Engine Controls - Diagnostic Methods -- e-350 6.0l Diesel Models Ford Cutaway E350 Super Duty

Overview

The Diagnostic Methods section provides detailed instructions on how to access or carry out routine diagnostic tasks. This section can be referenced as many times as needed for step-by-step instructions for routine procedures.

Required Equipment

1. Adapter Cable, ICP/EBC 418-D003 (D94T-50-A) or equivalent
2. Adapter, Compression Test 303-757 or equivalent
3. Adapter, Fuel Pressure Test 310-111 or equivalent
4. Adapter, High Pressure Pump Test 303-765 or equivalent
5. Adapter, High Pressure Rail Test 303-766 or equivalent
6. Adapter, ICP Test 303-1163 or equivalent
7. Adapter Set, Oil High Pressure Leakage 303-1071 or equivalent
8. Diesel Fuel Flow Tester 310-193 or equivalent
9. Disconnect Tool, Quick Release Coupling 303-755 or equivalent
10. DSL ENG Pressure Test Kit 014-00761 or equivalent
11. Digital Multimeter (DMM) FLU77-4 or equivalent.
12. Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool with functionality described under Scan Tool Setup and Functionality
13. Tool, Vane Position Sensor Cable Kit 418-626 or equivalent

Optional Equipment

Note. Refer to equipment user manual for details on tool accessories and function.

1. R134A Manifold Gauge Set 176-R932A or equivalent
2. Non-powered test lamp
3. Vacuum/Pressure Tester 164-R0253 or equivalent. Range 0-101.3 kPa (0-30 in-Hg.) Resolution 3.4 kPa (1 in-Hg.)
4. Instrument Gauge System Tester 014-R1063 or equivalent.

Scan Tool Setup and Functionality

Connect the scan tool to the data link connector (DLC) for communication with the vehicle.

The DLC is located in the drivers side compartment. It is attached to the instrument panel under the steering column and accessible from the driver seat.

The DLC is rectangular in design and capable of accommodating up to 16 terminals. The connector has keying features to allow easy connection.

The required scan tool functions are described below

1. monitor, record, and playback of parameter identification (PID)s
2. freeze frame PID data
3. diagnostic test modes; self-test, clear diagnostic trouble codes (DTCs)
4. output test mode
5. resetting keep alive memory (KAM)
6. diagnostic monitoring test results (mode 6) for on board diagnostic (OBD) on board monitors
7. on board system readiness (OBD monitor completion status)

Some of these functions are described. Refer to the scan tool manufacturer's manual for specific information on the scan tool setup, operation, and specific cables and adapters required.

Communication Error

It is possible to get a test fail error from a scan tool when initiating a test or viewing PIDs. The communication error could be caused by operator error, the vehicle wiring or connectors, or the powertrain control module (PCM) and other control modules connected to the DLC wiring. The PCM responds to a scan tool whenever the scan tool requests a test. Some are normal responses to valid requests. The others are communication error responses. If the scan tool displays any of the test fail error responses, reinitialize the scan tool. If the error is still present, GO to PINPOINT TEST AE , after checking the scan tool connections, cable/adapters, and entry of vehicle information. Verify the power take-off system or auxiliary idle control (if equipped) is off when trying to carry out the self-tests.

Visual Checks

Note. Before carrying out the Quick Test, always carry out the necessary visual checks and safety precautions listed below.

1. Inspect the air cleaner and the inlet ducting.
2. Check the system wiring harness for correct connections, bent or broken pins, corrosion, loose wires, and correct routing.
3. Check the powertrain control module (PCM), sensors, and actuators for physical damage.
4. Check the engine coolant for correct level and mixture.
5. Check the transmission fluid level and quality.
6. Make all necessary repairs before continuing with the Quick Test.

Vehicle Preparation

1. Carry out all of the safety steps required to start and run the vehicle tests. Apply the parking brake, place the gear selector lever firmly into the PARK position (NEUTRAL on manual transmission), and block the drive wheels.
2. Turn off all electrical loads, such as radios, lights, A/C, blower and fans.
3. Start the engine and bring it up to normal operating temperature.

Quick Test Description

The Quick Test is carried out by retrieving the key ON engine OFF (KOEO), key ON engine running (KOER), and continuous memory diagnostic trouble codes (DTCs).

Quick Test is divided into 5 specialized tests

1. Retrieve/Clear Continuous DTCs
2. KOEO On-Demand Self-Test
3. KOEO Injector Electrical Self-Test
4. KOER On-Demand Self-Test
5. KOER Glow Plug Monitoring Self-Test

All are described below.

Quick Test checks the integrity and function of the powertrain control module (PCM) and outputs the test results upon demand. The Quick Test also provides a quick end check of the powertrain control system and is usually carried out at the start of each diagnostic procedure. It is also carried out at the end of the pinpoint tests for verification of repair and to make sure no other concerns were incurred while repairing a previous concern.

Retrieve/Clear Continuous Diagnostic Trouble Codes (DTCs)

Retrieve/clear continuous DTCs is a functional test of the PCM. DTCs can be retrieved or cleared with the ignition ON and the engine OFF or running. Unlike the KOEO and KOER self-tests, which can only be activated on demand, the continuous monitor is always active in monitoring the system. When a concern is detected, a DTC is stored in memory to be retrieved at a later date, making it possible to diagnose intermittent concerns. DTC P1000 may be the only DTC displayed, indicating an incomplete on board diagnostic (OBD) drive cycle (more drive time needed). The fuel injection control module (FICM) continuously monitors the injector circuits for a concern. The FICM sends failure information through the controller area network (CAN) and a PCM DTC is set.

Quick Test

For all concerns, refer to the SYMPTOM CHARTS . The Quick Test is carried out by retrieving KOEO, KOER, and continuous memory DTCs. If a DTC is retrieved, you must then go to the . If unable to complete the self-test, GO to PINPOINT TEST AE .

Key On Engine Off (KOEO) On-Demand Self-Test

Note. It is necessary to wait 4 seconds after ignition ON to initiate the KOEO self-test. Failure to do so results in a test fail PCM message to be displayed.

The engine may run rough during this test.

The KOEO on-demand self-test is an on-demand functional test of the PCM carried out with the ignition ON and the engine OFF. This test checks that all inputs and outputs (circuits, sensors, regulators, relays, and solenoids) connected to the PCM are electrically operating without a concern.

Key On Engine Off (KOEO) Injector Electrical Self-Test

Note. If no DTCs are present refer to PERFORMANCE DIAGNOSTIC PROCEDURES and carry out the Power Balance test 6b. If the KOEO injector electrical self-test aborts while trying to activate, refer to INJECTOR INTERRUPT FOR ENHANCED DIAGNOSTICS .

The KOEO injector electrical self-test is an on-demand functional test of the FICM carried out with the ignition ON and the engine OFF. This test determines if the injector circuits and coils are correctly operating. If a concern is detected by the FICM, a CAN message is sent to the PCM. Corresponding DTCs are displayed at the end of the self-test.

1. Turn off all accessories. If the vehicle is equipped with a power take-off (PTO) system or auxiliary idle control, it must be turned off to carry out self-tests.
2. Carry out the necessary vehicle preparation and a visual inspection. Refer to Quick Test Operation .
3. Refer to the scan tool operating manual for instructions.
4. Ignition ON, engine OFF.
5. Carry out the KOEO Injector Electrical Self Test.
6. Ignition in OFF position.
7. Record the DTCs and carry out the appropriate pinpoint test.

Scheme 184

Key On Engine Running (KOER) On-Demand Self-Test

The KOER on-demand self-test is an on-demand functional test of the PCM carried out with the engine running. Temperature is not a factor, but the air conditioning (A/C) must be turned off. A check is made on the injection control pressure (ICP), variable geometry turbocharger (VGT), and exhaust gas recirculation (EGR) systems. During this test, the engine RPM may vary. A concern must be present at the time of testing for the KOER on demand self-test to detect a concern. If a concern is detected, a DTC is output on the data link at the end of the test when requested by a scan tool. Only a hard concern code DTC is displayed.

Key On Engine Running (KOER) Glow Plug Monitoring Self-Test

Note. When running this self-test, the battery voltage must not decrease to less than 10 volts or exceed 14 volts. Make sure that the batteries are OK and the charging system is working correctly. If necessary, apply the accelerator pedal to maintain system voltage.

The KOER glow plug monitoring self-test is an on-demand functional test of the glow plug system carried out with the engine running and the A/C off. Battery voltage must be maintained at 10-14 volts during this test. If necessary, apply the accelerator pedal to increase voltage to the specified level. The PCM activates the glow plug control module and monitors the glow plug circuits. A concern must be present at the time of testing for the test to detect a concern. DTCs are sent to the PCM on the diagnostic line and then output to the scan tool.

Malfunction Indicator Lamp (MIL) DTCs

MIL DTCs are generated to alert the driver that there is a concern with the system or the vehicle is in failure management effects mode (FMEM). MIL DTCs are also used to indicate an emission concern. Non-MIL DTCs indicate a less serious or non-emission related concern with the system.

Clear The Continuous Diagnostic Trouble Codes (DTCs) And Reset The Emission Monitors Information in The Powertrain Control Module (PCM)

The clearing of continuous DTCs allows the scan tool to command the PCM to clear/reset all emission-related diagnostic information. While carrying out this operation, DTC P1000 is stored in the PCM until all the OBD system monitors or components have been tested to satisfy a drive cycle without any other concerns occurring. For additional information about a drive cycle, refer to On-Board Diagnostic (OBD) DRIVE CYCLE . Clearing the DTCs from the vehicle-specific continuous memory DTC menu clears all systems, including the OBD systems. Clearing the DTCs from the OBD generic menu only clears OBD features.

Description

The following events occur when the continuous DTCs and emission monitors information is cleared from the PCM

1. Clears the number of DTCs.
2. Clears the DTCs.
3. Clears the freeze frame data.
4. Resets the status of the OBD system monitors.
5. Sets DTC P1000 as a vehicle-specific DTC. DTC P1000 does not appear as an OBD DTC.

Refer to the manufacturer's manual for scan tool instructions.

Resetting the KAM returns the powertrain control module (PCM) memory to its default setting. Adaptive learning contents such as idle speed and refueling event are included. To clear continuous diagnostic trouble codes (DTCs) in the PCM and have it reset the emissions monitors information is also part of a KAM reset. Refer to CLEAR THE CONTINUOUS DIAGNOSTIC TROUBLE CODES (DTCS) AND RESET THE EMISSION MONITORS INFORMATION IN THE POWERTRAIN CONTROL MODULE (PCM ). Both can be useful in post repair retest.

After the KAM has been reset, the vehicle may exhibit certain driveability concerns. It is necessary to drive the vehicle to allow the PCM to relearn the values for optimum driveability and performance.

This function may not be supported by all scan tools. Refer to the scan tool manufacturer's instruction manual .

If an error message is received or the scan tool does not support this function, disconnecting the battery ground cable for a minimum of 5 minutes may be used as an alternative procedure.

After the KAM has been reset, DTC P1000 is stored in the PCM. If the battery ground cable was disconnected to reset the KAM, DTCs P0603 or P1603 are also present.

All on board diagnostic (OBD) scan tools should display the OSR Test. The OSR displays the supported monitors on the vehicle, the status of all monitors (complete or not complete), and the malfunction indicator lamp (MIL) status. If a monitor is not complete, the scan tool does not identify the monitor that has not completed. Readiness is reported based on the completeness of the comprehensive component monitors (CCM) and the misfire monitor and the exhaust gas recirculation (EGR) monitor. These monitors must be complete before readiness can be cleared.

Accessing On Board System Readiness (OSR) Test

Refer to the manufacturer's manual for scan tool instructions.

On Board Diagnostic (OBD) PID Data Monitor

The PID monitor for OBD offers real time evaluation of several emissions-related parameters. Most of these are related to the HO2S, for which the diesel has no equivalent. The only parameters which apply are DTC CNT, IAT, LOAD, MAP, MIL, RPM, and VSS.

Accessing the PID Data Monitor

Refer to the manufacturer's manual for scan tool instructions.

On Board Diagnostic (OBD) Pending Diagnostic Trouble Codes (DTCs)

Pending DTCs are DTCs that have only set during one drive cycle and may not have set the malfunction indicator lamp (MIL) yet. These DTCs may be identified using the retrieve pending DTCs feature. Additionally, they are found in the vehicle-specific mode retrieve/clear continuous memory DTCs from the instant that the DTC is set.

This function only reports pending concerns that have occurred during the present drive cycle, but does not indicate single concerns that occurred on any previous drive cycle.

Refer to the manufacturer's manual for scan tool instructions.

Misfire Monitoring Supported

This menu can be used to determine if the misfire monitoring system is supported on your particular application. All emission-equipped diesel vehicles under 14,000 lbs gross vehicle weight rating (GVWR) use misfire detection. When selecting this function, a message is displayed on the screen: test not supported by this module or test supported by this module.

Comprehensive Component Monitoring Supported

This menu can be used to determine if the comprehensive component monitoring system is supported on your particular application. All emission-equipped diesel vehicles under 14,000 lbs GVWR use comprehensive component monitoring. When selecting this function, a message is displayed on the screen: test not supported by this module or test supported by this module.

Misfire Monitoring Status

This menu can be used to determine the status of the misfire monitoring system on your particular application. All emission-equipped diesel vehicles under 14,000 lbs GVWR use misfire detection. When selecting this function, a message is displayed on the screen: test complete, or not applicable or test not complete.

Comprehensive Component Monitoring Status

This menu can be used to determine the status of the comprehensive component monitoring system on your particular application. All emission-equipped diesel vehicles under 14,000 lbs GVWR use comprehensive component monitoring. When selecting this function, a message is displayed on the screen: test complete, or not applicable or test not complete.

Power-Takeoff (PTO) Status

This menu can be used to determine the status of the power take-off (PTO) system or auxiliary idle control on your particular application. Some transmission OBD monitors are disabled during PTO operation. The vehicle must be out of PTO mode to clear P1000. When selecting this function, a message is displayed on the screen: PTO active or PTO inactive.

Output State Control (OSC)

The OSC aids in diagnosing output actuators associated with the powertrain control module (PCM) for the engine. This mode allows the technician to command the individual actuator state. For example: the output can be enabled or disabled, the duty cycle or the angle of the output can be increased or decreased. The OSC is used to help test the electrical, hydraulic or mechanical components of the vehicle. This function is supported by the vehicle strategy but may not be present on all vehicles or available on all scan tools.

Parameter Identification (PID)

The PID mode allows access to certain data values, analog and digital inputs and outputs, calculated values, and system status information. Throughout the Diagnostic Information, there are references to PID values. PID Data Monitor and Record can be accessed from the scan tool through the Diagnostic Data Link menu.

Selecting Parameter Identification (PID)

Connect the scan tool to the date link connector (DLC). Turn off all accessories. If the vehicle is equipped with a power take-off (PTO) system or auxiliary idle control, it must be turned off to carry out the self-tests.

1. Carry out the necessary vehicle preparation and visual inspection. Refer to Quick Test Operation .
2. Refer to the manufacturer's manual for scan tool instructions.
3. Follow the operating instructions from the menu.
4. Access and select the PIDs to begin monitoring.

Parameter Identification (PID) List

PARAMETER IDENTIFICATION (PID) LIST

SCAN TOOL - DRIVER-OPERATED CONTROLS CHECK

SCAN TOOL - DRIVER-OPERATED CONTROLS CHECK REFERENCE CHART

Freeze frame data allows access to emission related values from specific generic parameter identification (PIDs). These values are stored the instant an emission related diagnostic trouble code (DTC) is stored in continuous memory. This provides a snapshot of the conditions that were present when the DTC was stored. Once one set of freeze frame data is stored, this data remains in memory even if another emission related DTC is stored. When a DTC associated with the freeze frame is erased or a keep alive memory (KAM) reset is carried out, new freeze frame data can be stored. In the event of multiple emission related DTCs in memory, always note the DTC for the freeze frame data.

FREEZE FRAME DATA TABLE

FREEZE FRAME DATA REFERENCE CHART

Accessing Freeze Frame PID Data

Refer to the manufacturer's manual for scan tool instructions.

Resetting Vehicle Specific DTCs

Refer to the manufacturer's manual for scan tool instructions.

OBD PID Data Monitor

The PID monitor for OBD offers real time evaluation of several emissions-related parameters. Most of these are related to the HO2S, for which the diesel has no equivalent.

Flash EEPROM is contained in an integrated circuit internal to the powertrain control module (PCM) and the fuel injection control module (FICM). The flash EEPROM contains the vehicle strategy, including calibration information specific to the vehicle, and is capable of being reprogrammed or reflashed repeatedly.

As part of the calibration there is an area referred to as the vehicle identification (VID) block in the PCM. The VID block must be programmed when installing a new PCM as described under Programming the VID Block for a New PCM. Not carrying out this procedure may generate DTCs: P1635, P1639, VID Block not programmed or is corrupt. The VID block in an existing PCM can also be tailored to accommodate various hardware/parameter changes made to the vehicle since production. Not carrying out this procedure correctly may generate DTC P1635, Tire/Axle Ratio out of Acceptable Range, is one of the main causes for DTC P1639. This is described under Making Changes to the VID Block, and also under Making Changes to the PCM Calibration. The VID block contains many items used by the strategy for a variety of functions. Some of these items include the VIN number, octane adjust, fuel octane, fuel type, vehicle speed limit, tire size, axle ratio, the presence of speed control, and four wheel drive electronic shift-on-the-fly (ESOF) versus manual shift-on-the-fly (MSOF). Only items applicable to the vehicle hardware and supported by the VID block are displayed on the scan tool.

When changing items in the VID block, the strategy places range limits on certain items such as tire and axle ratio. The VID block is also limited to the number of times it can be reconfigured. When this limit is reached, the scan tool displays a message indicating the need to flash the PCM again to reset the VID block.

Each of the procedures described below use the scan tool. Reprogramming can be carried out by a local Ford dealer for any non-Ford facility. There are other enhanced scan tools that may have reprogramming capabilities available. Refer to the manufacturer's manual for details.

Programming the VID Block for a Replacement PCM

The VID block on a replacement PCM is blank and requires programming. There are 2 procedures available. The first is an automatic data transfer from the old PCM to the new PCM, and the second is manual data entry into the new PCM.

Automatic data transfer is carried out if the old PCM is capable of communicating. This is done by the use of a scan tool to retrieve data from the old PCM before removing it from the vehicle. The stored data can be downloaded to the new PCM after installation.

Manual data entry must be carried out if the old module is damaged and/or incapable of communicating. Install a new PCM. Using a compatible scan tool, select and execute Module/Parameter reprogramming referring to the manufacturer's user manual. Make certain that all parameters are included. Incorrectly programming tire size in revolutions per mile, (rev/mile - 63,360 divided by the tire circumference in inches), Axle Ratio, 4x4/4x2, and/or MSOF/ESOF may result in DTCs P1635 or P1639. You may be instructed to contact the As-Built Data Center for the information needed to manually update the VID block with the scan tool. Contact the center ONLY if the old PCM cannot be used or the data is corrupt. For Ford Lincoln-Mercury technicians, contact your National Hotline or the Professional Technician Society (PTS) web site for as-built data. Non-Ford technicians, use the Motorcraft website at motorcraft.com. From the Motorcraft homepage, use the search function to find the Module Programming or As-Built Data.

Making Changes to the VID Block

A PCM which is programmed may require changes to be made to certain VID information to accommodate vehicle hardware. Refer to PCM/Module Reprogramming on the scan tool .

Making Changes to the PCM Calibration

At certain times, the entire flash EEPROM needs to be completely reprogrammed. This is due to changes made to the strategy or calibration after production or the need to reset the VID block because it has reached its limit. Refer to PCM/Module Reprogramming on the scan tool .

Making Changes to the FICM Calibration

At certain times, the entire flash EEPROM needs to be completely reprogrammed. This is due to changes made to the strategy or calibration after production. Refer to PCM/Module Reprogramming on the scan tool .

Note. Strict observance of posted speed limits and attention to driving conditions are mandatory when proceeding through the drive cycle.

Note. Vehicles equipped with power take-off (PTO) or auxiliary idle control must have that system disengaged before the OBD drive cycle is initiated.

The primary intention of the drive cycle is to clear the DTC P1000 and to satisfy the specifications for the Society of Automotive Engineers (SAE) specification J1979. Each on board diagnostic (OBD) monitor must run during the drive cycle.

If the drive cycle is completed and DTC P1000 is not cleared. Repeat the entire drive cycle. If a particular step is interrupted, simply repeat the drive mode. If the drive cycle is interrupted with an ignition OFF, only drive modes that were incomplete must be run.

Rough road conditions may prevent certain steady state conditions and steady accelerations from validating the transmission and load-related monitors.

Some monitors may require extended driving.

Drive Cycle Procedure

1. Ignition ON. Do not crank until the WAIT TO START light cycles, or at least 10 seconds, whichever occurs first.
2. Start the engine. Idle in PARK or NEUTRAL for 40 seconds.
3. Before continuing, engine oil temperature (EOT) must exceed 60°C (140°F).
4. The following outlines the appropriate conditions for running certain OBD monitors that require the engine to be under load: Accelerate steadily to third gear (M/T use fourth gear) and hold at 1,500 RPM for 3 seconds. Accelerate steadily from 56 km/h (35 mph) to 105 km/h (65 mph) over approximately 15 seconds (M/T 11 seconds minimum). Repeat Step a three times while maintaining the conditions in Step 4.a. Before proceeding, turn all accessories off and disengage tow/haul/overdrive cancel.
5. Idle the vehicle for 20 seconds in PARK or NEUTRAL.
6. Ignition OFF.
7. Start the engine. Idle in PARK or NEUTRAL for 40 seconds.
8. Repeat the Quick Test.

Note. If DTC P1000 is present after running the drive cycle: Repeat Step a , being certain to maintain a minimum mass fuel desired (MFDES) of 35 mg/stroke above 2,000 RPM for 11 seconds. Also, maintain a minimum MFDES of 30 mg/stroke above 2,800 RPM for at least 6 seconds. Repeat Step 8 . MFDES must remain below 12 mg/stroke for 11 consecutive seconds.

OBD Parameter Identification (PID) Data Monitor

The PID monitor for OBD offers real time evaluation of several emission-related parameters. The only parameters that apply to 6.0L diesel applications are diagnostic trouble code count (DTC CNT), manifold absolute pressure (MAP), malfunction indicator lamp (MIL), revolutions per minute (RPM), and vehicle speed sensor (VSS).

Refer to the manufacturer's manual for scan tool instructions.

OBD Pending DTCs

Pending DTCs are DTCs that have only set during one drive cycle and may not have set the MIL yet. These DTCs can be identified using the retrieve pending DTCs feature. Additionally, they are found in the vehicle-specific mode retrieve/clear continuous memory DTCs from the instant the DTC is set.

This function only reports pending concerns that have occurred during the present or previous drive cycle, but does not indicate single concerns that happened on any 2 previous drive cycles.

Refer to the manufacturer's manual for scan tool instructions.

Intermittent Diagnostic Techniques

Intermittent diagnostic techniques help find and isolate the root cause of intermittent concerns associated with the powertrain control module (PCM). The material is organized to help find the concern and carry out the repair. There are examples that illustrate the diagnostic techniques. The process of finding and isolating an intermittent starts with recreating a concern symptom, accumulating PCM data, comparing that data to typical values, and analyzing the results.

Before proceeding, make sure that

1. Customary mechanical system tests and inspections do not reveal a problem. (Remember, mechanical component problems can make a PCM system react abnormally.)
2. Review the Technical Service Bulletins (TSBs) and OASIS messages, if available.
3. The Quick Test and associated pinpoint diagnoses have been completed without finding a concern, and the symptom is still occurring.

Recreating the Fault

Recreating the fault is the first step in isolating the cause of the intermittent symptom. If freeze frame data is available, it may help in recreating the conditions at the time of a malfunction indicator lamp (MIL) diagnostic trouble code (DTC). Listed below are some of the conditions for recreating the fault.

Conditions To Recreate The Fault

ENGINE TYPE CONDITIONS REFERENCE CHART

Accumulating Powertrain Control Module (PCM) Data

PCM data can be accumulated in a number of ways. Gather as much data as possible when the concern is occurring to prevent misdiagnosis. Data should be accumulated during different operating conditions and based on the customer description of the intermittent concern. Reference the known good data values located in Typical Diagnostic Reference Values. This requires recording data in 4 conditions for comparison: 1) Key On Engine Off (KOEO), 2) Hot Idle, 3) 48 km/h (30 mph), and 4) 89 km/h (55 mph). Acquisition of PCM PID data using a scan tool is one of the easiest ways to gather information.

For information on the functions of your scan tool, refer to the manufacturer's manual .

Below is a list of the functions available

1. selecting and viewing PIDs
2. storing PIDs
3. recording measurements along with PIDs
4. playback of stored PIDs
5. peripheral inputs

Analyzing PCM Data

Once the concern area is identified, the circuit must be checked to determine if the wiring or component is damaged. When making circuit and component measurements, make sure all accessories and dome and hood lamps are off. Use any of the following methods to diagnose a suspected PCM wire circuit or device. Some methods are particular to a certain type of PCM device.

1. Change Condition to Cause Response by Input
2. Change Input and Verify Output Response
3. Click Testing/Output State Control (Solenoids/Relays)
4. Coil Resistance (Solenoids/Relays)
5. Harness Opens
6. Harness Shorts

Change Conditions to Cause Response by Input

The purpose is to verify the sensor receives and responds to changes.

1. Access, monitor, and record the appropriate sensor PID(s).
2. Create the condition or cause the condition to change.
3. If the value changes appropriately, then it should be operating OK. Examples: The engine oil temperature (EOT) should change from a higher voltage (2.6 volts) for a cold engine, to a lower voltage as the engine warms (0.6 volts). Apply and release the accelerator pedal while monitoring the accelerator pedal position (APP) PID for a change of state. Apply and release the brake pedal while monitoring the brake pedal position (BPP) PID for a change of state.

Change Input and Verify Output Response

The purpose is to verify how the PCM and actuator circuit respond to sensor input.

1. Access, monitor, and record the appropriate sensor PID(s).
2. Create the condition or cause the input condition to change.
3. Monitor any change (response) in the actuator PID or actuator signal circuit with a measuring device. Example: Increase the accelerator pedal position under no load, and observe the RPM DSD PID and circuit change

Coil Resistance (Solenoids/Relays)

The purpose is to measure the correct resistance value of a device.

1. Ignition OFF.
2. Disconnect the component from the vehicle harness.
3. Using an ohmmeter, measure across the component terminals.

Harness Opens

The purpose is to check the harness for open circuits.

1. Ignition OFF.
2. Disconnect the component and the PCM from the vehicle harness.
3. Disconnect the appropriate PCM harness.
4. Using an ohmmeter, isolate the circuit in question from the harness pin to the component connector pin.
5. The resistance value should be less than 5 ohms.

Harness Shorts

The purpose is to check the harness for short circuits (to ground or voltage).

1. Ignition OFF.
2. Disconnect the component and the PCM from the vehicle harness.
3. Using a Digital Multimeter (DMM) FLU77-4 or equivalent, measure the resistance between the signal circuit and signal return circuit, power ground circuit, VREF circuit, or vehicle power.
4. If the resistance value is less than 10,000 ohms, the 2 circuits may be shorted.

Glow Plug Lamp Cycles On/Glow Plugs Recycle/Engine Stumble/Stalls/No Accelerator Pedal Authority Until Return to Idle Position

A PCM reset occurs when the PCM momentarily reboots or is turned off and on while the engine is operating. If the condition occurs a single time, the engine momentarily stumbles and the PCM goes through a normal ignition on cycle, including turning the glow plug lamp and glow plugs on, and also attempts to validate the accelerator pedal position. If the pedal is not at the idle position when this concern occurs, pedal authority is not allowed by the PCM until the accelerator pedal is released and the engine returns to idle.

Probable Causes

1. Momentary loss of power to the PCM or fuel injection control module (FICM): power relays, shorted or open harness, intermittent connectors, grounds.
2. Momentary short to ground of VREF: shorted harness or connector, or sensors that use VREF including exhaust pressure (EP) sensor, injection control pressure (ICP) sensor, manifold absolute pressure (MAP) sensor, barometric pressure (BARO) sensor, accelerator pedal position (APP) sensor, and exhaust gas recirculation (EGR) actuator.

Procedures

1. Check all power and ground connections for the PCM and FICM.
2. Inspect the camshaft position (CMP) sensor and crankshaft position (CKP) sensor harness connectors and the harness for a signal short to ground condition.
3. Remove and inspect the CMP sensor and CKP sensor for possible damage.
4. If the PCM reset condition is repeatable, disconnect the following sensors one at a time and operate the engine to determine if the reset reoccurs: EP sensor, ICP sensor, MAP sensor, APP sensor, EGR sensor. Inspect each harness, including the connector, upon removal.

See also:
• PINPOINT TEST AE
• SYMPTOM CHARTS
• PERFORMANCE DIAGNOSTIC PROCEDURES
• INJECTOR INTERRUPT FOR ENHANCED DIAGNOSTICS
• DRIVE CYCLE
• CLEAR THE CONTINUOUS DIAGNOSTIC TROUBLE CODES (DTCS) AND RESET THE EMISSION MONITORS INFORMATION IN THE POWERTRAIN CONTROL MODULE (PCM