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Summary of Monitor Information

ODB II Monitor Operation:




The table summarizes the various OBDII monitors operation.

OBDII MONITOR RUN PROCESS NGC VEHICLES
The following procedure has been established to assist Chrysler Dealer Technicians in the field with enabling and running OBD II Monitors. The order listed in the following procedure is intended to allow the technician to effectively complete each monitor and to set the CARB Readiness Status in the least time possible.

NOTE
C. Once the monitor run process has begun, do not turn off the ignition. By turning the ignition key off, monitor enabling conditions will be lost. NVLD Monitor runs after key off.
D. By performing a Battery Disconnect, or Selecting Erase DTCs, the CARB Readiness and all additional OBD II information will be cleared.

Monitor Preliminary Checks:
4. Plug a DRBIII into the vehicle's DLC.
5. Turn the ignition, KEY ON - ENGINE OFF. Watch for MIL lamp illumination during the bulb check. MIL lamp must have illuminated, if not, repair MIL lamp.
6. On the DRBIII Select # 1 DRBIII Stand alone.
7. Select # 1 1998-2003 Diagnostics
8. Select # 1 Engine
9. Select # 2 DTCs and Related Functions
10. Select # 1 Read DTCs
- Verify that No Emissions Related DTCs are Present.
- If an Emissions DTC is Present, the OBD II Monitors may not run and the CARB Readiness will not update.
- The Emissions related DTC, will need to be repaired, then cleared. By clearing DTCs, the OBD Monitors will need to be run and completed to set the CARB Readiness Status.

11. Return to Engine Select Function Menu and Select # 9, OBD II Monitors.
12. Select # 3 CARB Readiness Status.

Do all the CARB Readiness Status Locations read YES?
- YES, then all monitors have been completed and this vehicle is ready to be I/M or Emission Tested.
- NO, then the following procedure needs to be followed to run/complete all available monitors.

NOTE
A. Only the monitors, which are not YES in the CARB Readiness Status, need to be completed.
B. Specific criteria need to be met for each monitor.
Each monitor has a Pre-Test screen to assist in running the monitor.
For additional information, refer to the Chrysler Corporation Technical Training Workbook titled On Board Diagnostics: OBDII/EOBD.
C. The most efficient order to run the monitors has been outlined below, including suggestions to aid the process.

1.Natural Vacuum Leak Detection with Purge Monitor
This monitor requires a cool down cycle, usually an overnight soak for at least 8 hours without the engine running. The ambient temperature must decrease overnight - parking the vehicle outside is advised. To run this test the fuel level must be between 15-85% full. For the monitor run conditions select the EVAP MON PRE-TEST in the DRBIII, OBD II Monitors Menu The Purge monitor will run if the small leak test reports a pass.

Criteria for NVLD monitor
1. Engine off time greater than one hour
2. Fuel Level between 15% and 85%
3. Start Up ECT and IAT within 10 °C (18 °F).
4. Vehicle started and run until Purge Monitor reports a result.

Note: If the vehicle does not report a result and the conditions where correct. It may take up to two weeks to fail the small leak monitor. DO NOT use this test to attempt to determine a fault. Use the appropriate service information procedure for finding a small leak. If there are no faults and the conditions are correct this test will run and report a pass. Note the Small leak test can find leaks less than 10 thousands of an inch. If a small leak is present it takes approximately one week of normal driving to report a failure.

2.Catalyst / O2 Monitor
With NGC, Catalyst and O2 Monitor information are acquired and processed at the same time. Most vehicles will need to be driven at highway speed (< 50 mph) for a few minutes. Some trucks run the monitor at idle in drive. If the vehicle is equipped with a manual transmission, using 4th gear may assist in meeting the monitor running criteria. For the monitor run conditions, select the BANK 1 CAT MON PRE-TEST in the DRBIII, OBD II Monitors Menu.

3.EGR Monitor
The EGR monitor now runs in a closed throttle decel or at idle on a warm vehicle. However, it is necessary to maintain the TPS, Map and RPM ranges to allow the monitor to complete itself. For the monitor run conditions, select the EGR PRE-TEST in the DRBIII, OBD II Monitors Menu.

4.O2 Sensor Heater Monitor
This monitor is now continuously running once the heaters are energized. Pass information will be processed at power down. For the monitor run conditions, select the O2S HEATER MON PRETEST in the DRBIII, OBD II Monitors Menu.

ECM (CM848) OPERATING MODES (DIESEL)
As input signals to the Engine Control Module (ECM) change, the ECM adjusts its response to output devices. There are several different modes of operation that determine how the ECM responds to the various input signals.

IGNITION SWITCH ON (ENGINE OFF) MODE
When the ignition switch is in the "on" position, the following actions occur:

1. When the PCM and ECM receive an ignition sense input, they power up. Battery voltage is supplied through the battery voltage input.
2. The wait-to start, water-in-fuel, check engine, check gauges, and transmission temperature (auto trans only) lamps are turned on by the PCM, ECM, or BCM for at least 2 seconds as a bulb test. This is done by direct wire or through the Bus to the smart cluster.




3. The ECM monitors the intake air temperature signal. If the intake air temperature is below a predetermined temperature, the ECM will start the air intake preheat cycle. The ECM will energize the intake heaters by grounding the air intake relays. The ECM will turn the wait-to- start lamp on until the preheat cycle is over. If the ECM receives a crank signal before the preheat (Fig 1.) cycle is over, the preheat cycle will be aborted.
4. The ECM will request the water-in-fuel lamp on if a signal is received from the water-in-fuel sensor.

NOTE: If the water-in-fuel lamp remains illuminated after the 2-second bulb check, the vehicle should not be started until the fuel filter has been drained.

ENGINE START-UP MODE
When the ignition key is held in the "start" position, the following occurs:
1. The ECM receives the crank signal input from the camshaft position sensor.
2. The air intake heaters are not energized during cranking.
3. The ECM monitors engine speed and when the engine speed is above 650 rpm, the ECM determines that the engine is running.




4. If the ECM receives a crank signal before the preheat (Fig 2) cycle is over, the heaters will be disabled. However, the post-heat cycle will begin if the engine is in the run state or speed is above 1200 rpm.

ENGINE WARM-UP MODE
1. The ECM may start the air intake heater post- heat cycle depending on intake air temperature. If manifold air temperature was 66 °F or less when the ignition was turned on, the cycle is started.
2. If the transmission temperature sensor shows it is below 59 °F, the automatic transmission will not be allowed to enter overdrive.
3. If the transmission temperature sensor shows it is below 69 °F, the transmission's torque converter clutch will not be allowed to engage.
4. The ECM will request the water-in-fuel lamp on if a signal is received from the water-in-fuel sensor.

CRUISE OR IDLE MODE
During the cruising speed, the following inputs are received by the ECM:
1. The ECM monitors intake manifold air temperature through the intake air temperature sensor.
2. The intake air heater post-heat cycle will be complete, if it is not already over.
3. The vehicle speed, and throttle position sensors are used by the PCM to control the transmission overdrive and torque converter clutch operation.
4. If the transmission temperature sensor shows it is below 59 °F or above 275 °F, the automatic transmission will not be allowed to enter overdrive. If the transmission is in overdrive when the transmission temperature is above 275 °F, the transmission Will downshift and not upshift again until the transmission temperature drops to 240 °F.
5. The water-in-fuel sensor signal is used by the ECM to request the water-in-fuel lamp on, if water is sensed in the fuel.

ACCELERATION MODE
When there is an abrupt demand for increased engine output and vehicle acceleration, the following occurs:
1. The vehicle speed, and throttle position signals are used to control transmission overdrive and torque converter clutch operation.
2. If the transmission temperature sensor shows it is below 59 °F, the torque converter clutch will not be allowed to engage.
3. If the transmission temperature sensor shows it is below 59 °F or above 275 °F, the automatic transmission will not be allowed to enter overdrive. If the transmission is in overdrive when the transmission temperature is above 275 °F, the transmission will downshift and not upshift again until the transmission temperature drops to 240 °F.
4. If the speed control system resume/accelerate function is being used, the ECM (Diesel applications with manual transmission use the CM848 ECM to conduct speed control system) will only allow the vehicle to accelerate at a predetermined rate. If a speed control has been set and the resume/accelerate button is momentarily pushed in, the ECM will increase vehicle speed by two miles per hour.
5. The ECM will disable the speed control when:
- the brakes are applied
- excessive engine speed
- the clutch is disengaged (manual transmission)
- the gear selector is shifted to neutral (automatic transmission)
- the speed control off switch is activated

DECELERATION MODE
During deceleration, the following inputs are received by the ECM:
1. The vehicle speed, crank position, and throttle position signals are used to control transmission overdrive and torque converter clutch operation.
2. The torque converter clutch will disengage, if the brakes are applied.
3. If the transmission temperature sensor shows it is below 59 °F or above 275 °F, the automatic transmission will not be allowed to enter overdrive. If the transmission is in overdrive when the transmission temperature is above 275 °F, the transmission will downshift and not upshift again until the transmission temperature drops to 240 °F.
4. The ECM will disable the speed control when:
- the brakes are applied
- excessive engine speed
- the clutch is disengaged (manual transmission)
- the gear selector is shifted to neutral (automatic transmission)
- the speed control off switch is activated

IGNITION SWITCH OFF MODE
When the ignition switch is turned to the "off" position, the PCM and ECM still stores in memory trouble codes and the throttle position sensor value from the previous key-on.

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