Electronic Control Modules - Service Information: Diagnosis Jeep Compass I рестайлинг 2

DIAGNOSIS AND TESTING - HEATED SEAT MODULE

In order to obtain conclusive testing, the heated seat system and the Local Interface Network (LIN) data bus circuit must be checked. Any diagnosis of the heated seat system should begin with, the use of a scan tool and the appropriate diagnostic Service Information.

Refer to the appropriate wiring information for complete circuit schematic or connector pin-out information.

Note. Vehicles equipped with the heated seat option utilize a low voltage cut-off feature. This feature turns off power to the heated seat system anytime vehicle voltage is below 11.7v or above 15.5v. Be certain to check the vehicle electrical system for proper voltage anytime the power seat system appears inoperative.

Before any testing of the heated seat system is attempted, the battery should be fully-charged.

Scheme 4

1. Position the left front seat to the full rearward position.
2. Disconnect and isolate the battery negative cable.
3. Disconnect the wire harness connector (4) from the heated seat module (3).
4. Unsnap the heated seat module retaining tab (2) from the seat pan (1).
5. Remove the heated seat module (3) from the vehicle.

DIAGNOSTIC TROUBLE CODES

Each diagnostic trouble code (DTC) is diagnosed by following a specific procedure. The diagnostic test procedure contains step-by-step instruction for determining the cause of the DTC as well as no trouble code problems. For more information, refer to the appropriate Diesel Powertrain Diagnostic Information .

PCM DIAGNOSTIC TROUBLE CODES

Note. Before replacing the 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 failures to components (i.e. relays and solenoids) and shorted circuits (i.e. sensor pull-ups, drivers and ground circuits). These faults are difficult to detect when a double fault has occurred and only one DTC has set. If the scan tool displays faults for multiple components (i.e.VSS, ECT, Batt Temp, etc.) identify and check the shared circuits for possible problems before continuing (i.e. sensor grounds or 5-volt supply circuits). Refer to the appropriate wiring diagrams to identify shared circuits. For more information, refer to the appropriate Diesel Powertrain Diagnostic Information .

Scheme 5

The PCM receives input signals from various switches and sensors that are referred to as PCM Inputs. Based on these inputs, the PCM adjusts various engine and vehicle operations through devices that are referred to as PCM Outputs.

Note. PCM Inputs

1. Air Conditioning Controls
2. Battery Voltage
3. Brake Switch
4. Camshaft Position Sensor
5. Clutch Upstop Switch
6. Clutch Interlock
7. Crankshaft Position Sensor
8. Engine Coolant Temperature Sensor
9. Fuel Level Sensor (Bus message)
10. Ignition Switch
11. Intake Air Temperature Sensor
12. Knock Sensor
13. Evaporative System Integrity Monitor
14. Manifold Absolute Pressure (MAP) Sensor
15. Oil Pressure Switch
16. Oxygen Sensors
17. Power Steering Pressure Switch
18. Speed Control Switches
19. Vehicle Speed Sensor (MTX-equipped models)

Note. PCM Outputs

1. Air Conditioning Clutch Relay
2. Charging Indicator Lamp (Bus Message)
3. Proportional Purge Solenoid
4. Fuel Injectors
5. Generator Field
6. Ignition Coils
7. Malfunction Indicator (Check Engine) Lamp (Bus Message)
8. Manifold Flow Valve
9. Oxygen Sensors Heater Controls
10. Variable Valve Timing
11. Vehicle Speed (Manual Transmission)

Based on inputs it receives, the PCM adjusts fuel injector pulse width, idle speed, ignition spark advance, ignition coil dwell and EVAP canister purge operation. The PCM also determines the appropriate transmission shift schedule and shift points, depending on the present operating conditions and driver demand. The PCM regulates the cooling fan, air conditioning and speed control systems. The PCM changes generator charge rate by adjusting the generator field. The PCM also performs diagnostics.

The PCM adjusts injector pulse width (air-fuel ratio) based on the following inputs.

1. Battery voltage
2. Coolant temperature
3. Exhaust gas content (oxygen sensor)
4. Engine speed (crankshaft position sensor)
5. Intake air temperature
6. Manifold absolute pressure
7. Throttle position

The PCM adjusts ignition timing based on the following inputs.

1. Coolant temperature
2. Engine speed (crankshaft position sensor)
3. Knock sensor
4. Manifold absolute pressure
5. Throttle position
6. Transmission gear selection (park/neutral switch)
7. Intake air temperature

The PCM also adjusts engine idle speed through the idle air control motor based on the following inputs.

1. Air conditioning sense
2. Battery voltage
3. Brake switch
4. Coolant temperature
5. Engine speed (crankshaft position sensor)
6. Engine run time
7. Manifold absolute pressure
8. Power steering pressure switch
9. Throttle position
10. Transmission gear selection (park/neutral switch)
11. Vehicle distance (speed)

The camshaft position sensor and crankshaft position sensor signals are sent to the PCM. If the PCM does not receive the signal within approximately 1 second of engine cranking, it deactivates the fuel pump. When these are deactivated, power is shut off to the fuel injectors, ignition coils, oxygen sensor heating elements and fuel pump.

The PCM contains a voltage converter that changes battery voltage to a regulated 5 volts direct current to power the camshaft position sensor, crankshaft position sensor, manifold absolute pressure sensor, throttle position sensor, A/C pressure switch, A/C pressure transducer, and vehicle speed sensor.

OBTAINING DTC'S USING SCAN TOOL

1. Connect the scan tool to the data link (diagnostic) connector. This connector is located in the passenger compartment; at the lower edge of instrument panel; near the steering column.
2. Turn the ignition switch on and access the "Read Fault" screen.
3. Record all the DTC's and "freeze frame" information shown on the scan tool.
4. To erase DTC's, use the "Erase Trouble Code" data screen on the scan tool. Do not erase any DTC's until problems have been investigated and repairs have been performed.

DIAGNOSIS AND TESTING - STEERING COLUMN MODULE

The hard wired circuits between components related to the Steering Control Module (SCM) may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the SCM or the electronic controls and communication between modules and other devices that provide some features of the SCM. The most reliable, efficient and accurate means to diagnose the SCM or the electronic controls and communication related to SCM operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

Scheme 6

The transmission control module (TCM) (3) is inside the car, behind the instrument panel to the right of the left kick panel (1) where the clutch pedal would be located. New controllers are shipped with generic software but need to be initialized for the vehicle into which it is installed. Refer to MODULE, TRANSMISSION CONTROL, STANDARD PROCEDURE .

Scheme 7

In order to select the gear ratio which can obtain the driving force in accordance with driver's intention and the vehicle condition, TCM monitors the driving conditions, such as the vehicle speed and the throttle position and selects the optimum gear ratio, and determines the gear change steps to the gear ratio. Then it sends the command to the stepping motor, and controls the flow-in/flow-out of line pressure to/from the primary pulley to determine the position of the moving-pulley and control the gear ratio.

Scheme 8

Selection of the gear ratio is set for every position separately.