Engine Controls Self-Diagnostics: Other Chrysler Concorde II

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. Engine Misfire Monitor
2. Fuel System Monitor
3. Oxygen Sensor Monitor
4. Oxygen Sensor Heater Monitor
5. Catalyst Monitor
6. EVAP System Leak Detection Pump Monitor
7. EGR 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 (80 for fuel system monitor or misfire monitor) 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. Excessive Oil Consumption
3. Exhaust System
4. Fuel Injector Mechanical Faults
5. Fuel Pressure
6. PCM Connector Engagement
7. PCM System Ground
8. Throttle Body Airflow
9. Vacuum Assist

Trip Indicator

The trip is essential for running monitors and turning off the Malfunction Indicator Light (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 global good trip, fuel system good trip and misfire good trip.

1. Global Good Trip To count as a good trip, oxygen sensor monitor and catalyst efficiency monitor must run and pass.
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® scan tool. Warm-up cycles are used to clear DTCs and freeze frame data from PCM memory. Forty warm-up cycles (80 for fuel system monitor or misfire monitor) 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°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® scan tool. 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.

Hard Failures

Hard failures cause Malfunction Indicator Light (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 Diagnostic Trouble Codes (DTC). 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 Malfunction Indicator Light (MIL) to flicker or illuminate and go out after intermittent failure goes away. However, the corresponding Diagnostic Trouble Code (DTC) will be retained in Powertrain Control Module (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 - GASOLINE article.

SERVICE PRECAUTIONS

Before proceeding with diagnosis, the following precautions must be followed

1. Ensure fuel pressure is released before disconnecting fuel lines or fittings, as fuel system is under pressure and may cause personal injury. See «FUEL SYSTEM PRESSURE RELEASE»(ref-4768-S20490479472000072400000) .
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 if necessary. Always perform indicated verification procedure after repairs are made.
3. DO NOT use 12-volt test light when checking 5-volt or 8-volt supply circuit, CCD bus circuit, camshaft position sensor signal circuit, crankshaft position sensor signal circuit, oxygen sensor signal circuit or vehicle speed sensor signal circuit or Powertrain Control Module (PCM) may be damaged.
4. When using a jumper wire, ensure either jumper wire or circuit is fuse-protected.
5. Before disconnecting connector from any control module, ensure ignition is off before removing connector.
6. When checking voltage or continuity at any control module, probe connector for control module from pin side. DO NOT backprobe connector or probe wires through the insulation unless specifically directed to do so.
7. DO NOT cause short circuits when performing electrical tests. This will set additional Diagnostic Trouble Codes (DTC), making diagnosis of original problem more difficult.
8. Use specified test equipment when performing electrical tests.

POWERTRAIN CONTROL MODULE

Note. If replacing Powertrain Control Module (PCM), the correct vehicle mileage and Vehicle Identification Number (VIN) must be programmed into PCM to prevent Diagnostic Trouble Codes (DTC) from being stored in Anti-Lock Brake System (ABS) module and Air Bag Control Module (ACM). If replacing PCM on models equipped with a Sentry Key Immobilizer Module (SKIM), the secret key data must also be updated to enable engine starting.

Programming Powertrain Control Module

1. Connect scan tool to Data Link Connector (DLC), located under left side of instrument panel. see scheme 1 Ensure shift selector is in Park or Neutral. Turn ignition on. Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from ABS module and ACM. If equipped with Sentry Key Immobilizer Module (SKIM), go to next step. If not equipped with SKIM, programming is complete.
2. Using scan tool, select THEFT ALARM, SKIM and then MISCELLANEOUS. Select PCM REPLACED. Place the SKIM in SECURED ACCESS MODE by entering the appropriate Personal Identification Number (PIN) for this vehicle. PIN may be obtained from the owner, vehicle's invoice, or from the manufacturer. Press ENTER to transfer secret key data from SKIM to the PCM. This will enable the vehicle to start.
3. If 3 attempts are made to enter the SECURED ACCESS MODE by using an incorrect PIN, the SECURED ACCESS MODE will be locked out for one hour. To exit lock out mode, leave ignition on with all accessories turned off. After one hour, enter correct PIN. It may be necessary to monitor battery voltage and connect a battery charger.

TRANSMISSION CONTROL MODULE

Connect scan tool to Data Link Connector (DLC). Start engine and let idle. Press and hold brake pedal down. Using scan tool, select TRANSMISSION, MISCELLANEOUS, then QUICK LEARN PROCEDURE. Follow steps displayed on scan tool to complete quick learn procedure.

FUEL SYSTEM PRESSURE RELEASE

1. Locate Power Distribution Center (PDC) on left side of engine compartment. see scheme 2 Remove fuel pump relay from PDC. (Scheme 33)
2. Start engine and allow engine to idle until engine stalls. Attempt to restart engine until engine will no longer run. Turn ignition off. 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.
3. Diagnostic Trouble Code (DTC) may have been stored in Powertrain Control Module (PCM) due to the removal of fuel pump relay. Using scan tool, clear DTCs from PCM.

Scheme 33