Chart 8
- Lack/Loss of Power
NOTE:
Verify the symptom is reported under normal driving conditions without excessive engine or vehicle load. Also, be aware of the engine RPM and speed limiting functions of the PCM.
NOTE:
For vehicles equipped with a knock sensor (KS), a lack of power may result when the vehicle is operated with a breakout box installed at the PCM. The KS circuits are not shielded in a breakout box, and KS 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 KS, a lack of power may result if the engine has developed an abnormal noise. The KS may interpret some abnormal noise as detonation and retard spark timing.
| SYSTEM/COMPONENT | REFERENCE (Pinpoint Test unless noted) |
|---|---|
| Automatic Transmission Fluid | Visual. |
| Air Cleaner Element | Visual. |
Check the following PIDS:
|
LONGFT1 or LONGFT2 value low (-): Continue diagnosis. Concentrate checks in areas that would cause the engine to run rich. LONGFT1 or LONGFT2 value high (+): Continue diagnosis. Concentrate checks in areas that would cause the engine to run lean. IMTV_F PID indicates a fault: GO to Pinpoint Test HU . |
| Fuel Delivery System | GO to Pinpoint Test HC . |
| Secondary Ignition | For Fiesta 1.6L TIVCT, GO to Pinpoint Test JC
. For all others, GO to Pinpoint Test JB . |
| Mass Airflow (MAF) Sensor | GO to Pinpoint Test DC . |
| Exhaust System | GO to Pinpoint Test HF . |
| Variable Camshaft Timing (VCT) System | GO to Pinpoint Test HK . |
| Accelerator Pedal Position (APP) Sensor | GO to Pinpoint Test DK . |
| Base Engine | REFER to the service information , Engine System, Diagnosis and Testing to continue diagnosis. |
| Automatic Transmission | REFER to the service information , Automatic Transmission, Shift Point Road Test to continue diagnosis. |
| Brake System Drag or Binding | REFER to the service information , Brake System. |
| Turbocharger System | GO to Pinpoint Test HN . |
| Additional Testing | GO to Pinpoint Test Z . |
Additional Checks:
|
Visual. REFER to the applicable service information. |
| Brake Over Accelerator | CHECK for simultaneous brake pedal and accelerator pedal operation inadvertently activating the brake over accelerator feature. CHECK the BRKOVR_ACTION, BRKOVRD_POSS, and DIST_BRKOVRD PIDs for recent simultaneous brake pedal and accelerator pedal operation. ADVISE the customer that simultaneous brake pedal and accelerator pedal operation by the vehicle operator activates the brake over accelerator feature. REFER to POWERTRAIN CONTROL SOFTWARE for additional information. |