NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [WL-C, WE-C]

12	LACK/LOSS OF POWER-ACCELERATION CRUISE
DESCRIPTION	• Performance is poor under load (e.g., power down when climbing hills).
POSSIBLE CAUSE	• Poor fuel quality • Air leakage from intake-air system • Intake-air system restriction or clogging • Engine overheating • A/C system improper operation • Improper operation of A/C cut-off control • Variable boost control (VBC) system malfunction • EGR system malfunction • Vacuum leakage • Clutch slippage • Exhaust system and/or oxidation catalytic converter restriction • Fuel line or clogging or restriction • Fuel filter clogging or restriction • Fuel inlet-filter clogging or restriction • Incorrect fuel injection timing • Erratic signal from CKP sensor • Erratic signal from CMP sensor • ECT sensor or related circuit malfunction • Boost sensor or related circuit malfunction • Accelerator pedal position (APP) sensor or related circuit malfunction • MAF sensor/IAT sensor No.2 or related circuit malfunction • IAT sensor No.1 or related circuit malfunction • Incorrect idle speed • Inadequate fuel pressure • Fuel pressure sensor or related circuit malfunction • Fuel pressure limiter malfunction (built-in common rail) • Supply pump malfunction • Fuel injector malfunction • Low engine compression • Improper valve timing • Cooling fan seat is improper • Turbocharger malfunction • Charge air cooler malfunction • Brake system dragging • Intake shutter valve malfunction • Guide blade valve malfunction Warning The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services: • Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. • Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.

LACK/LOSS OF POWER-ACCELERATION CRUISE

DESCRIPTION

• Performance is poor under load (e.g., power down when climbing hills).

POSSIBLE CAUSE

• Poor fuel quality

• Air leakage from intake-air system

• Intake-air system restriction or clogging

• Engine overheating

• A/C system improper operation

• Improper operation of A/C cut-off control

• Variable boost control (VBC) system malfunction

• EGR system malfunction

• Vacuum leakage

• Clutch slippage

• Exhaust system and/or oxidation catalytic converter restriction

• Fuel line or clogging or restriction

• Fuel filter clogging or restriction

• Fuel inlet-filter clogging or restriction

• Incorrect fuel injection timing

• Erratic signal from CKP sensor

• Erratic signal from CMP sensor

• ECT sensor or related circuit malfunction

• Boost sensor or related circuit malfunction

• Accelerator pedal position (APP) sensor or related circuit malfunction

• MAF sensor/IAT sensor No.2 or related circuit malfunction

• IAT sensor No.1 or related circuit malfunction

• Incorrect idle speed

• Inadequate fuel pressure

• Fuel pressure sensor or related circuit malfunction

• Fuel pressure limiter malfunction (built-in common rail)

• Supply pump malfunction

• Fuel injector malfunction

• Low engine compression

• Improper valve timing

• Cooling fan seat is improper

• Turbocharger malfunction

• Charge air cooler malfunction

• Brake system dragging

• Intake shutter valve malfunction

• Guide blade valve malfunction

Warning

The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:

• Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.

• Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.

STEP	INSPECTION	RESULTS	ACTION
1	Is the idle speed stable?	Yes	Go to the next step.
No	Go to the symptom troubleshooting “NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [WL-C, WE-C]”.
2	Is the engine overheating?	Yes	Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [WL-C, WE-C]”.
No	Go to the next step.
3	Perform the self-test function using the M-MDS. Turn the engine switch to the ON position (Engine off). Retrieve any DTCs. Are any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC test. (See DTC TABLE [WL-C, WE-C (Thailand, General (L.H.D. R.H.D.) specs.)].) Communication error message is displayed: Inspect the following: • Open circuit between main relay and PCM terminal 201, 203, 205 • Open circuit main relay and PCM terminal 219 • Main relay stuck open • Open or poor ground circuit (PCM terminal 202, 204, 206) • Poor connection to vehicle body ground
No	No DTC is displayed: Go to the next step.
4	Inspect the following: • Fuel quality (e.g.: including water contamination, winter/summer blend) • Fuel line/fuel filter clogging and/or restriction • Fuel inlet-filter clogging and/or restriction • Intake-air system restriction • Exhaust system and/or oxidation catalytic converter restriction • Charge air cooler condition (restriction or damaged) • Vacuum leakage • Cooling fan seat Are all items normal?	Yes	Go to the next step.
No	Service if necessary. Repeat Step 5.
5	Inspect the intake shutter valve operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [WL-C, WE-C].) Is there any malfunction?	Yes	Repair or replace if necessary.
No	Go to the next step.
6	Inspect the guide blade valve operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [WL-C, WE-C].) Is there any malfunction?	Yes	Repair or replace if necessary.
No	Go to the next step.
7	Inspect the A/C cut-off operation. Does the A/C cut-off work properly?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to A/C cut-off system inspection results.
8	Inspect the hose bands between the following parts: • Turbocharger compressor housing and air cleaner • Turbocharger compressor housing and charge air cooler Are the hose bands loose?	Yes	Retighten the hose bands. If the concern is resolved, the inspection is complete. If the concern still exists, go to the next step.
No	Go to the next step.
9	Inspect for improper operation, kinks, clogging or disconnection on guide blade actuator. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [WL-C, WE-C].) Is actuator normal?	Yes	Go to the next step.
No	Repair or replace if necessary. If the concern is resolved, the inspection is complete. If the concern still exists, the turbocharger is normal. Go to the next step.
10	Remove parts necessary to inspect the turbocharger. Do not remove the turbocharger. Inspect if the turbocharger compressor wheel is bent, damaged, or interfering with the housing on vehicle. Is there any malfunction?	Yes	Replace the turbocharger.
No	Go to the next step.
11	Inspect if the turbocharger compressor wheel locknut is loose or has fallen down inside the turbocharger. Is there any malfunction?	Yes	Replace the turbocharger.
No	Go to the next step.
12	Inspect if turbocharger compressor wheel by hand. Does wheel turn easily and smoothly?	Yes	Go to the next step.
No	Replace the turbocharger.
13	Inspect if turbocharger turbine wheel is damaged, cracked or interfering with the housing on the vehicle. Note • Inspect all fins on each turbine wheel. Is there any malfunction?	Yes	Replace the turbocharger.
No	Go to the next step.
14	Is any engine oil found inside the turbocharger turbine housing?	Yes	Excessive amount of oil is found: Replace the turbocharger. Small amount of oil is found: Wipe oil off of the vehicle, then go to the next step.
No	Go to the next step.
15	Is any engine oil found inside the turbocharger compressor housing?	Yes	Wipe oil off of vehicle and install all removed parts in Step 11. Then, go to the next step.
No	Turbocharger is normal. Install all the parts removed in Step11. Then, go to the next step.
16	Perform the EGR system inspection. Is the EGR system normal?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to the EGR system operation results.
17	Inspect idle speed. (See ENGINE TUNE-UP [WL-C, WE-C].) Is the idle speed correct?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to the idle speed inspection results.
18	Inspect the APP sensor. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [WL-C, WE-C].) Is the APP sensor normal?	Yes	Go to the next step.
No	Replace the accelerator pedal component.
19	Visually inspect the CKP sensor and the teeth of the pulse wheel. Are the CKP sensor and the teeth of the pulse wheel normal?	Yes	Go to the next step.
No	Replace the malfunctioning parts.
20	Inspect the CKP sensor. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [WL-C, WE-C].) (See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [WL-C, WE-C].) Is the CKP sensor normal?	Yes	Go to the next step.
No	Replace the CKP sensor. Then go to the next step.
21	Visually inspect the CMP sensor and the teeth of the pulse wheel. Are the CMP sensor and the teeth of the pulse wheel normal?	Yes	Inspect the following PIDs: (See PCM INSPECTION (Thailand, General (L.H.D. R.H.D.) specs.) [WL-C, WE-C].) • ECT • IAT • MAF • MAP • RPM If the PID value is not as specified, repair or replace malfunctioning parts. If the PID value is normal, go to the next step.
No	Replace malfunctioning parts.
22	Inspect the fuel pressure sensor. (See FUEL PRESSURE SENSOR INSPECTION [WL-C, WE-C].) Is the fuel pressure normal?	Yes	Go to the next step.
No	Replace the common rail.
23	Is the engine compression correct? (See COMPRESSION INSPECTION [WL-C, WE-C].)	Yes	Go to the next step.
No	Inspect the following: • Damaged valve seat • Worn valve stem and valve guide • Worn or stuck piston ring • Worn piston, piston ring or cylinder • Improper valve timing Service if necessary.
24	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [WL-C, WE-C].) Is fuel injector normal?	Yes	Go to the next step.
No	Repair or replace if necessary. (See FUEL INJECTOR REMOVAL/INSTALLATION [WL-C, WE-C].)
25	Inspect the timing belt for the following: • Chipping of gear teeth • Low tension • Breakage damage or cracks Is the timing belt normal?	Yes	Inspect the following: • Clutch slippage • CKP sensor • Boost sensor and related circuit • Brake system for dragging If normal, remove and inspect the supply pump and common rail.
No	If the valve timing is incorrect, adjust the valve timing. If the timing belt is not normal, replace the timing belt.
26	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [WL-C, WE-C].) • If the malfunction remains, inspect the related Service Information and perform repair or diagnosis. ― If the vehicle is repaired, troubleshooting completed. ― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if later calibration is available. Retest.

STEP

INSPECTION

RESULTS

ACTION

Is the idle speed stable?

Yes

Go to the next step.

Go to the symptom troubleshooting “NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [WL-C, WE-C]”.

Is the engine overheating?

Yes

Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [WL-C, WE-C]”.

Go to the next step.

Perform the self-test function using the M-MDS.

Turn the engine switch to the ON position (Engine off).

Retrieve any DTCs.

Are any DTCs displayed?

Yes

DTC is displayed:

Go to the appropriate DTC test.

(See DTC TABLE [WL-C, WE-C (Thailand, General (L.H.D. R.H.D.) specs.)].)

Communication error message is displayed:

Inspect the following:

• Open circuit between main relay and PCM terminal 201, 203, 205

• Open circuit main relay and PCM terminal 219

• Main relay stuck open

• Open or poor ground circuit (PCM terminal 202, 204, 206)

• Poor connection to vehicle body ground

No DTC is displayed:

Go to the next step.

Inspect the following:

• Fuel quality (e.g.: including water contamination, winter/summer blend)

• Fuel line/fuel filter clogging and/or restriction

• Fuel inlet-filter clogging and/or restriction

• Intake-air system restriction

• Exhaust system and/or oxidation catalytic converter restriction

• Charge air cooler condition (restriction or damaged)

• Vacuum leakage

• Cooling fan seat

Are all items normal?

Yes

Go to the next step.

Service if necessary.

Repeat Step 5.

Inspect the intake shutter valve operation.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [WL-C, WE-C].)

Is there any malfunction?

Yes

Repair or replace if necessary.

Go to the next step.

Inspect the guide blade valve operation.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [WL-C, WE-C].)

Is there any malfunction?

Yes

Repair or replace if necessary.

Go to the next step.

Inspect the A/C cut-off operation.

Does the A/C cut-off work properly?

Yes

Go to the next step.

Repair or replace the malfunctioning part according to A/C cut-off system inspection results.

Inspect the hose bands between the following parts:

• Turbocharger compressor housing and air cleaner

• Turbocharger compressor housing and charge air cooler

Are the hose bands loose?

Yes

Retighten the hose bands.

If the concern is resolved, the inspection is complete.

If the concern still exists, go to the next step.

Go to the next step.

Inspect for improper operation, kinks, clogging or disconnection on guide blade actuator.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [WL-C, WE-C].)

Is actuator normal?

Yes

Go to the next step.

Repair or replace if necessary.

If the concern is resolved, the inspection is complete.

If the concern still exists, the turbocharger is normal.

Go to the next step.

Remove parts necessary to inspect the turbocharger.

Do not remove the turbocharger.

Inspect if the turbocharger compressor wheel is bent, damaged, or interfering with the housing on vehicle.

Is there any malfunction?

Yes

Replace the turbocharger.

Go to the next step.

Inspect if the turbocharger compressor wheel locknut is loose or has fallen down inside the turbocharger.

Is there any malfunction?

Yes

Replace the turbocharger.

Go to the next step.

Inspect if turbocharger compressor wheel by hand.

Does wheel turn easily and smoothly?

Yes

Go to the next step.

Replace the turbocharger.

Inspect if turbocharger turbine wheel is damaged, cracked or interfering with the housing on the vehicle.

Note

• Inspect all fins on each turbine wheel.

Is there any malfunction?

Yes

Replace the turbocharger.

Go to the next step.

Is any engine oil found inside the turbocharger turbine housing?

Yes

Excessive amount of oil is found:

Replace the turbocharger.

Small amount of oil is found:

Wipe oil off of the vehicle, then go to the next step.

Go to the next step.

Is any engine oil found inside the turbocharger compressor housing?

Yes

Wipe oil off of vehicle and install all removed parts in Step 11. Then, go to the next step.

Turbocharger is normal.

Install all the parts removed in Step11.

Then, go to the next step.

Perform the EGR system inspection.

Is the EGR system normal?

Yes

Go to the next step.

Repair or replace the malfunctioning part according to the EGR system operation results.

Inspect idle speed.

(See ENGINE TUNE-UP [WL-C, WE-C].)

Is the idle speed correct?

Yes

Go to the next step.

Repair or replace the malfunctioning part according to the idle speed inspection results.

Inspect the APP sensor.

(See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [WL-C, WE-C].)

Is the APP sensor normal?

Yes

Go to the next step.

Replace the accelerator pedal component.

Visually inspect the CKP sensor and the teeth of the pulse wheel.

Are the CKP sensor and the teeth of the pulse wheel normal?

Yes

Go to the next step.

Replace the malfunctioning parts.

Inspect the CKP sensor.

(See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [WL-C, WE-C].)

(See CRANKSHAFT POSITION (CKP) SENSOR REMOVAL/INSTALLATION [WL-C, WE-C].)

Is the CKP sensor normal?

Yes

Go to the next step.

Replace the CKP sensor.

Then go to the next step.

Visually inspect the CMP sensor and the teeth of the pulse wheel.

Are the CMP sensor and the teeth of the pulse wheel normal?

Yes

Inspect the following PIDs:

(See PCM INSPECTION (Thailand, General (L.H.D. R.H.D.) specs.) [WL-C, WE-C].)

• ECT

• IAT

• MAF

• MAP

• RPM

If the PID value is not as specified, repair or replace malfunctioning parts.

If the PID value is normal, go to the next step.

Replace malfunctioning parts.

Inspect the fuel pressure sensor.

(See FUEL PRESSURE SENSOR INSPECTION [WL-C, WE-C].)

Is the fuel pressure normal?

Yes

Go to the next step.

Replace the common rail.

Is the engine compression correct?

(See COMPRESSION INSPECTION [WL-C, WE-C].)

Yes

Go to the next step.

Inspect the following:

• Damaged valve seat

• Worn valve stem and valve guide

• Worn or stuck piston ring

• Worn piston, piston ring or cylinder

• Improper valve timing

Service if necessary.

Inspect the fuel injector.

(See FUEL INJECTOR INSPECTION [WL-C, WE-C].)

Is fuel injector normal?

Yes

Go to the next step.

Repair or replace if necessary.

(See FUEL INJECTOR REMOVAL/INSTALLATION [WL-C, WE-C].)

Inspect the timing belt for the following:

• Chipping of gear teeth

• Low tension

• Breakage damage or cracks

Is the timing belt normal?

Yes

Inspect the following:

• Clutch slippage

• CKP sensor

• Boost sensor and related circuit

• Brake system for dragging

If normal, remove and inspect the supply pump and common rail.

If the valve timing is incorrect, adjust the valve timing.

If the timing belt is not normal, replace the timing belt.

Verify test results.

• If normal, return to the diagnostic index to service any additional symptoms.

(See SYMPTOM DIAGNOSTIC INDEX [WL-C, WE-C].)

• If the malfunction remains, inspect the related Service Information and perform repair or diagnosis.

― If the vehicle is repaired, troubleshooting completed.

― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if later calibration is available. Retest.