- Check the following parameter identifiers (PIDs):
- DPFEGR (if equipped) (hot idle value within 0.15 volt of the key ON, engine OFF value)
- LONGFT1/LONGFT2 (value between -20 and +20%)
- VPWR (value between 10.5 and 17.0 volts, and within 0.5 volt of battery voltage)
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- DPFEGR PID value not within 0.15 volt of key ON, engine OFF value:
- LONGFT1/LONGFT2 value low (-):
- Continue diagnosis. Concentrate checks in areas that would cause the engine to run rich.
- LONGFT1/LONGFT2 value high (+):
- Continue diagnosis. Concentrate checks in areas that would cause the engine to run lean.
- VPWR not between 10.5 and 17.0 volts:
- REFER to the Workshop Manual Section 414-00, Charging System and carry out the Inspection and Verification to continue diagnosis.
- VPWR between 10.5 and 17.0 volts, but not within 0.5 volt of battery voltage:
- CHECK the B+ voltage to the powertrain control module (PCM) power relay. CHECK the VPWR circuit between the PCM and the PCM power relay. CHECK the PWR GND circuits.
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- For vehicles that run rough at idle:
- Check the INJx_F PIDs (the "x" indicates the injector number) with the key ON, engine OFF. There is 1 INJx_F PID for each engine cylinder. All INJx_F PIDs must indicate no fault (or NO).
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- The INJx_F PID(s) indicate a fault (an injector circuit concern is indicated), refer to PINPOINT TEST KG - Fuel Injector
.
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- Mass Air Flow (MAF) Sensor
|
- refer to PINPOINT TEST DC - Mass Air Flow (MAF) Sensor
.
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- Secondary Ignition System
|
- For vehicles equipped with a coil pack ignition system, refer to PINPOINT TEST JC - Secondary Ignition (Coil Pack)
.
- For all others, refer to PINPOINT TEST JB - Secondary Ignition (COP)
.
|
- Fuel Delivery System
|
- refer to PINPOINT TEST HC - Fuel Delivery System
.
|
- Exhaust System
|
- refer to PINPOINT TEST HF - Catalyst Efficiency Monitor and Exhaust Systems
.
|
- Positive Crankcase Ventilation (PCV) System
|
- refer to PINPOINT TEST HG - Positive Crankcase Ventilation (PCV) System
.
|
- EVAP System
|
- refer to PINPOINT TEST HX - Evaporative Emission (EVAP) Monitor and System
.
|
- Charging System
|
- refer to PINPOINT TEST HY - Generator/Regulator System
.
|
- Heated Oxygen Sensor (HO2S) (for Taurus, Taurus X, Sable PZEVs)
|
- refer to PINPOINT TEST DZ - Universal Heated Oxygen Sensor (HO2S)
.
|
- Automatic Transmission
|
- REFER to the Workshop Manual Section 307-01, Automatic Transmission/Transaxle diagnostic strategy to continue diagnosis.
|
- Base Engine
|
- REFER to the Workshop Manual Section 303-00, Engine System and carry out the Inspection and Verification to continue diagnosis.
|
- Intake Air System
|
- refer to PINPOINT TEST HU - Intake Air Systems
.
|
- A/C Pressure (ACP) Transducer Sensor
|
- refer to PINPOINT TEST DS - Air Conditioning Pressure (ACP) Sensor
.
|
- Additional Testing
|
- refer to PINPOINT TEST Z - Intermittent
.
|
- Additional Checks:
- Some vehicles have a TQ_CNTRL PID available. Check this PID to determine if the PCM is reducing torque, and if so, why the torque is being reduced. As a PID display example; 0 equals no torque reduction requested, 1 equals torque truncation, which cuts fuel to protect when line pressure falls to minimum limit and 2 equals traction control event, which cuts fuel/spark for traction control.
- Correct PCM vehicle identification (VID) block information. Refer to Section 2, FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM)
to carry out the Making Changes to the VID Block procedure.
- Be aware of engine RPM/speed limiting functions of the PCM (look for incorrect high vehicle speed signal from ABS, VSS, or OSS).
- Verify the fuel filler cap is correctly tightened or the capless fuel tank filler pipe is correctly sealed and not physically damaged.
- Driveline
- Manual transmission/clutch
- Charging system
- Traction control system (if equipped)
- A/C system (for surge with A/C on)
- Speed control system (for surge with speed control on)
- A/C compressor diode, if equipped (for rolling idle)
|
- REFER to the applicable Workshop Manual section.
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