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Diagnostic Procedure

NO. 12 LACK/LOSS OF POWER-ACCELERATION/CRUISE DIAGNOSTIC PROCEDURE

STEP INSPECTION RESULTS ACTION
1 CONFIRM DRIVE-BY-WIRE CONTROL SYSTEM OPERATES WITH BRAKE OVERRIDE SYSTEM
Yes Go to the applicable DTC inspection.
(Drive-by-wire control system operates with brake override system.)
(See DTC P2299:00 .)
No Go to the next step.
2 INSPECT RELATED PART CONDITION
  • Inspect the following:
  • Fuel quality (such as proper octane, contamination, winter/summer blend)
  • No air leakage from the intake air system
  • No restriction of the intake air system
  • Proper sealing of the intake manifold and components attached to the intake manifold: such as the EGR valve
  • Restriction in the intake air system (such as the air cleaner element, fresh air duct)
  • Vacuum connection
    • Clutch slippage (MTX)
  • Is there any malfunction?
Yes Repair or replace the malfunctioning part according to the inspection results.
Repeat Step 2.
No Go to the next step.
3 VERIFY PCM DTC
Yes Go to the applicable DTC inspection.
(See DTC TABLE .)
No Go to the next step.
4 VERIFY IF MALFUNCTION CAUSE IS OVERHEATING
  • Is the engine overheating?
Yes Go to the symptom troubleshooting "NO. 17 COOLING SYSTEM CONCERNS-OVERHEATING".
(See NO. 17 COOLING SYSTEM CONCERNS-OVERHEATING .)
No Go to the next step.
5 VERIFY CURRENT INPUT SIGNAL STATUS
CAUTION:
  • While performing this step, always operate the vehicle in a safe and lawful manner.
  • When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
  • APP1
  • APP2
  • TP1
  • TP2
  • RPM
  • MAF
  • IAT
  • VPWR
    • VSS
  • Do the PIDs indicate the correct values under the trouble condition? (See PCM INSPECTION .)
Yes Go to the next step.
No APP1, APP2 PIDs are not as specified:

TP1, TP2 PIDs are not as specified:

RPM PID is not as specified:

MAF PID is not as specified:

IAT PID is not as specified:

VPWR PID is not as specified:
  • Inspect for an intermittent open circuit.

VSS PID is not as specified:

Repair or replace the malfunctioning part according to the inspection results.
6 VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
7 VERIFY SPARK PLUG CONDITION
  • Inspect the spark plug condition. (See SPARK PLUG INSPECTION .)
  • Is the spark plug wet, covered with carbon or grayish white?
Yes Spark plug is wet or covered with carbon:
  • Inspect for fuel leakage from fuel injector.

Spark plug is grayish white:
  • Inspect the fuel injector for restriction.

Repair or replace the malfunctioning part according to the inspection results.
No Install the spark plugs on original cylinders, then go to the next step.
8 INSPECT THROTTLE BODY FOR CLOGGING
Yes Clean the throttle valve.
No Go to the next step.
9 INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
10 INSPECT EXHAUST SYSTEM
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
11 INSPECT FUEL LINE PRESSURE
Yes Zero or low:
  • Inspect the fuel pump relay and the fuel pump circuit. (See RELAY INSPECTION .)
  • Inspect the fuel line for restriction.
  • If there is any malfunction:
    • Repair or replace the malfunctioning part according to the inspection results.

High:
No Go to the next step.
12 INSPECT VARIABLE TUMBLE CONTROL OPERATION
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
13 INSPECT VARIABLE INTAKE AIR CONTROL OPERATION
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
14 DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER
NOTE:
  • The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step.
  • Connect the pressure gauges to the A/C low side and high side pressure lines.
  • Turn the A/C on and measure the low side and high side pressures.
  • Are the pressures within the specification? (See REFRIGERANT PRESSURE CHECK .)
Yes Go to the next step.
No If the A/C is always on:
  • Go to the symptom troubleshooting "NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY".

(See NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY .)
For other symptoms:
  • Inspect the following:
  • Refrigerant charging amount
    • Condenser fan operation
  • Repair or replace the malfunctioning part according to the inspection results.
15 INSPECT A/C CUT-OFF CONTROL SYSTEM OPERATION
Yes Inspect the A/C cut-off system components.
Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
16 DETERMINE IF MALFUNCTION CAUSE IS EVAP CONTROL SYSTEM OR OTHER
  • Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from the purge solenoid valve side.
  • Plug the open end of the vacuum hose.
  • Switch the ignition to ON (engine off).
  • Is the engine stall now eliminated?
Yes Inspect the following:

Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
17 VISUALLY INSPECT CMP SENSOR AND PULSE WHEEL
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
18 INSPECT EGR VALVE OPERATION
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
19 INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
20 INSPECT ENGINE COMPRESSION
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
21 INSPECT IF MALFUNCTION CAUSE IS PCV VALVE OR OTHER
Yes Replace the PCV valve and the oil separator as a single unit, then go to the next step.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION .)
No Inspect the following:
  • Valve timing
  • Internal transaxle part
  • Brake system for dragging

Repair or replace the malfunctioning part according to the inspection results.
22 Verify test results.
  • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX .)
  • If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.
  • If the vehicle is repaired, troubleshooting is completed.
    • If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.