Chart 8

WARNING: This page is about a different variant/trim than selected.

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/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.

SYMPTOM CHART - LACK/LOSS OF POWER

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 ignition ON, engine OFF and ignition 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: GO to PINPOINT TEST HU .
Fuel Delivery System	GO to PINPOINT TEST HC .
Secondary Ignition	For vehicles equipped with a coil pack ignition system, GO to PINPOINT TEST JC . For all others, GO to PINPOINT TEST JB .
Mass Air Flow (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 appropriate Engine article and carry out the Inspection and Verification to continue diagnosis.
Automatic Transmission	REFER to the appropriate Automatic Transaxle/Transmission, Shift Point Road Test to continue diagnosis.
Brake System Drag or Binding	REFER to the appropriate Brake article
Supercharger Bypass System	GO to PINPOINT TEST KJ .
Turbocharger System	GO to PINPOINT TEST HN .
Additional Testing	GO to PINPOINT TEST Z .
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) to carry out the Making Changes to the VID Block procedure. 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 appropriate service information.