Engine Controls Self-Diagnostics - Diesel: Overview Dodge Cab & Chassis R2500

CONNECTOR IDENTIFICATION

CONNECTOR IDENTIFICATION DIRECTORY

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Description

Intake Air Temperature (IAT) sensor voltage is monitored when ignition is on and battery voltage is more than 10.4 volts. DTC may be stored when IAT sensor voltage at Engine Control Module (ECM) is less than .098 volt for more than 2 seconds. Possible causes are: defective IAT sensor, defective ECM, or defective connectors or wiring.

Intake Air Temperature (IAT) sensor voltage is monitored when ignition is on and battery voltage is more than 10.4 volts. DTC may be stored when IAT sensor voltage at Engine Control Module (ECM) is more than 4.97 volts for more than 2 seconds. Possible causes are: defective IAT sensor, defective ECM, or defective connectors or wiring.

Engine Coolant Temperature (ECT) sensor voltage is monitored when ignition is on and battery voltage is more than 10.4 volts. DTC may be stored when ECT sensor voltage at Engine Control Module (ECM) is less than .8 volt for more than 2 seconds. Possible causes are: defective ECT sensor, defective ECM, or defective connectors or wiring.

Engine Coolant Temperature (ECT) sensor voltage is monitored when ignition is on and battery voltage is more than 10.4 volts. DTC may be stored when ECT sensor voltage at Engine Control Module (ECM) is more than 4.98 volts for more than 2 seconds. Possible causes are: defective ECT sensor, defective ECM, or defective connectors or wiring.

Accelerator Pedal Position Sensor (APPS) voltage is monitored with throttle at less than 15 percent of full throttle for about one second or when vehicle speed is more than 10 MPH for about one second. DTC may be stored if idle valid signal indicates an idle condition while APPS signal voltage does not indicate an idle condition or if idle valid signal does not indicate an idle condition while APPS signal voltage indicates an idle condition. Possible causes are: defective APPS, defective Engine Control Module (ECM), or defective connectors or wiring.

Accelerator Pedal Position Sensor (APPS) voltage is monitored when engine is running. DTC may be stored if low voltage is detected on APPS signal circuit or low voltage is detected between Engine Control Module (ECM) and Powertrain Control Module (PCM). Possible causes are: defective APPS, defective ECM, defective PCM, or defective connectors or wiring.

Accelerator Pedal Position Sensor (APPS) voltage is monitored when engine is running. DTC may be stored if high voltage is detected on APPS signal circuit or high voltage is detected between Engine Control Module (ECM) and Powertrain Control Module (PCM). Possible causes are: defective APPS, defective ECM, or defective connectors or wiring.

Coolant temperature sensor voltage is monitored when engine is running and when engine is off with ignition on. When engine is running, no battery temperature or coolant temperature DTCs can be set and engine coolant temperature must be between -40 to 150°F (-40 to 65°C). DTC will set if coolant temperature does not change more than 6°F within 10 minutes of starting engine.

When engine is not running and ignition is on, no battery temperature, intake air temperature or coolant temperature DTCs can be set and intake air temperature must be less than 80°F (26°C). Battery voltage must be 8-16 volts. DTC will set if coolant temperature reading is greater than 140°C (60°F). Possible causes are: defective Engine Coolant Temperature (ECT) sensor, defective PCM, or defective connectors or wiring.

Coolant temperature sensor voltage is monitored when engine is running, no battery temperature or coolant temperature DTCs and engine coolant temperature must be between 20-130°F (-6 to 55°C). DTC will set if coolant temperature reading is less than 170°F (77°C) after engine has been running for 10-32 minutes. Possible causes are: defective Engine Coolant Temperature (ECT) sensor, defective ECM, or defective connectors or wiring.

Information on when engine performance is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible causes are: defective Fuel Pump Control Module (FPCM) or defective/stuck closed overflow valve.

Information on when water in fuel is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible cause is defective Water-In-Fuel (WIF) sensor.

Water-In-Fuel (WIF) sensor voltage is monitored when ignition is on. DTC may be stored when low WIF sensor signal voltage is detected at Engine Control Module (ECM). Possible causes are: defective WIF sensor, defective ECM, or defective connectors or wiring.

Fuel injection pump temperature is monitored when ignition is on. DTC will be stored if problem exists in fuel injection pump. Possible cause is internal failure of fuel injection pump.

Fuel injection pump operation is monitored when ignition is on. DTC will be stored if problem exists in fuel injection pump. Possible cause is internal failure of fuel injection pump.

Information for when fuel injection pump control circuit is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible causes are: defective fuel pump relay, defective Engine Control Module (ECM), or defective connectors or wiring.

Scheme 22

1. Ensure ignition is off. Remove fuel pump relay from Power Distribution Center (PDC). (Scheme 22) PDC is located at driver's side front corner of engine compartment. Fuel pump relay may also be referred to as fuel injection pump relay. Using 12-volt test light connected to battery voltage, check for voltage at cavity No. 85 (Black wire) in PDC for fuel pump relay. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open in Black wire between cavity No. 85 in PDC and ground connection. Ground connection is located on driver's side fender panel.
2. Note which terminals on fuel pump relay correspond with cavities in PDC. (Scheme 22) Using DVOM, measure resistance between terminals on fuel pump relay that corresponds with cavities No. 85 and 86 in PDC. If resistance is less than 100 ohms, go to next step. If resistance is 100 ohms or more, replace fuel pump relay.
3. Ensure ignition is off. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. see scheme 2 Using 12-volt test light connected to battery voltage, check for voltage at terminals No. 30 (Black/Tan wire) and No. 49 (Black/Tan wire) on ECM connector. (Scheme 9) If test light illuminates brightly at both terminals, go to next step. If test light does not illuminate brightly at any terminal, repair open ground circuit on Black/Tan wire between ECM and ground connection. Ground connection is located at ground connection for negative battery terminal.
4. Ensure fuel pump relay is still removed from PDC and ECM connector is still disconnected. Using DVOM, measure resistance between cavity No. 86 (Brown/White wire) in PDC for fuel pump relay and terminal No. 36 (Brown/White wire) on ECM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Brown/White wire between PDC and ECM.
5. Ensure fuel pump relay is still removed from PDC and ECM connector is still disconnected. Using DVOM, measure resistance between ground and cavity No. 86 (Brown/White wire) in PDC for fuel pump relay. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Brown/White wire between PDC and ECM.
6. It is assumed that ECM is defective and should be replaced. See REMOVAL, OVERHAUL & INSTALLATION - RAM PICKUP - DIESEL article. Before installing replacement ECM, ensure all DTCs have been repaired to prevent damaging replacement ECM.

Fuel injection pump timing failure is monitored with ignition on. DTC may be stored when Engine Control Module (ECM) senses engine speed is more than 300 RPM and fuel command and timing control are within predetermined parameters. Possible causes are: defective fuel injection pump, fuel injection pump gear improperly aligned, restricted fuel filter or restricted transfer pump inlet line.

Information for when decreased engine performance due to engine overheat condition is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible cause is engine temperature is not within 10°F of Engine Coolant Temperature (ECT) sensor temperature.

Idle validation signals are monitored when ignition is on. DTC may be stored if Engine Control Module (ECM) senses no voltage signal from Idle Validation Switch (IVS) No. 1 and/or IVS No. 2. Possible causes are: defective Accelerator Pedal Position Sensor (APPS), defective ECM, or defective connectors or wiring.

Idle validation signals are monitored when ignition is on. DTC may be stored if Engine Control Module (ECM) senses high voltage signal from Idle Valve Switch (IVS) No. 1 and/or IVS No. 2. Possible causes are: defective Accelerator Pedal Position Sensor (APPS), defective ECM, or defective connectors or wiring.

Transfer pump is referred to as fuel transfer pump in test procedure. Information for when fuel transfer pump circuit is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible causes are: defective fuel transfer pump, defective Engine Control Module (ECM), or defective connectors or wiring.

Information for when fuel shutoff signal voltage is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible cause is defective Engine Control Module (ECM).

Turbo boost limit is monitored when ignition is on. DTC may be stored if Engine Control Module (ECM) senses engine speed is more than 2200 RPM with no intake air pressure sensor out of range DTCs present. Possible cause is mechanical wastegate failure.

Information for when Manifold Air Pressure (MAP) sensor is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible causes are: improper boost pressure, DTC for MAP sensor voltage too high or too low exists, DTC for auxiliary 5-volt output exists, defective MAP sensor, defective Engine Control Module (ECM), or defective connectors or wiring.

Manifold Air Pressure (MAP) sensor voltage is monitored when engine speed is more than 416 RPM but less than 3520 RPM and battery voltage is more than 10.4 volts. DTC may be stored if Engine Control Module (ECM) senses MAP sensor signal voltage is less than .1 volt for 2 seconds with engine running. Possible causes are: improper boost pressure, DTC for auxiliary 5-volt output exists, defective MAP sensor, defective ECM, or defective connectors or wiring.

Manifold Air Pressure (MAP) sensor voltage is monitored when engine speed is more than 416 RPM but less than 3520 RPM and battery voltage is more than 10.4 volts. DTC may be stored if Engine Control Module (ECM) senses MAP sensor signal voltage is more than 4.88 volts at start or with engine running for 2 seconds. Possible causes are: improper boost pressure, DTC exists for high voltage on intake air temperature sensor, engine coolant temperature sensor or oil pressure sensor, defective MAP sensor, defective ECM, or defective connectors or wiring.

Fuel injection pump mechanical failure fuel valve feedback circuit is monitored when ignition is on. DTC may be stored when Engine Control Module (ECM) senses fuel command is within predetermined parameters, low battery voltage exists and fuel delivery valve solenoid is energized with more than 9 volts. Possible causes are: defective fuel injection pump, defective battery, defective fuel pump relay, or defective connectors or wiring.

Fuel injection pump fuel valve circuit is monitored after current feedback monitoring is complete and engine speed is approximately 700 RPM. DTC may be stored when Engine Control Module (ECM) does not receive a signal from the solenoid valve to indicate valve movement. Possible causes are: defective fuel injection pump.

Fuel injection pump fuel valve open circuit is monitored when ignition is on. DTC may be stored when Engine Control Module (ECM) senses engine speed is more than 100 RPM and low current or no current is detected at fuel metering valve. Possible causes are: defective fuel injection pump, defective battery, or defective connectors or wiring.

Information for when fuel injection pump fuel valve current is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible cause is internal fuel injection pump failure.

Cylinder misfire is monitored with engine running at idle (less than 880 RPM on A/T models or less than 860 RPM on M/T models), engine coolant temperature is more than 140°F (60°C), Power Take-Off (PTO) is inactive and vehicle speed is zero MPH. DTC may be stored when Engine Control Module (ECM) senses predetermined time required for crankshaft to rotate 120 degrees during firing interval of cylinder being tested is different than time required for crankshaft to rotate 120 degrees during firing interval of previous cylinder. Possible causes are: DTC does not match FREEZE FRAME DTC, DTC SPECIFIC GOOD TRIP counter does not change to zero, engine mechanical problem, defective tone wheel, defective Camshaft Position (CMP) sensor, or defective connectors or wiring.

Crank reference signal is monitored when engine is running. DTC may be stored when engine speed at Powertrain Control Module (PCM) is less than 800 RPM while engine speed at Engine Control Module (ECM) is greater than 1024 RPM and battery voltage is 10.5-15.0 volts. Possible causes are: defective ECM, defective PCM, or defective connectors or wiring.

Camshaft Position Sensor (CMP) sensor signal is monitored when engine is running above 60 RPM and battery voltage is 8-15 volts. DTC may be stored when CMP sensor does not deliver camshaft position signal to Engine Control Module (ECM) for longer than 2 seconds or incorrect tone wheel signal tooth count occurs 25 times within 8 seconds. Possible causes are: DTC does not match FREEZE FRAME DTC, defective CMP sensor, defective camshaft drive gear, defective ECM, open sensor 5-volt signal circuit, open sensor ground circuit or defective connectors or wiring.

Camshaft Position Sensor (CMP) sensor supply voltage is monitored when ignition is on. DTC may be stored when CMP sensor supply voltage is less than 4.2 volts for 2 seconds. Possible causes are: defective CMP sensor or short to ground in 5-volt supply circuit.

Camshaft Position Sensor (CMP) sensor supply voltage is monitored when ignition is on. DTC may be stored when CMP sensor supply voltage is 5.5 volts or more for 2 seconds. Possible causes are: defective CMP sensor or short to ground in 5-volt supply circuit.

Information for when fuel injection pump speed/position sensor signal is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible cause is internal fuel injection pump failure.

Intake air heater relay No. 1 control circuit is monitored during the first second that ignition is turned on. DTC may be stored if Engine Control Module (ECM) does not sense that intake air heater turned on. Possible causes are: DTC does not match FREEZE FRAME DTC, defective ECM, defective intake air heater relay No. 1, or defective connectors or wiring.

WAIT-TO-START light is monitored when ignition is on. DTC may be stored when WAIT-TO-START light does not come on within 2 seconds after ignition is turned on. Possible causes are: defective WAIT-TO-START light bulb, defective Engine Control Module (ECM), or defective connectors or wiring.

Intake air heater relay No. 2 control circuit is monitored during the first second that ignition is turned on. DTC may be stored if Engine Control Module (ECM) does not sense that intake air heater turned on. Possible causes are: DTC does not match FREEZE FRAME DTC, defective ECM, defective intake air heater relay No. 2, or defective connectors or wiring.

Fuel level unit may also be referred to as fuel level sensor or fuel level sending unit. Fuel level unit change over miles is monitored when engine is running and fuel level is either less than 15 percent of fuel tank capacity or more than 85 percent of fuel tank capacity. DTC may be stored when Powertrain Control Module (PCM) senses low fuel for more than 120 miles or fuel level does not change by at least 14 percent within 250 miles. Possible causes are: defective fuel level sensor or damaged or obstructed fuel tank.

Fuel level sending unit voltage is monitored when ignition is on and battery voltage is more than 10.4 volts. Fuel level sending unit is referred to as fuel level sensor in the following test procedure. DTC may be stored when fuel level sensor voltage at Powertrain Control Module (PCM) is less than .2 volt for 5 seconds. Possible causes are: defective fuel level sensor, defective PCM, or defective connectors or wiring.

Vehicle speed sensor signal is monitored when boost pressure is more than 7 psi (.5 kg/cm 2 ) and engine speed is more than 1024 RPM but less than 2784 RPM. DTC may be stored when Powertrain Control Module (PCM) senses no vehicle speed signal from Controller Anti-Lock Brake (CAB) module for more than 15 seconds for 2 consecutive trips. Possible causes are: CAB module DTCs exist, defective CAB module, defective PCM, or defective connectors or wiring.

Vehicle Speed Sensor (VSS) signal is monitored when no VSS or CCD DTCs are set. DTC may be stored when vehicle speed signal from VSS indicates more than 20 MPH for 2 seconds and ECM vehicle speed indicates less than 10 MPH and PCM does not receive a VSS signal from Controller Anti-Lock Brake (CAB) module. Possible causes are: related CAB module DTCs are stored, defective CAB, defective ECM, defective PCM, or defective connectors or wiring.

Oil pressure voltage is monitored when ignition is on and battery voltage is more than 10.4 volts. DTC may be stored when input voltage from engine oil pressure sensor at Engine Control Module (ECM) is less than .1 volt. Possible causes are: multiple DTCs are stored, defective ECM, defective engine oil pressure sensor, or defective connectors or wiring.

Oil pressure voltage is monitored when ignition is on and battery voltage is more than 10.4 volts. DTC may be stored when input voltage from engine oil pressure sensor at Engine Control Module (ECM) is more than 4.9 volts. Possible causes are: multiple DTCs are stored, defective ECM, defective engine oil pressure sensor, or defective connectors or wiring.

Information for when oil pressure too low signal is monitored and conditions required for DTC to be stored are not available from manufacturer. Low engine speed under load may cause oil pressure to become less than specified limits. Possible causes are: defective engine oiling system or defective engine oil pressure sensor.

Charging system voltage is monitored when ignition is on. DTC may be stored if battery supply voltage (B+ circuit) at Engine Control Module (ECM) is less than 6 volts. Possible causes are: defective charging system, low charged or defective battery, defective battery cables, defective generator, defective ECM, or defective connectors or wiring.

Charging system voltage is monitored when ignition is on. DTC may be stored if battery supply voltage (B+ circuit) at Engine Control Module (ECM) is more than 17 volts. Possible causes are: defective charging system, open or high resistance on ECM ground circuits, or defective connectors or wiring.

Powertrain Control Module (PCM) internal controller failure is monitored when ignition is on. DTC may be stored when internal checksum for software failed or does not match calculated value. Possible cause is a defective PCM.

Engine Control Module (ECM) fueling calibration error is monitored when ignition is on. DTC may be stored when any fueling value is out of range for one second. Possible cause is defective ECM.

Information for when Engine Control Module (ECM) failure is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible cause is defective ECM.

Generator field switching is monitored when ignition is on and engine is running. DTC may be stored if Powertrain Control Module (PCM) tries to regulate generator field with no result during monitoring. Possible causes are: defective generator, defective PCM, or defective connectors or wiring.

A/C clutch relay may also be referred to as A/C compressor clutch relay. A/C clutch relay circuit is monitored when ignition is on and battery voltage is more than 10.4 volts. DTC may be stored if an open or short exists in A/C clutch relay control circuit. Possible causes are: defective A/C clutch relay, defective Powertrain Control Module (PCM), or defective connectors or wiring.

Idle select switch signal is monitored when ignition is on. DTC may be stored if Fuel Pump Control Module (FPCM) detects a false low idle select signal. FPCM is incorporated into fuel injection pump and may also be referred to as the fuel injection pump when referencing to wiring diagram. Possible causes are: defective fuel injection pump, defective Engine Control Module (ECM), or defective connectors or wiring.

Fuel injector pump is referred to as fuel injection pump in test procedures. Information for when fuel injector pump battery voltage is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible cause is defective fuel injection pump.

Information for when fuel injection pump controller is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible causes are: defective fuel pump relay, defective Engine Control Module (ECM), or defective connectors or wiring. Fuel injection pump controller may also be referred to as fuel injection pump control module.

Accelerator Pedal Position Sensor (APPS) supply voltage is monitored when engine is running. DTC may be stored if Engine Control Module (ECM) senses high voltage on APPS supply circuit. Possible causes are: defective APPS, defective ECM, or defective connectors or wiring.

Fuel injection pump controller supply voltage is monitored when ignition is on. DTC may be stored if low voltage exists. Possible causes are: defective battery, defective fuel injection pump ground circuit connectors or wiring. Fuel injection pump controller may also be referred to as fuel injection pump control module.

Temperature rise from intake air heaters is monitored for first 15 seconds of engine operation. DTC may be stored if initial Intake Air Temperature (IAT) sensor reading is 0-66°F (-17.8 to 18.8°C), Battery Temperature Sensor (BTS) and IAT sensor are within 10°F of each other, time between end of preheat and engine run state is less than 30 seconds, engine is cranked for less than 5 seconds before engine starts, preheat is completed before engine starts, post-heat is active and no IAT sensor or intake air heater relay DTCs exist. Possible causes are: DTC does not match FREEZE FRAME DTC, DTC SPECIFIC GOOD TRIP counter does not change to zero, defective intake air heater relay, defective cable from intake air heater relay to intake air heater, defective battery cable to intake air heater relay or defective intake air heater.

Accelerator Pedal Position Sensor (APPS) supply voltage is monitored when engine is running. DTC may be stored if low APPS signal voltage exists, or low voltage is detected between Engine Control Module (ECM) and Powertrain Control Module (PCM). Possible causes are: defective APPS, defective ECM, or defective connectors or wiring.

Auto Shutdown (ASD) relay control circuit is monitored when ignition is on and battery voltage is more than 10.4 volts. DTC may be stored if an open or short is detected in ASD relay control circuit. Possible causes are: defective ASD relay, defective Powertrain Control Module (PCM), or defective connectors or wiring.

Auto Shutdown (ASD) relay output voltage is monitored when ignition is on, battery voltage is more than 10.4 volts and engine speed is more than 40 RPM. DTC may be stored if Powertrain Control Module (PCM) senses no voltage when ASD relay is energized. Possible causes are: DTC does not match FREEZE FRAME DTC, defective ASD relay, defective Powertrain Control Module (PCM), or defective connectors or wiring.

Information for when auxiliary 5-volt output is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible causes are: defective Engine Control Module (ECM), or defective connectors or wiring.

Information for when auxiliary 5-volt output is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible causes are: defective Camshaft Position (CMP) sensor, defective Engine Control Module (ECM), defective Manifold Air Pressure (MAP), defective engine oil pressure sensor, defective Water-In-Fuel (WIF) sensor, or defective connectors or wiring.

Ambient/battery temperature sensor voltage is monitored when ignition is on. DTC may be stored if Powertrain Control Module (PCM) senses voltage from Battery Temperature Sensor (BTS) is more than 4.9 volts for 3 seconds. Possible causes are: defective BTS, defective PCM, or defective connectors or wiring.

Ambient/battery temperature sensor voltage is monitored when ignition is on. DTC may be stored if Powertrain Control Module (PCM) senses voltage from Battery Temperature Sensor (BTS) is less than .5 volts for 3 seconds. Possible causes are: defective BTS, defective PCM, or defective connectors or wiring.

Charging system voltage is monitored when ignition is on and engine is running. DTC may be stored in Powertrain Control Module (PCM) if PCM attempts to regulate generator field with no detected field problems but voltage output does not decrease. Possible causes are: defective Battery Temperature Sensor (BTS), defective generator, defective PCM, or defective connectors or wiring.

Note. To identify negative (-) terminal of generator for testing purposes, use a DVOM and measure voltage at both field terminals. The positive (+) terminal will show battery voltage and the negative (-) terminal will indicate 3-8 volts less than positive (+) terminal voltage.

Speed control solenoids circuits are monitored when ignition is on, speed control is on and vehicle speed is more than 35 MPH. DTC may be stored in Powertrain Control Module (PCM) if PCM actuates speed control vacuum and vent solenoids and solenoids do not operate. Possible causes are: improperly adjusted brake switch, defective brake switch, defective speed control servo, defective PCM, or defective connectors or wiring.

Speed control switch is monitored when ignition is on. DTC may be stored in Powertrain Control Module (PCM) if open is detected in speed control on/off switch circuit and voltage is more than 4.8 volts for more than 2 minutes. Possible causes are: defective clockspring, defective speed control on/off switch, defective PCM, or defective connectors or wiring.

Speed control switch is monitored when ignition is on and battery voltage is more than 10.4 volts. DTC may be stored in Powertrain Control Module (PCM) if speed control on/off switch circuit voltage is less than .39 volt for 2 minutes. Possible causes are: defective clockspring, defective speed control on/off or resume/accel switch, defective Powertrain Control Module (PCM), or defective connectors or wiring.

Charging system voltage is monitored when ignition is on and engine is more than 1500 RPM for longer than 25 seconds. DTC may be stored in Powertrain Control Module (PCM) if PCM regulates generator field with no detected field problems but voltage output does not increase. Possible causes are: defective Battery Temperature Sensor (BTS), defective PCM, or defective connectors or wiring.

Information for when speed control power relay or 12-volt driver circuit is monitored and conditions required for DTC to be stored are not available from manufacturer. Possible causes are: improperly adjusted brake switch, defective brake switch, defective speed control servo, defective Powertrain Control Module (PCM), or defective connectors or wiring.

Information for when fuel injection pump is monitored is not available from manufacturer. Possible cause is defective fuel injection pump.

Communication between Engine Control Module (ECM) and injection pump module is monitored when ignition is on. Injection pump module is referred to as Fuel Pump Control Module (FPCM) in test procedures. DTC may be stored if the time between messages communicated between ECM and FPCM is more than 3 seconds or FPCM does not receive message from ECM. Possible causes are: defective ECM, defective data link circuits between ECM and FPCM, or defective connectors or wiring.

DTC is monitored when ignition is on and engine is running. DTC may be stored when no signal exists within specified window parameters with no Camshaft Position (CMP) sensor or CKP DTCs present. Possible causes are: DTC counter does not change to zero, fuel injection pump static timing incorrect, defective ECM, or defective connectors or wiring.

Information for when fuel injection pump controller calibration is monitored is not available from manufacturer. Possible cause is defective fuel injection pump. Fuel injection pump controller may also be referred to as fuel injection pump control module.

This Engine Control Module (ECM) DTC indicates that a stored DTC exists in the Powertrain Control Module (PCM).

The Powertrain Control Module (PCM) indicates that a stored DTC exists in the Engine Control Module (ECM).

Information for when no bus messages are received from companion module is monitored and conditions required for DTC to be stored are not available from manufacturer. This DTC may exist if Engine Control Module (ECM) has been disconnected or Powertrain Control Module (PCM) is flashed to obtain proper programming. Possible causes are: defective ECM, open bus circuit, or defective connectors or wiring.

Powertrain Control Module (PCM) EEPROM write is monitored when ignition is on. DTC may be stored if attempt to program or write to the internal EEPROM failed. Possible cause is defective PCM.

Information for when no bus messages are received from Powertrain Control Module (PCM) is monitored and conditions required for DTC to be stored are not available from manufacturer. This DTC may exist if PCM has been disconnected or PCM is flashed to obtain proper programming. Possible causes are: defective PCM, open bus circuit, or defective connectors or wiring.

Park/Neutral (P/N) switch is monitored when transmission is in Park or Neutral and not in limp-in mode. DTC may be stored if an incorrect P/N switch state for an given mode of operation. Possible causes are: defective PCM, defective P/N switch or defective wiring.