due to a double fault in the circuit. Most PCM driver/control circuit failures are caused by internal failure to components (i.e. relay and solenoids) and short circuits (i.e. 12-volt pull-ups, drivers and ground sensors). These failures are difficult to detect when a double fault has occurred and only one DTC has set.

Note. If the PCM and the Sentry Key Immobilizer Module (SKIM) are replaced at the same time, program the VIN into the PCM first. All vehicle keys will then need to be replaced and programmed to the new SKIM. See SENTRY KEY IMMOBILIZER MODULE .

Note. The Sentry Key Immobilizer System (SKIS) secret key is an identification code that is unique to each SKIS. This code is programmed and stored in the PCM, SKIM and ignition key transponder chip. When replacing the PCM it is necessary to program the secret key into the PCM

Programming PCM

  1. To program PCM, connect DRBIII(R) to Data Link Connector (DLC). DLC is located below driver's side of instrument panel. (Схема №4) Place transmission in Park or Neutral. Turn the ignition on, with the engine off.
  2. Using DRBIII(R), select THEFT ALARM, SKIM then MISCELLANEOUS.
  3. Select PCM REPLACED.
  4. Enter secured access mode by entering the vehicle four-digit PIN.
  5. Press ENTER to transfer the secret key (the SKIM will send the secret key to the PCM).

SENTRY KEY IMMOBILIZER MODULE

Note. If the Powertrain Control Module (PCM) and the Sentry Key Immobilizer Module (SKIM) are replaced at the same time, program the Vehicle Identification Number (VIN) into the PCM first. All vehicle keys will then need to be replaced and programmed to the new SKIM.

Programming SKIM

  1. Connect DRBIII(R) to Data Link Connector (DLC). DLC is located below driver's side of instrument panel. (Схема №4) Place transmission in Park or Neutral. Turn the ignition on, with the engine off.
  2. With DRBIII(R), select THEFT ALARM, SKIM then MISC.
  3. Select SKIM MODULE REPLACEMENT GASOLINE
  4. Program the 4-digit Personal Identification Number (PIN) into the SKIM.
  5. Select COUNTRY CODE and enter the correct country.
  6. Select UPDATE VIN (the SKIM will learn the VIN from the PCM).
  7. Press ENTER to transfer the VIN (the PCM will send the VIN to the SKIM).
  8. The DRBIII(R) will ask if you want to transfer the secret key from the PCM. This will ensure the current vehicle ignition keys will still operate the Sentry Key Immobilizer System (SKIS).

Programming Ignition Keys To SKIM

  1. Connect DRBIII(R) to Data Link Connector (DLC). (Схема №4) Place transmission in Park or Neutral. Turn the ignition on, with the engine off.
  2. With DRBIII(R), select THEFT ALARM, SKIM THEN MISC.
  3. Select PROGRAM IGNITION KEYS.
  4. Enter secured access mode by entering the vehicle 4-digit Personal Identification Number (PIN). Follow DRBIII(R) prompts. If ignition key programming is unsuccessful, the DRBIII(R) will display one of the following messages: Programming Not Attempted - The DRBIII(R) attempts to read the programmed key status and there are no keys programmed in the SKIM memory. Programming Key Failed- The SKIM is unable to program a key because it has a faulty transponder or the key is programmed to another vehicle. 8 Keys Already Learned, Programming Not Done - SKIM transponder identification memory is full. Obtain up to 8 keys to be programmed. Using the DRBIII(R), erase all ignition keys by selecting MISC and ERASE ALL CURRENT IGN KEYS, then return to step 2. Learned Key In Ignition - Ignition key transponder identification is currently programmed in SKIM memory.

SUMMARY

If no Diagnostic Trouble Codes (DTC) are present and a no-start condition exists, proceed to BASIC DIAGNOSTIC PROCEDURES - NEON article. If no DTCs are present and a driveability condition exists, proceed to TROUBLE SHOOTING - NO CODES - CARS - EXCEPT SEBRING COUPE & STRATUS COUPE article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).

Monitored & Set Conditions

Note. Ambient air temperature sensor may also be referred to as battery temperature sensor.

Ambient air temperature sensor circuit is monitored with ignition on, engine coolant temperature more than 160°F (71°C) and no Inlet Air Temperature (IAT) sensor faults present. DTC will set after 5 warm cycles, odometer mileage has increased 196.6 miles and inlet air temperature has increased less than 37.4°F (3°C). A warm cycle is when engine coolant temperature increases from more than 40°F (4.4°C) to a minimum of 160°F (71°C). This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

Possible Causes

  1. IAT Signal Circuit High Resistance
  2. IAT Sensor Voltage Less Than One Volt
  3. Intermittent Condition
  4. Sensor Ground Circuit High Resistance
  5. PCM

Manifold Absolute Pressure (MAP) sensor circuit is monitored with the ignition key on, no cam or crank signal within 75 milliseconds and engine speed at less than 250 RPM. DTC will set when PCM senses the voltage from the MAP sensor to be less than 2.196 volts but more than 0.0392 volt for 300 milliseconds.

  1. Defective MAP Sensor
  2. Defective PCM
  3. Signal Circuit Open Or Shorted To Ground
  4. 5-Volt Supply Circuit Open Or Shorted To Ground

Manifold Absolute Pressure (MAP) sensor circuit is monitored with engine speed 600-3500 RPM, Throttle Position (TP) sensor voltage less than 1.2 volts and battery voltage more than 10.0 volts. DTC will set when PCM senses MAP sensor signal voltage is less than .0392 volt for 1.7 seconds.

  1. Intermittent Condition
  2. MAP Sensor Internal Failure
  3. MAP Sensor Signal Circuit Shorted To Ground
  4. MAP Sensor Signal Circuit Shorted To Sensor Ground Circuit
  5. PCM MAP Sensor Signal
  6. PCM 5-Volt Supply Circuit
  7. 5-Volt Supply Circuit Open
  8. 5-Volt Supply Circuit Shorted To Ground

Manifold Absolute Pressure (MAP) sensor circuit is monitored with engine speed at 600-3500 RPM, Throttle Position (TP) sensor voltage less than 1.2 volts for more than 1.7 seconds, and battery voltage more than 10.0 volts. DTC will set when MAP sensor signal voltage is more than 4.96 volts.

  1. Intermittent Condition
  2. MAP Sensor Internal Failure
  3. MAP Sensor Signal Circuit Open
  4. MAP Sensor Signal Circuit Shorted To Battery Voltage
  5. MAP Sensor Signal Circuit Shorted To 5-Volt Supply Circuit
  6. PCM
  7. Sensor Ground Circuit Open

Engine Coolant Temperature (ECT) sensor circuit is monitored with ignition on and battery voltage more than 10.0 volts. DTC will set when the ECT sensor circuit voltage at the PCM is less than 0.5 volt for more than 2.6 seconds.

  1. Intermittent Condition
  2. ECT Sensor Internal Failure
  3. ECT Sensor Signal Circuit Shorted To Ground

Engine Coolant Temperature (ECT) sensor circuit is monitored with ignition on and battery voltage more than 10.0 volts. DTC will set when ECT sensor circuit voltage at the PCM is more than 4.96 volts for more than 2.6 seconds.

  1. Intermittent Condition
  2. ECT Sensor Internal Failure
  3. ECT Sensor Signal Circuit Shorted To Battery Voltage
  4. ECT Sensor Signal Circuit Open
  5. Sensor Ground Circuit Open
  6. PCM

Throttle Position (TP) sensor circuit is monitored with the engine running and no Manifold Absolute Pressure (MAP) sensor or TP sensor DTCs set. When the manifold vacuum is low, the TP sensor signal should be high. Conversely, when manifold vacuum is high, the TP sensor signal should be low. DTC will set if the MAP sensor and TP sensor do not respond within 4 seconds as stated above.

  1. Intermittent Condition
  2. High Resistance In 5-Volt Supply Circuit
  3. Resistance To Ground In 5-Volt Supply Circuit
  4. MAP Sensor
  5. High Resistance In MAP Sensor Signal Circuit
  6. Resistance To Ground In MAP Sensor Signal Circuit
  7. High Resistance In Sensor Ground Circuit
  8. PCM
  9. TP Sensor
  10. High Resistance In TP Sensor Signal Circuit
  11. Resistance To Ground In TP Sensor Signal Circuit

Throttle Position (TP) sensor circuit is monitored with the ignition on and battery voltage more than 10.0 volts. DTC will set when TP sensor voltage at the PCM is less than 0.16 volt for 0.7 second.

  1. Intermittent Condition
  2. TP Sensor Sweep
  3. 5-Volt Supply Circuit Shorted To Ground
  4. 5-Volt Supply Circuit Open
  5. TP Sensor Internal Failure
  6. TP Sensor Signal Circuit Shorted To Ground
  7. TP Sensor Signal Circuit Shorted To Sensor Ground
  8. TCM Internally Shorted TP Sensor Signal Circuit
  9. PCM 5-Volt Supply Circuit
  10. PCM TP Sensor Signal

Throttle Position (TP) sensor circuit is monitored with the ignition on and battery voltage more than 10.0 volts. DTC will set when TP sensor voltage at the PCM is more than 4.5 volts for 0.7 second.

  1. Intermittent Condition
  2. TP Sensor Sweep
  3. TP Sensor Signal Circuit Shorted to 5-Volt Supply Circuit Shorted
  4. TP Sensor Signal Circuit Shorted To Battery Voltage
  5. TP Sensor Internal Failure
  6. Sensor Ground Signal Open
  7. TP Sensor Signal Circuit Open
  8. PCM

DTC P0131 is monitored at engine shutdown O2 Heater Diagnostics test, then at subsequent cold start. Cold start is defined as engine coolant less than 100°F (37°C), ambient/battery sensor reading within 44°F (6.6°C), and engine coolant temperature more than 146°F (63°C) on the previous key-off. DTC will set when O2 sensor signal voltage is less than 0.078 volt for 5 seconds after starting engine. DTC P0137 is monitored after the engine runs for 119 seconds, with coolant temperature more than 176°F (80°C), and vehicle speed more than 40 mph. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM. DTC will set when O2 sensor signal voltage is less than 0.078 volt for 61 seconds after starting engine.

  1. Intermittent Condition
  2. O2 Sensor Operation
  3. O2 Sensor Signal Circuit Shorted To Ground
  4. O2 Sensor Signal Circuit Shorted To Sensor Ground
  5. O2 Sensor Signal Shorted To Heater Ground Circuit
  6. TP Sensor Signal Circuit Shorted To Ground
  7. PCM

DTC P0132 and P0138 are monitored with engine running for 119 seconds, battery voltage more than 10.0 volts, and coolant temperature more than 176°F (80°C). DTC will set when O2 sensor voltage is more than 1.29 volts for 30 seconds. DTC P0132 is a one-trip fault, and DTC P0138 is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. O2 Sensor Operation
  3. O2 Sensor Signal Circuit Shorted To Voltage
  4. O2 Sensor Signal Circuit Open
  5. O2 Sensor Ground Circuit Open
  6. PCM

DTC P0133 is monitored with engine running and when vehicle is driven more than 10 MPH with wide open throttle or just open for a minimum 200 seconds, coolant more than 158°F (70°C), and EVAP purge is active. Test performs in idle drive.

DTC P0133 will set when O2 sensor signal voltage is switching from less than 0.33 volt to more than 0.61 volt and back fewer times than required in 60 seconds. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

DTC P0139 is monitored with engine idling. For first part of test, if limits are exceeded, test passes. If test does not pass, second part of test runs with engine running for more than 295 seconds, ambient/battery temperature more than 44°F (7°C), barometric pressure more than 22.13 in. Hg, MAP sensor vacuum 13.8-21.6 in. Hg at 1400-2500 RPM and vehicle speed 22-60 MPH.

DTC P0139 will set when O2 signal voltage does not switch from less than 0.39 volt to more than 0.53 volt in 411 seconds of engine run time. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. Exhaust Leak
  3. O2 Sensor Signal Circuit Voltage Drop
  4. O2 Sensor Ground Circuit Voltage Drop
  5. O2 Sensor

DTC P0134 and P0140 are monitored with engine running for more than 121 seconds, coolant temperature more than 150.8°F (66°C) and engine in closed loop fuel control mode. On DTC P0140, vehicle speed must be more than 40 MPH. DTC will set when O2 sensor signal voltage is .35-.58 volt for 30 seconds, then 1.5 volts for 60 seconds. DTC P0134 is a one-trip fault, and DTC P0140 is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. O2 Sensor Operation
  3. O2 Sensor Ground Circuit Open
  4. O2 Sensor Signal Open
  5. O2 Sensor Ground Circuit Voltage Drop
  6. O2 Sensor Signal Circuit Voltage Drop
  7. PCM

1/1 Oxygen (O2) sensor circuit is monitored after engine has been idling for at least 12 seconds, with battery voltage more than 9.0 volts, engine coolant temperature less than 147°F (64°C) and ambient/battery temperature equal to or less than 27°F (-2.8°C). DTC will set when O2 sensor voltage is more than 3.0 volts for 30-90 seconds.

  1. Intermittent Condition
  2. O2 Sensor Heater Element
  3. O2 Sensor Heater Control Circuit Open
  4. O2 Sensor Heater Control Circuit Shorted To Ground
  5. ASD Relay Output Circuit Open
  6. PCM

1/2 Oxygen (O2) sensor circuit is monitored with engine running for 119 seconds, battery voltage more than 10.0 volts, and coolant temperature more than 176°F (80°C). DTC will set when O2 sensor voltage is more than 1.29 volts for 30 seconds. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. O2 Sensor Operation
  3. O2 Sensor Signal Circuit Shorted To Voltage
  4. O2 Sensor Signal Circuit Open
  5. O2 Sensor Ground Circuit Open
  6. PCM

1/2 Oxygen (O2) sensor circuit is monitored during vehicle shutdown after vehicle has been driven more than 10 miles with throttle open for a minimum of 3 minutes, and battery voltage more than 11.0 volts. DTC will set when O2 sensor voltage is more than 3 volts for 60-240 seconds.

  1. Intermittent Condition
  2. O2 Sensor Heater Element
  3. O2 Sensor Heater Ground Circuit Open
  4. ASD Relay Output Circuit Open

1/1 fuel system is monitored with engine running in closed loop mode, ambient temperature more than 20°F (-7°C) and altitude below 8000 feet. DTC will set if the PCM multiplies short term compensation by long term adaptive and a certain percentage is exceeded. A Freeze Frame is stored and the MIL illuminates. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. Restricted Fuel Supply Line
  3. Fuel Pump Inlet Strainer Plugged
  4. Fuel Pump Module
  5. Oxygen (O2) Sensor
  6. O2 Sensor Signal Circuit Shorted To Ground
  7. O2 Sensor Heater Operation
  8. Throttle Position (TP) Sensor Voltage More Than 0.92 Volt With Throttle Closed
  9. TP Sensor Sweep
  10. Manifold Absolute Pressure (MAP) Sensor Operation
  11. Engine Coolant Temperature (ECT) Sensor Operation
  12. Engine Mechanical Problem
  13. PCM

1/1 fuel system is monitored with engine running in closed loop mode, ambient temperature more than 20°F (-7°C) and altitude below 8000 feet. DTC will set if the PCM multiplies short term compensation by long term adaptive and the result is less than a certain percentage. A Freeze Frame is stored and the MIL illuminates. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. Oxygen (O2) Sensor
  3. O2 Sensor Heater Operation
  4. O2 Sensor Signal Circuit Shorted To Volage
  5. Evaporative Emission (EVAP) Purge Solenoid Operation
  6. Throttle Position (TP) Sensor Voltage More Than 0.92 Volt With Throttle Closed
  7. TP Sensor Sweep
  8. Manifold Absolute Pressure (MAP) Sensor Operation
  9. Engine Coolant Temperature (ECT) Sensor Operation
  10. Engine Mechanical Problem
  11. Fuel Filter/Pressure Regulator (High)
  12. PCM

Injector control circuits are monitored with battery voltage more than 10.0 volts, Automatic Shutdown (ASD) relay energized and engine speed less than 3000 RPM. DTC will set when no inductive spike is sensed after injector turns off.

  1. Intermittent Condition
  2. Fuel Injector
  3. ASD Relay Output Circuit Open
  4. Fuel Injector Driver Circuit Open
  5. Fuel Injector Driver Circuit Shorted To Ground
  6. PCM

Cylinder misfire is monitored any time the engine is running and the adaptive numerator has successfully updated. DTC P0300 will set when more than a 2 percent (2.5 percent LEV) misfire rate is measured during 2 trips at less than 3000 RPM or one trip at more than 3000 RPM. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS.

DTC P0301, P0302, P0303 or P0304 will set when more than a 2 percent (2.5 percent LEV) misfire rate is measured during 2 trips at less than 3000 RPM or with a 10-20 percent misfire rate during one trip. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS.

  1. Misfire Conditions No Longer Exist
  2. Fuel System Problem
  3. Secondary Ignition Or Mechanical Problem
  4. Erratic Camshaft Position (CMP)/Crankshaft Position (CKP) Sensor Signals
  5. Engine Mechanical Problem
  6. Other Possible Causes For Misfire

Crankshaft Position (CKP) sensor signal (crank reference signal) circuit is monitored during engine cranking. DTC will set when PCM senses no CKP sensor signal during engine cranking, and at least 8 Camshaft Position (CMP) sensor signals have occurred.

  1. Intermittent CMP Signal
  2. Intermittent Wiring
  3. Intermittent Condition
  4. 8-Volt Supply Circuit Shorted To Ground
  5. 8-Volt Supply Circuit Open
  6. 8-Volt Supply Circuit Shorted To Voltage
  7. CKP Sensor Signal Circuit Shorted Ground
  8. CKP Sensor Signal Circuit Open
  9. CKP Sensor Signal Circuit Shorted To Voltage
  10. CKP Sensor Signal Shorted To 8-Volt Supply Circuit
  11. Sensor Ground Circuit Open
  12. PCM 8-Volt Supply
  13. PCM CKP Sensor Signal
  14. CKP Sensor

Camshaft Position (CMP) sensor signal (cam reference signal) circuit is monitored when engine is cranking or running. DTC will set when PCM senses at least 5 seconds or 2.5 engine revolutions has past with Crankshaft Position (CKP) sensor signals present but no signals from CMP sensor.

  1. Intermittent CKP Sensor Signal
  2. Intermittent CMP Sensor Signal
  3. Intermittent Wiring
  4. Intermittent Condition
  5. 8-Volt Supply Circuit Shorted To Ground
  6. 8-Volt Supply Circuit Open
  7. 8-Volt Supply Circuit Shorted To Voltage
  8. CMP Sensor Signal Circuit Shorted Ground
  9. CMP Sensor Signal Circuit Open
  10. CMP Sensor Signal Circuit Shorted To Voltage
  11. CMP Sensor Signal Shorted To 8-Volt Supply Circuit
  12. Sensor Ground Circuit Open
  13. PCM 8-Volt Supply
  14. PCM CMP Sensor Signal
  15. CMP Sensor

Ignition coil primary circuits are monitored with battery voltage more than 8.0 volts during engine cranking or more than 13.0 volts with engine running at less than 3000 RPM, and no coil in dwell during test. DTC will set when PCM senses peak current is not achieved with battery based dwell plus 1.5 milliseconds of diagnostic offset. DTC takes less than 3 seconds to set with engine cranking, or up to 6 seconds with engine running.

  1. Ignition Coil
  2. Intermittent Condition
  3. Automatic Shutdown (ASD) Relay Output Circuit
  4. Ignition Coil Driver Circuit Open
  5. Ignition Coil Driver Circuit Shorted To Ground
  6. PCM

Catalytic converter efficiency is monitored after engine warms up to 158°F (70°C), throttle has been open for 180 seconds at a vehicle speed more than 18 MPH and less than 55 MPH, with engine speed at 1200-1700 RPM and Manifold Absolute Pressure (MAP) vacuum 15-21 in. Hg. As catalyst efficiency deteriorates, the switch rate of the 1/2 Oxygen (O2) sensor approaches that of the 1/1 O2 sensor. DTC will set when PCM senses at any point during the test that the switch ratio reaches a predetermined value. A counter is incremented by one.

  1. Intermittent Condition
  2. Visually Inspect Catalytic Converter
  3. Exhaust Leak
  4. Engine Mechanical Condition
  5. Aging O2 Sensor
  6. Catalytic Converter

Evaporative Emissions (EVAP) purge flow is monitored with engine temperature more than 160°F (71°C), fuel control in closed loop, engine idling for 200 seconds, no low fuel, Manifold Absolute Pressure (MAP) less than 23.6 in. Hg and barometric altitude below 8000 feet. DTC will set when if after having passed the Leak Detection Pump (LDP) test, no air flow through the EVAP system is detected by the EVAP monitor.

  1. Intermittent Condition
  2. EVAP Purge Solenoid Leaks/Stuck Open
  3. EVAP Purge Solenoid Stuck Closed
  4. EVAP Purge Solenoid Vacuum Supply
  5. EVAP Purge Hose Solenoid-To-Canister
  6. EVAP Purge Hose Canister-To-Fuel Tank
  7. EVAP Canister

EVAP leak monitor is monitored immediately after a cold start, with engine coolant temperature within 20°F (-12°C) of ambient temperature, and ambient temperature 40-90°F (4.4-32.2°C) for DTC P0442 and P0455 or 40-86°F (4-30°C) for DTC P0456. DTC P0442 will set when there is a leak larger than 0.040" (1.02 mm) but smaller than 0.080" (2.03 mm) in the EVAP system. DTC P0455 will set when there is a leak larger than 0.080" (2.03 mm) in the EVAP system. DTC P0456 will set when there is a leak larger than 0.020" (0.50 mm) but smaller than 0.040" (1.02 mm) in the EVAP system.

  1. EVAP Emission Leak Detection
  2. EVAP Purge Solenoid Leaks/Stuck Open
  3. Intermittent Leak Detection Pump (LDP) Monitor Failure

Evaporative Emissions (EVAP) purge solenoid circuit is monitored when ignition is on or engine is running, and battery voltage is more than 10.0 volts. DTC will set if actual state of EVAP purge solenoid does not match the intended state when requested to operate by PCM.

  1. Intermittent Condition
  2. EVAP Purge Solenoid Control Circuit Open
  3. EVAP Purge Solenoid Control Circuit Shorted To Ground
  4. EVAP Purge Solenoid Sense Circuit Open
  5. EVAP Purge Solenoid Sense Circuit Shorted To Ground
  6. EVAP Purge Solenoid Leaks/Stuck Open
  7. EVAP Purge Solenoid Stuck Closed
  8. EVAP Purge Solenoid
  9. PCM

Fuel level Test No. 1 is monitored with the ignition on. The fuel level is compared to the previous key down after a 20 second delay. In Test No. 2, PCM monitors the fuel level at ignition on. DTC will set when PCM does not see a difference in fuel level of more than 0.1 volt during Test No. 1, or if PCM does not see a change in the fuel level of .1765 volt over a set amount of miles.

  1. Intermittent Condition
  2. Fuel Tank Damage
  3. Fuel Level Sensor Signal Circuit Shorted To Ground
  4. Fuel Level Sensor Signal Circuit Open
  5. Ground Circuit Open
  6. Fuel Level Sensor

Fuel level sending unit voltage is monitored with ignition on and battery voltage more than 10.4 volts. DTCP0462 will set when fuel level sending unit signal voltage goes to less than 0.4 volt for more than 90 seconds. DTCP0463 will set when fuel level sending unit signal voltage goes to more than 9.9 volts for more than 90 seconds.

  1. Good Trip Equal To Zero
  2. Intermittent Condition

Vehicle Speed Sensor (VSS) signal is monitored with engine running, transaxle not in Park or Neutral, brakes not applied and engine speed more than 1500 RPM. DTC will set when PCM does not receive a VSS signal from Transmission Control Module (TCM) for more than 11 seconds. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. VSS Signal Circuit Shorted To Voltage
  3. VSS Signal From TCM
  4. VSS Signal Circuit Shorted To Ground
  5. VSS Signal Open
  6. PCM VSS Signal

Vehicle Speed Sensor (VSS) signal is monitored with engine running, transaxle not in Park or Neutral and engine speed more than 1500 RPM. DTC will set when PCM does not receive a VSS signal for more than 11 seconds. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. 8-Volt Supply Circuit Open
  3. VSS Signal Circuit Shorted To Ground
  4. VSS Signal Open
  5. PCM VSS Signal
  6. Sensor Ground Circuit Open
  7. VSS

Idle Air Control (IAC) motor sense circuit is monitored when engine is running and battery voltage is more than 10.0 volts. DTC will set when IAC motor sense current is less than 146.33 milliamps.

  1. Intermittent Condition
  2. IAC Motor
  3. IAC Motor Driver Circuit Shorted To Ground
  4. IAC Motor Driver Circuit Open
  5. IAC Motor Sense Circuit Shorted To Ground
  6. IAC Motor Sense Circuit Open
  7. PCM

Idle Air Control (IAC) motor sense circuit is monitored when engine is running and battery voltage is more than 10.0 volts. DTC will set when IAC motor sense current is more than 999 milliamps.

  1. Intermittent Condition
  2. IAC Motor
  3. IAC Motor Sense Circuit Shorted To IAC Motor Driver Circuit
  4. IAC Motor Sense Circuit Shorted To Voltage
  5. IAC Motor Driver Circuit Shorted To Voltage
  6. PCM

Monitored and set conditions information is not available from manufacturer.

  1. Incorrect Vehicle Identification Number (VIN) in Powertrain Control Module (PCM)
  2. Invalid Sentry Key Immobilizer Module (SKIM) Key Not Present
  3. No Communication With SKIM
  4. No VIN Programmed In The PCM
  5. PCM
  6. SKIM DTC SET

DTC P0600 and DTC P0601 are monitored with ignition key on. DTC P0600 will set when an internal bus communication failure occurs between processors. DTC P0601 will set when an internal Checksum for software fails or does not match a calculated value.

  1. PCM Internal Or Serial Peripheral Interface (SPI) Failure

Brake switch sense circuit is monitored with engine running. Test No. 1 is performed when vehicle speed is more than 17 MPH to enable. Test No. 2 is performed when vehicle is stopped and brake switch indicates ON. DTC will set when Test No. 1 senses speed go to zero MPH with no brake input. Condition must be repeated 9 times to set DTC. DTC will also set when Test No. 2 senses vehicle speed go to more than 17 MPH for more than 6.4 seconds without a change in brake state 9 times. Condition must be repeated 9 times to set DTC. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. Fused B+ Circuit
  3. Brake Switch Sense Circuit Shorted To Voltage
  4. Brake Switch Sense Circuit Shorted To Ground
  5. Brake Switch Sense Circuit Open
  6. Ground Circuit Open
  7. Brakelight Switch Operation
  8. PCM

Clutch released switch circuit is monitored during crank or when engine speed is 1500-2880 RPM and vehicle speed is more than 25 MPH. DTC will set when a short to ground is detected during start-up, or an open circuit is detected when engine speed is between 1500-2880 RPM, vehicle speed is more than 25 MPH, and Delta throttle is more than 1.1 volts for 4 seconds. This cycle must repeat 5 times per trip. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. Clutch Pedal Position (CPP) Switch
  3. Clutch Upstop Signal Circuit Open
  4. Clutch Upstop Signal Circuit Shorted To Ground
  5. Ground Circuit
  6. PCM

Inlet Air Temperature (IAT) sensor circuit is monitored with the ignition on and battery voltage more than 10.4 volts. DTC will set when IAT sensor circuit voltage at the PCM goes to less than 0.8 volt.

  1. Intermittent Condition
  2. IAT Sensor Internal Failure
  3. IAT Sensor Signal Circuit Shorted To Ground
  4. IAT Sensor Signal Circuit Shorted To Sensor Ground Circuit
  5. PCM

Inlet Air Temperature (IAT) sensor circuit is monitored with the ignition on and battery voltage more than 10.4 volts. DTC will set when IAT sensor circuit voltage at the PCM goes to more than 4.9 volts.

  1. Intermittent Condition
  2. IAT Sensor Signal Circuit Shorted To Battery Voltage
  3. IAT Sensor Internal Failure
  4. IAT Sensor Signal Circuit Open
  5. Sensor Ground Circuit Open
  6. PCM

1/1 Oxygen (O2) sensor circuit is monitored with engine running, coolant temperature more than 158°F (70°C), open throttle, steady to slightly increasing vehicle speed more than 18 MPH but less than 55 MPH, with a light load on the engine for at least 5 minutes. DTC will set when PCM senses O2 sensor is switching from less than 0.39 volt to more than 0.6 volt and back fewer times than required.

  1. Intermittent Condition
  2. Exhaust Leak
  3. O2 Sensor Signal Circuit Voltage Drop
  4. O2 Sensor Ground Circuit Voltage Drop
  5. O2 Sensor

Engine coolant temperature is monitored when engine is running. DTC will set when engine does not warm to 160°F (71°C) after driving more than 20 MPH for 27 minutes after start.

  1. Cooling System Problem

Fuel pump relay control circuit is monitored with the ignition on and battery voltage more than 10.4 volts. DTC will set when PCM senses an open or shorted condition in the fuel pump relay control circuit.

  1. Fuel Pump Relay Intermittent Operation
  2. Intermittent Condition
  3. Fused Ignition Switch Output Circuit
  4. Fuel Pump Relay Resistance
  5. Fuel Pump Relay Control Circuit Open
  6. Fuel Pump Relay Control Circuit Shorted To Ground
  7. PCM

Manifold Tune Valve (MTV) control circuit is monitored with ignition on, Automatic Shutdown (ASD) relay energized and battery voltage more than 10.0 volts. DTC will set when the PCM senses the MTV is not at the desired state.

  1. Intermittent Condition
  2. Ground Circuit Open
  3. MTV Relay Output Circuit Open
  4. Fused B+ Circuit
  5. ASD Relay Output Circuit
  6. MTV Relay Control Circuit Shorted To Ground
  7. MTV Relay
  8. MTV Relay Control Circuit Open
  9. MTV Solenoid
  10. PCM

Target idle is monitored with the engine idling and the transmission in Drive (if A/T), and no Manifold Absolute Pressure (MAP) or Throttle Position (TP) sensor DTCs present. DTC will set when PCM senses engine idle speed is within 200 RPM above or 100 RPM below the target idle for 15 seconds. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. Idle Air Control (IAC) Motor Passages
  3. Vacuum Leaks
  4. Air Induction System
  5. Throttle Body & Throttle Linkage

Manifold Absolute Pressure (MAP) is monitored with engine speed plus or minus 64 RPM of target idle speed with throttle plate closed. DTC will set when PCM senses too small of a difference between barometric pressure and manifold vacuum with engine running for 8.8 seconds.

  1. Intermittent Condition
  2. 5-Volt Supply Circuit Shorted To Ground
  3. 5-Volt Supply Circuit Open
  4. MAP Sensor Internal Failure
  5. MAP Sensor Signal Circuit Shorted To Ground
  6. MAP Sensor Signal Circuit Shorted To Sensor Ground Circuit
  7. MAP 5-Volt Supply Circuit Open
  8. MAP Sensor Vacuum Port
  9. MAP Sensor
  10. PCM 5-Volt Supply Circuit
  11. PCM MAP Sensor Signal

Manifold Absolute Pressure (MAP) sensor and Throttle Position (TP) sensor signals are monitored with engine running. DTC will set when PCM senses MAP sensor signal does not correlate to TP sensor signal.

  1. Vacuum Leak
  2. Intermittent Condition
  3. TP Sensor Sweep
  4. MAP Sensor Operation
  5. TP Sensor Fully Seated

Auto Shutdown (ASD) relay control circuit is monitored with ignition on and battery voltage more than 10.4 volts. DTC will set when PCM senses an open or short condition in the ASD relay control circuit.

  1. ASD Relay Intermittent Operation
  2. Intermittent Condition
  3. Fused B+ Circuit
  4. ASD Relay Resistance
  5. ASD Relay Control Circuit Open
  6. ASD Relay Control Circuit Short To Ground
  7. PCM

Automatic Shutdown (ASD) relay circuit is monitored with ignition on and battery voltage more than 10.0 volts. DTC will set when no voltage is sensed at PCM when ASD relay is energized.

  1. Intermittent Condition
  2. ASD Relay
  3. Fused B+ Circuit
  4. ASD Relay Output Circuit Open
  5. PCM No-Start
  6. PCM Start

When the engine is running, every 44 milliseconds an inhibit condition is looked for. Inhibit conditions are: wide open throttle, large change in RPM, large change in Manifold Absolute Pressure (MAP), cold engine, insufficient start to run time, or RPM outside of given windows. If an inhibit condition does not exist, the misalignment between the camshaft and the crankshaft is monitored. When the Camshaft Position (CMP) sensor is offset from the Crankshaft Position (CKP) sensor one tooth or more, DTC will set.

  1. Valve Timing Out Of Specification
  2. Valve Timing Not Out Of Specification

Camshaft Position (CMP) sensor and Crankshaft Position (CKP) sensor signals are monitored with engine running or cranking. DTC will set when PCM senses failure counter reaches 20 failures for 2 consecutive trips. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Wiring Harness Inspection
  2. Tone Wheel/Pulse Ring Inspection
  3. Intermittent CKP Sensor Signal
  4. Intermittent CMP Sensor Signal
  5. Intermittent Condition
  6. CKP Sensor
  7. CMP Sensor

Misfire adaptive numerator is monitored under closed throttle deceleration, with A/C off, engine coolant temperature more than 75°F (23.9°C) and more than 50 seconds after engine start. DTC will set when PCM senses one of the Crankshaft Position (CKP) sensor target windows has more than 2.86 percent variance from the reference window.

  1. Intermittent Condition
  2. Tone Wheel/Pulse Ring Inspection
  3. Wiring Harness Inspection
  4. CKP Sensor

Evaporative Emissions (EVAP) system is monitored with battery fully charged, no low fuel, inlet air temperature 40-90°F (4.4-32.2°C), coolant temperature 40-100°F (4.4-37.8°C), and vehicle speed less than 25 MPH. DTC will set if the PCM detects a blocked EVAP hose between the Leak Detection Pump (LDP) and the fuel tank.

  1. Intermittent LDP Monitor Failure
  2. EVAP Canister Obstruction
  3. Pressurizing EVAP System
  4. Obstruction In Hose/Tube Between EVAP Canister And Purge Solenoid
  5. LDP Pressure Hose Obstructed
  6. LDP

Low speed fan control relay circuit is monitored with the ignition on and battery voltage more than 10.0 volts. DTC will set when PCM detects an open or shorted condition in radiator fan relay control circuit.

  1. Low Speed Radiator Fan Relay Intermittent Operation
  2. Intermittent Condition
  3. Fused Ignition Switch Output Circuit
  4. Low Speed Radiator Fan Relay Resistance
  5. Low Speed Radiator Fan Relay Control Circuit Open
  6. Low Speed Radiator Fan Relay Control Circuit Short To Ground
  7. PCM

Leak Detection Pump (LDP) circuit is monitored immediately after a cold start, with ambient temperature 40-90°F (4.4-32.2°C) and engine coolant temperature within 10°F (-12°C) of ambient temperature. DTC will set when PCM does not sense a change in switch state when LDP solenoid is energized.

  1. LDP Vacuum Supply
  2. Wiring Harness Intermittent
  3. LDP
  4. LDP Switch Sense Circuit Shorted To Ground
  5. LDP Switch Sense Circuit Open
  6. PCM

Leak detection Pump (LDP) solenoid circuit is monitored immediately after a cold start, with ambient temperature 40-90°F (4.4-32.2°C) and engine coolant temperature within 10°F (-12°C) of ambient temperature. DTC will set when the state of the LDP solenoid circuit does not match the state desired by the PCM.

  1. Wiring Harness Intermittent
  2. LDP
  3. Fused Ignition Switch Output
  4. LDP Solenoid Control Circuit Shorted To Ground
  5. LDP Solenoid Control Circuit Open
  6. PCM

5-volt supply circuit is monitored with ignition on. DTC will set when PCM senses 5-volt supply to sensors is less than 3.5 volts for 4 seconds.

  1. Intermittent Condition
  2. Throttle Position (TP) Sensor
  3. Manifold Absolute Pressure (MAP) Sensor
  4. A/C High Pressure Switch
  5. 5-Volt Supply Shorted To Ground
  6. PCM

PCM is monitored with ignition on. DTC will set in PCM when PCM is not programmed.

  1. PCM Not Programmed
  2. PCM

DTC P1653 is monitored with the ignition on. DTC will set when the PCM detects a short to ground on the PCI bus for more than 5 seconds.

  1. Intermittent Condition
  2. Internal Controller Short To Ground

DTC P1654 is monitored with the ignition on. DTC will set when the PCM detects a short to voltage on the PCI bus for more than 5 seconds.

  1. Intermittent Condition
  2. Internal Controller Short To Voltage

DTC P1656 is monitored with the ignition on. DTC will set when the PCM determines that the PCI bus is not available for more than 5 seconds.

  1. Intermittent Condition
  2. Open PCI Bus Circuit
  3. PCM

DTC P1685 is monitored with the ignition on. DTC will set when the PCM does not receive a valid key message from the Sentry Key Immobilizer Module (SKIM).

  1. Incorrect Vehicle Identification Number (VIN) In PCM
  2. Invalid SKIM Key Not Present
  3. No Communication With SKIM
  4. No VIN Programmed In The PCM
  5. SKIM DTC Set
  6. PCM

DTC P1686 is monitored with the ignition on. DTC will set when the PCM does not receive a bus message from the Sentry Key Immobilizer Module (SKIM) when expected.

  1. PCM/SKIM
  2. Incorrect Vehicle Identification Number (VIN) In PCM
  3. Intermittent Condition
  4. Loss Of SKIM Communication
  5. PCI Bus Circuit Open From PCM To SKIM

DTC P1687 is monitored with the ignition on. DTC will set when no messages are received from the Mechanical Instrument Cluster (MIC) 20 seconds.

  1. Intermittent Condition
  2. Communication with MIC

DTCs P1696 and P1697 are monitored with the ignition on. DTC will set when an attempt to program/write to the internal Electronically Erasable Programmable Read Only Memory (EEPROM) failed. DTC is also check at power-down.

  1. Compare Serial Peripheral Interface (SRI) Mileage With Odometer
  2. DRBIII(R) Displays Write Failure
  3. DRBIII(R) Displays Write Refused 2nd Time
  4. DRBIII(R) Displays SRI Mileage Invalid

DTC P1698 is monitored only on vehicles equipped with automatic transmission, with the ignition on and battery voltage more than 10.0 volts. DTC will set when no bus messages are received from the Transmission Control Module (TCM) for 20 seconds. This is a 2-trip fault. See TRIP INDICATOR under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.

  1. Intermittent Condition
  2. Communication With TCM
  3. PCM

Note. Park/Neutral (P/N) position may also be referred to as Transmission Range Sensor (TRS).

TRS circuit is monitored when transmission is in Park, Neutral or Drive and PCM is not in limp-in mode. DTC will set if PCM detects an incorrect TRS state for a given mode of vehicle operation.

  1. Intermittent TRS
  2. TRS Sense Circuit Shorted To Ground
  3. TRS Sense Circuit Open
  4. TRS
  5. PCM

More articles — Engine Controls - Self-Diagnostics