QT1 CARRY OUT THE PCM QUICK TEST
Note. For applications that use a stand-alone transmission control module (TCM), the PCM does not output TCM related diagnostic trouble codes (DTCs). Refer to the appropriate AUTOMATIC TRANSMISSION/TRANSAXLE article for diagnosis and testing.
- Complete the preliminary checks looking for obvious concerns that may relate to the symptom. Check for the following items: related electrical connectors or fuses vacuum lines (leaks, routing) air intake system (leaks, restrictions) fuel quality (octane, contamination, winter/summer blend) cooling system (engine operating at proper temperature)
- Access any related Technical Service Bulletin (TSB) information (if available).
- Carry out the PCM self-test to access any DTCs. Record any key on engine off (KOEO), key on engine running (KOER) (if the engine runs) and continuous memory (MIL and non-MIL) DTCs.
- Are any DTCs present?
| Yes | No |
|---|
| GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS for direction to repair DTCs after noting the following: Diagnose the DTCs in the following order (begin diagnosis with the first DTC output in that mode and diagnose any circuit related DTCs first). For multiple circuit DTCs that are set as a result of a concern with more than one component, REFER to the appropriate SYSTEM WIRING DIAGRAMS article and identify the common cause such as SIG RTN, VREF, or VPWR. Continue DTC diagnosis by referring to the appropriately identified pinpoint test. Any KOEO self-test DTCs Any KOER self-test DTCs Any continuous memory self-test DTCs. Retrieve any available freeze frame data and disregard any identical/related continuous DTCs already repaired. | GO to STEP 2: NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX for direction to the proper symptom chart in STEP 3: NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHARTS . If the symptom is not listed, REFER to the applicable service information article to continue diagnosis. |
Step 2: No Diagnostic Trouble Codes (DTCs) Present Symptom Chart Index
DRIVEABILITY - PERFORMANCE WHILE DRIVING CONCERNS
ADDITIONAL DRIVEABILITY CONCERNS
Chart 1
- Stalls/Quits: Idle, Acceleration, Cruise, Stall After Start
- Runs Rough
- Misses
- Buck/Jerk
- Hesitation/Stumble
- Surge
- Unique Idle Concerns: Rolling Idle
- Intermittent Rough Idle
Note. For some vehicle applications, the engine may stall if left running while refueling. Advise the customer to turn the engine off while refueling to avoid contamination or damage to the evaporative emission (EVAP) system.
| SYSTEM/COMPONENT | REFERENCE (Pinpoint Test unless noted) |
|---|
| 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) | DPFEGR PID value not within 0.15 volt of key ON, engine OFF value: For vehicles equipped with an exhaust gas recirculation system module (ESM), refer to PINPOINT TEST HH - Exhaust Gas Recirculation System Module (ESM) . For all others, refer to PINPOINT TEST HE - Exhaust Gas Recirculation (EGR) Systems . 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 appropriate CHARGING SYSTEM GENERAL INFORMATION article . 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. |
| 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). | The INJx_F PID(s) indicate a fault (an injector circuit concern is indicated), refer to PINPOINT TEST KG - Fuel Injector . |
| Mass Air Flow (MAF) Sensor | Refer to PINPOINT TEST DC - Mass Air Flow (MAF) Sensor . |
| 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 . |
| Automatic Transmission | REFER to appropriate AUTOMATIC TRANSMISSION/TRANSAXLE article. |
| Base Engine | REFER to the appropriate ENGINE article. |
| Intake Air System (for vehicles equipped with an IAC valve) | 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, FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . 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 properly tightened and not physically damaged. Drivelines 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 service information article. |
Chart 2
- Starting Concerns: Hard Start/Long Crank/Erratic Start/Erratic Crank
Chart 3
- Starting Concerns: No Start (Engine Cranks)
Note. An extended crank because of a no start may load the exhaust system with raw fuel, damaging the catalytic converter after the engine starts. For vehicles equipped with a secondary air injection (AIR) system, carry out the following after the no start concern is repaired: Disconnect the electric AIR pump relay, run the engine until the surplus fuel is used up, and connect the relay. Disconnecting the relay may set a continuous memory PCM DTC that needs to be cleared.
Chart 4
- Unique Idle Concerns: Slow Return To Idle
Chart 5
- Unique Idle Concerns: Fast Idle
- Diesels/Runs On
Note. If the vehicle runs normally with the key in the OFF position, check for a damaged ignition switch, an IGN RUN circuit short to voltage, or a VPWR circuit short to voltage. Refer to the applicable SYSTEM WIRING DIAGRAMS article or service information article.
| SYSTEM/COMPONENT | REFERENCE (Pinpoint Test unless noted) |
|---|
| Base Engine Check for air leaks, including proper sealing of intake manifold and components/vacuum lines attached to intake air (such as the PCV, EGR or IAC valve/vacuum lines). | Visual. REFER to the appropriate ENGINE article. |
| Verify the engine operates at normal temperature. | Visual. REFER to the appropriate ENGINE COOLING article or Step 2: No Diagnostic Trouble Codes (DTCs) Present Symptom Chart Index , to diagnose any cooling system concerns that are present. |
| Fast idle concerns (for vehicles equipped with an IAC valve) With the key ON, engine OFF monitor the TP MODE PID while wiggling the TP sensor circuits. The TP MODE PID can also be monitored during vehicle drive. With the throttle closed, the TP MODE PID must be C/T (closed throttle). | TP MODE PID is not C/T with the throttle closed: At vehicle start, the TPREL begins at about 1.25 volts and counts down to the lowest TP voltage value seen since engine start. If the TP voltage value goes below the normal range, then increases again, TPREL sets to the lower voltage. If the TP voltage is about 0.04 volt greater than the TPREL value at closed throttle, the PCM goes into part throttle mode. MONITOR the TP voltage and TPREL PIDs for sudden changes while checking for intermittent TP circuit/connector concerns. CHECK for loose or worn throttle plates. If no concern is found, refer to PINPOINT TEST Z - Intermittent . |
| Intake Air System Leaks (for vehicles equipped with an IAC valve) | Refer to PINPOINT TEST HU - Intake Air Systems . |
| Additional Testing | Refer to PINPOINT TEST Z - Intermittent . |
Chart 6
- Unique Idle Concerns: Low/Slow Idle
- Stalls/Quits: Deceleration
Chart 7
Chart 8
Note. Verify the symptom is reported under normal driving conditions without excessive engine or vehicle load. Also, be aware of the engine RPM/speed limiting functions of the PCM.
Note. For vehicles equipped with a knock sensor, a lack of power may result when the vehicle is operated with a breakout box installed at the PCM. The knock sensor circuits are not shielded in the breakout box, and knock sensor signal noise may be noticed by the PCM. If this happens, spark timing is retarded and a lack of power may result.
Note. For applications with a knock sensor, a lack of power may result if the engine has developed an abnormal noise. The knock sensors may interpret some abnormal noise as detonation and retard spark timing.
| SYSTEM/COMPONENT | REFERENCE (Pinpoint Test unless noted) |
|---|
| Automatic Transmission Fluid | Visual |
| Throttle Linkage | Visual |
| Air Cleaner Element | Visual |
| Check the following PIDS: LONGFT1/LONGFT2 (value between -20 and +20%) IMTVF (if equipped): For both key ON, engine OFF and key ON, engine running with the transmission in PARK/NEUTRAL and the engine RPM greater than 3,000 RPM, the PID should indicate no fault (or NO) in both situations. | 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. IMTVF PID indicates a fault: refer to PINPOINT TEST HU - Intake Air Systems . |
| Fuel Delivery System | Refer to PINPOINT TEST HC - Fuel Delivery System . |
| Secondary Ignition | 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) . |
| MAF Sensor | Refer to PINPOINT TEST DC - Mass Air Flow (MAF) Sensor . |
| Exhaust System | Refer to PINPOINT TEST HF - Catalyst Efficiency Monitor and Exhaust Systems . |
| Variable Camshaft Timing (VCT) System | Refer to PINPOINT TEST HK - Variable Camshaft Timing (VCT) . |
| Accelerator Pedal Position Sensor | Refer to PINPOINT TEST DK - Accelerator Pedal Position Sensor . |
| Base Engine | REFER to the appropriate ENGINE article. |
| Automatic Transmission | REFER to the appropriate AUTOMATIC TRANSMISSION/TRANSAXLE article. |
| Brake System Drag or Binding | REFER to the appropriate BRAKE SYSTEM - GENERAL INFORMATION . |
| Supercharger Bypass System | Refer to PINPOINT TEST KJ - Supercharger Bypass Control . |
| 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. Customer driving habits Correct PCM vehicle identification (VID) block information. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . Intake manifold runner control (IMRC) linkage (if equipped) Clutch (M/T) Charging system Engine RPM/speed limiting functions of the PCM (look for incorrect high vehicle speed signal from ABS, VSS, or OSS) | Visual. REFER to the applicable service information article. |
Chart 9
Chart 10
Note. Driving styles may have a significant influence on fuel economy. Verify the concern before starting an in-depth diagnosis. The following external factors may contribute to poor fuel economy
- stop and go driving
- improper tire pressure and size
- vehicle loads (such as trailer towing)
- extended winter warm-up conditions
- high speed driving
- incorrect axle ratio
- road/weather conditions
- aftermarket add-ons
- short run operations
- customer expectations
Chart 11
Chart 12
- Warning Indicators: Check Fuel Cap Indicator, Malfunction Indicator Lamp (MIL), Power Take Off (PTO), Temperature Warning Indicator or Gauge (applications with CHT sensor only), Transmission Control Indicator Lamp (TCIL), Powertrain Malfunction Indicator (Wrench)
- PTO Concerns: Not Working Correctly
Note. If the symptom is both a MIL on and exhaust emission test failure, GO directly to Chart 11. If the engine is a no start, GO directly to Chart 3. If the engine runs rough at idle, GO directly to Chart 1.
| SYSTEM/COMPONENT | REFERENCE (Pinpoint Test unless noted) |
|---|
| Verify the fuel filler cap is properly tightened. | Visual |
| Check Fuel Cap Indicator Never/always on | REFER to the appropriate INSTRUMENT CLUSTER article or appropriate INFORMATION AND MESSAGE CENTER article. |
| MIL Always on when the engine is running (no DTCs present) Never on (including during indicator prove out) | REFER to the appropriate INSTRUMENT CLUSTER article . |
| PTO PTO indicator never/always on PTO not working correctly | Refer to PINPOINT TEST FB - Power Take Off (PTO) . |
| Temperature Warning Indicator or Gauge (applications with CHT sensor only) Engine cooling system Indicator circuits | For an engine that is overheating, REFER to the appropriate ENGINE COOLING article. Be aware that since a PCM DTC is not present, the PCM is not attempting to activate the indicator. For an engine operating at normal temperature, refer to PINPOINT TEST DL - Cylinder Head Temperature (CHT) Sensor . |
| TCIL Always on when the engine is running (no DTCs present) Never on | For E-Series, refer to PINPOINT TEST TB - Transmission Control Switch (TCS)/ Transmission Control Indicator Lamp (TCIL) . For all others, REFER to the appropriate INSTRUMENT CLUSTER article. |
| Powertrain Malfunction Indicator (Wrench) Never/always on | REFER to the appropriate INSTRUMENT CLUSTER article. |
| Additional Testing | Refer to PINPOINT TEST Z - Intermittent . |
Chart 13
- Automatic Transmission (A/T) Shift Concerns: Upshift, Downshift, Engagement
Chart 14
- Instrumentation: Tachometer Inoperative, Speedometer/Odometer Inoperative, Boost Gauge Indicates Higher Than Normal Boost, Fuel Gauge Inoperative
| SYSTEM/COMPONENT | REFERENCE (Pinpoint Test unless noted) |
|---|
| Tachometer Inoperative | REFER to the appropriate INSTRUMENT CLUSTER article. |
| Speedometer/Odometer Inoperative | REFER to the appropriate INSTRUMENT CLUSTER article. |
| Boost Gauge (for vehicles equipped with a supercharger) Indicates higher than normal boost | For supercharger bypass control concerns, refer to PINPOINT TEST KJ - Supercharger Bypass Control . For charge air cooler (CAC) system concerns, refer to PINPOINT TEST KP - Charge Air Cooler (CAC) Pump . |
| Fuel Gauge Inoperative Fuel gauge always indicates full or empty | REFER to the appropriate INSTRUMENT CLUSTER article. |
| Instrumentation | REFER to the appropriate INSTRUMENT CLUSTER article. |
Chart 15
- Oil System Concerns: High Oil Consumption, Leaks
Chart 16
- Cooling System Concerns: Electric Cooling Fan(s) Does Not Operate (Low, Medium, High or Variable Speed), Cooling Fan Clutch Does Not Operate
Chart 17
- Cooling System Concerns: Electric Cooling Fan(s) Always Runs
Note. This chart is only intended to diagnose an electric cooling fan that always runs with a cool engine and the A/C and defroster off.
| SYSTEM/COMPONENT | REFERENCE (Pinpoint Test unless noted) |
|---|
| Cooling Fan A/C pressure switch (ACPSW) or ACP transducer sensor circuits | For Crown Victoria/Grand Marquis, Five Hundred/Freestyle/Montego, Fusion/Milan/MKZ, Edge/MKX, and Town Car, VERIFY the results of the PCM self-test. Visually INSPECT the cooling fan for concerns. For all others, refer to PINPOINT TEST KF - Fan Control (FC) Relays . |
| Cooling System | REFER to the appropriate ENGINE COOLING article. |
Chart 18
- Exhaust System Concerns: Visible Smoke
Note. Black smoke indicates a rich fuel mixture, blue smoke indicates burning oil, and white smoke indicates water in the combustion chamber.
Chart 19
- Fuel System Concerns: Odor, Engine Compartment
Chart 20
- Engine Noise (under hood)
Chart 21
- Climate Control: Lack of A/C Cooling, A/C Not Functioning, A/C Always On, or A/C Compressor Runs Continuously
| SYSTEM/COMPONENT | REFERENCE (Pinpoint Test unless noted) |
|---|
| A/C System | If sent here from the service information article with WAC_F PID indicating a fault (or YES), GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS and follow the directions for KOEO DTC P0645. For all others, REFER to the appropriate CLIMATE CONTROL SYSTEM - GENERAL INFORMATION article. |
Chart 22
- Exhaust System Concerns: Odor (Sulfur or Rotten Egg Smell)
Note. A slight sulfur smell may be normal. Catalysts with less than 8,000-16,000 kilometers (5,000-10,000 miles), either from a new vehicle or new catalyst, are likely to have a sulfur smell due to the highly active state of new catalysts. Installing a new catalyst may actually make the symptom worse.
Chart 23
- Starting Concerns: No Crank
| SYSTEM/COMPONENT | REFERENCE (Pinpoint Test unless noted) |
|---|
| Add-on Anti-Theft Devices | Visual. CHECK with the customer. |
| Anti-Theft | REFER to the appropriate ANTI-THEFT article. |
| Base Engine Starting system | REFER to the appropriate STARTING SYSTEM article. |
