Symptom Troubleshooting - Engine - (Lf, L3): Diagnosis

SYMPTOM TROUBLESHOOTING WIRING DIAGRAM [LF, L3]

IMPORTANT

Be aware that Oxygen sensor terminology differs between California models (3 O2 sensors) and Non-California models (2 O2 sensors). When testing/servicing oxygen sensors, refer to SYSTEM WIRING DIAGRAMS article to properly identify appropriate sensor.

California Emission Regulation Applicable Model with LF ATX

Scheme 1

Scheme 2

California Emission Regulation Applicable Model with LF MTX, L3

Scheme 3

Except for California Emission Regulation Applicable Model with LF ATX

Scheme 4

Except for California Emission Regulation Applicable Model with LF MTX, L3

Scheme 5

Scheme 6

Scheme 7

Scheme 7: FOREWORD [LF, L3]

When the customer reports a vehicle malfunction, check the malfunction indicator lamp (MIL) indication and diagnostic trouble code (DTC), then diagnose the malfunction according to the following flowchart: If a DTC exists, diagnose the applicable DTC inspection. (See «DTC TABLE [LF, L3]»(ref-345244-S27941921642009102000000) .) If no DTC exists and the MIL does not illuminate or flash, diagnose the applicable symptom troubleshooting. (See «QUICK DIAGNOSTIC CHART [LF, L3]»(ref-345223-S16752353372009102000000) ).

ENGINE SYMPTOM TROUBLESHOOTING [LF, L3]

Confirm trouble symptom using the following diagnostic index, then go to appropriate troubleshooting chart.

No.	TROUBLESHOOTING ITEM		DESCRIPTION	ACTION
1	Melting of main or other fuses			(See NO.1 MELTING OF MAIN OR OTHER FUSES [LF, L3] ).
2	MIL illuminates		The MIL is illuminated incorrectly.	(See NO.2 MIL ILLUMINATES [LF, L3] ).
3	Will not crank		The starter does not work.	(See NO.3 WILL NOT CRANK [LF, L3] ).
4	Hard to start/long crank/erratic start/erratic crank		The starter cranks the engine at normal speed but the engine requires excessive cranking time before starting.	(See NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK [LF, L3] ).
5	Engine stalls.	After start/at idle	The engine stops unexpectedly at idle and/or after start or both.	(See NO.5 ENGINE STALLS-AFTER START/AT IDLE [LF, L3] ).
6	Cranks normally but will not start		The starter cranks engine at normal speed but the engine will not run.	(See NO.6 CRANKS NORMALLY BUT WILL NOT START [LF, L3] ).
7	Slow return to idle		The engine takes more time than normal to return to idle speed.	(See NO.7 SLOW RETURN TO IDLE [LF, L3] ).
8	Engine runs rough/rolling idle		The engine speed fluctuates between the specified idle speed and lower speed and the engine shakes excessively.	(See NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [LF, L3] ).
9	Fast idle/runs on		The engine speed continues at fast idle after warm-up. The engine runs after the ignition switch is turned off.	(See NO.9 FAST IDLE/RUNS ON [LF, L3] ).
10	Low idle/stalls during deceleration		The engine stops unexpectedly at the beginning of deceleration or recovery from deceleration.	(See NO.10 LOW IDLE/STALLS DURING DECELERATION [LF, L3] ).
11	Engine stalls/quits.	Acceleration/cruise	The engine stops unexpectedly at the beginning of acceleration or during acceleration. The engine stops unexpectedly while cruising.	(See NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, SURGES [LF, L3] ).
	Engine runs rough.	Acceleration/cruise	The engine speed fluctuates during acceleration or cruising.
	Misses	Acceleration/cruise	The engine misses during acceleration or cruising.
	Buck/jerk	Acceleration/cruise/deceleration	The vehicle bucks/jerks during acceleration, cruising, or deceleration.
	Hesitation/stumble	Acceleration	A momentary pause at the beginning of acceleration or during acceleration.
	Surges	Acceleration/cruise	A momentary minor irregularity in engine output.
12	Lack/loss of power	Acceleration/cruise	The performance is poor under load (such as power down when climbing ills).	(See NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [LF, L3] ).
13	Knocking/pinging	Acceleration/cruise	Sound is produced when the air/fuel mixture is ignited by something other than the spark plug (such as hot spot in combustion chamber).	(See NO.13 KNOCKING/PINGING/DETONATION-ACCELERATION/CRUISE [LF, L3] ).
14	Poor fuel economy		The fuel economy is unsatisfactory.	(See NO.14 POOR FUEL ECONOMY [LF, L3] ).
15	Emission compliance		Fails emissions test.	(See NO.15 EMISSION COMPLIANCE [LF, L3] ).
16	High oil consumption/leakage		The oil consumption is excessive.	(See NO.16 HIGH OIL CONSUMPTION/LEAKAGE [LF, L3] ).
17	Cooling system concerns	Overheating	The engine runs at higher than normal temperature/overheats.	(See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [LF, L3] ).
18	Cooling system concerns	Runs cold	The engine does not reach normal operating temperature.	(See NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [LF, L3] ).
19	Exhaust smoke		Blue, black, or white smoke from exhaust system	(See NO.19 EXHAUST SMOKE [LF, L3] ).
20	Fuel odor (in engine compartment)		Gasoline fuel smell or visible leakage	(See NO.20 FUEL ODOR (IN ENGINE COMPARTMENT)[LF, L3] ).
21	Engine noise		Engine noise from under hood	(See NO.21 ENGINE NOISE [LF, L3] ).
22	Vibration concerns (engine)		Vibration from under hood or driveline	(See NO.22 VIBRATION CONCERNS (ENGINE)[LF, L3] ).
23	A/C does not work sufficiently.		The A/C compressor magnetic clutch does not engage when A/C is turned on.	(See NO.23 A/C DOES NOT WORK SUFFICIENTLY [LF, L3] ).
24	A/C is always on or A/C compressor runs continuously.		The A/C compressor magnetic clutch does not disengage.	(See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [LF, L3] ).
25	A/C is not cut off under WOT conditions.		The A/C compressor magnetic clutch does not disengage under wide open throttle.	(See NO.25 A/C DOES NOT CUT OFF UNDER WIDE OPEN THROTTLE CONDITIONS [LF, L3] ).
26	Exhaust sulphur smell		Rotten egg smell (sulphur) from exhaust	(See NO.26 EXHAUST SULPHUR SMELL [LF, L3] ).
27	Fuel refill concerns		The fuel tank does not fill smoothly.	(See NO.27 FUEL REFILL CONCERNS [LF, L3] ).
28	Fuel filling shut off issues		The fuel does not shut off properly.	(See NO.28 FUEL FILLING SHUT OFF CONCERNS [LF, L3] ).
29	Spark plug condition		An incorrect spark plug condition.	(See NO.29 SPARK PLUG CONDITION [LF, L3] ).
30	ATX concerns	Upshift/downshift engagement	ATX concerns not related to engine performance.	(See SYMPTOM TROUBLESHOOTING ITEM TABLE [FN4A-EL] .) (See SYMPTOM TROUBLESHOOTING ITEM TABLE [FS5A-EL] .)

DIAGNOSTIC INDEX

Scheme 8

Scheme 8: QUICK DIAGNOSTIC CHART [LF, L3]

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 12: NO.1 MELTING OF MAIN OR OTHER FUSES [LF, L3]

Damaged fuse	Related wiring harness
MAIN	MAIN fuse Generator Starter
ENGINE	ENGINE fuse Main Relay ENG BAR1 fuse ENG BAR2 fuse ENG BAR3 fuse ENG BAR4 fuse (California emission regulation applicable model) EGI INJ fuse
ENG BAR1	ENG BAR1 fuse PCM (4EAT) Purge solenoid valve Variable intake-air solenoid valve EGR valve Variable tumble solenoid valve OCV MAF/IAT sensor VSS(4EAT) Accelerator pedal position sensor EVAP system leak detection pump ET control relay
ENG BAR2	ENG BAR2 fuse PCM
ENG BAR3	ENG BAR3 fuse Front HO2S heater (California emission regulation applicable model) Middle HO2S heater (California emission regulation applicable model) Rear HO2S heater (except for California emission regulation applicable model)
ENG BAR4 (California emission regulation applicable model)	ENG BAR4 fuse Rear HO2S heater (California emission regulation applicable model)
EGI INJ	EGI INJ fuse Front HO2S heater (except for California emission regulation applicable model) Fuel injectors
IG KEY1	IG KEY1 fuse Ignition switch ENGINE fuse (in PJB)
IG KEY2	IG KEY2 fuse Ignition switch BACK fuse (in PJB)
ENGINE (in PJB)	ENGINE fuse (in PJB) PCM Fuel pump relay Ignition coils Condenser
STARTER	STARTER fuse Starter relay Starter
ENG+B	ENG+B fuse PCM
BTN	BTN fuse OBD fuse (in PJB)
OBD (in PJB)	OBJ fuse (in PJB) DLC-2
F/PUMP	F/PUMP fuse Fuel pump relay ET control relay
FAN	FAN fuse FAN control module
BACK (in PJB)	BACK fuse (in PJB) TR switch

FUSE INSPECTION PROCEDURE

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate the DTC inspection. (See DTC TABLE [LF, L3] .)
1		No	No DTC is displayed: Inspect instrument cluster operation. (See INSTRUMENT CLUSTER INSPECTION .)
2	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	NOTE: The following test should be performed for vehicles with immobilizer system. Go to Step 8 for vehicles without immobilizer system. Connect the M-MDS to the DLC-2.Do the following conditions appear? The engine is not completely started. DTC P1260 is displayed.	Yes	Both conditions appear: Go to Step 4.
1		No	Either or other condition appears: Go to the next step.
2	Is the coil connector securely connected to the coil?	Yes	Go to the next step.
2	Is the coil connector securely connected to the coil?	No	Connect the coil connector securely. Return to Step 1.
3	Does the security light flush?	Yes	Go to the next step.
3	Does the security light flush?	No	Inspect instrument cluster and wiring harness. (See INSTRUMENT CLUSTER INSPECTION .)
4	Connect the M-MDS to the DLC-2 and retrieve DTC. DTC B1213, B2139, B2141, B1600, B1601, B1602, B1681, B2103, B2431, U2510	Yes	Go to appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
4		No	Go to the next step.
5	Inspect for the following wiring harnesses and connectors: Between coil terminal A and instrument cluster terminal 2Q Between coil terminal B and instrument cluster terminal 2S Is there any malfunction?	Yes	Repair or replace suspected wiring harness and connector.
5		No	Go to the next step.
6	Inspect for the following wiring harnesses and connectors: Between PCM terminal 1AI and instrument cluster terminal 11 Between PCM terminal 1AM and instrument cluster terminal 1K Is there any malfunction?	Yes	Repair or replace suspected wiring harness and connector.
6		No	Go to the next step.
7	Inspect the following: Battery connection Battery condition (See BATTERY INSPECTION [LF, L3] .) Fuses (See NO.1 MELTING OF MAIN OR OTHER FUSES [LF, L3] .) Transmission is in Park or Neutral. (ATX) Are all items normal?	Yes	Go to the next step.
7		No	Service if necessary. Repeat Step 7.
8	Is clicking sound heard from starter when the ignition switch is turned to START?	Yes	Go to step 13.
8		No	ATX: Go to the next step. MTX: Go to step 10.
9	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON Position. (Engine off) Access TR PID. Is TR PID indicated P/N when selecting P or N position	Yes	Go to step 11.
9		No	Inspect Tr switch is adjusted properly, inspect for an open or short circuit between TR switch and TCM. Repair or replace components as required, Then repeat step 8.
10	INSPECT STARTER INTERLOCK SWITCH Inspect the starter interlock switch Is starter interlock normal?	Yes	Go to the next step.
10		No	Inspect starter interlock switch and related wiring harnesses. Repair or replace components as required. Then repeat step 8.
11	Inspect the starter relay and following harnesses. Between starter relay and PCM Between starter relay and ignition switch (See RELAY INSPECTION .) Are they normal?	Yes	Go to the next step.
11		No	Repair or replace components as required. Then repeat step 8
12	Inspect IGNITION switch and related harnesses. (See IGNITION SWITCH INSPECTION .) Are they normal?	Yes	Go to the next step.
12		No	Repair or replace components as required. Then repeat step 8.
13	Inspect the following harnesses. Between starter relay and battery Between starter relay and starter Are they normal?	Yes	Go to the next step.
13		No	Repair or replace as required. Then go to the next step.
14	Inspect the starting system. (See STARTER INSPECTION [LF, L3] .) Is starting system normal?	Yes	Go to the next step.
14		No	Repair or replace components as required.
15	Inspect for seized/hydro locked engine or flywheel. Is ENGINE seized or hydro locked?	Yes	Repair or replace components as required.
15		No	Go to the next step.
16	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC inspection. (See DTC TABLE [LF, L3] .) Communication error message is displayed: Inspect for the following: Open circuit in wiring harness between main relay and PCM terminal 1BE or 1BG (3) , 1O (4) , 1A (5) (ATX) Open circuit in wiring harness between main relay terminal E and PCM terminal 1Q (1) 1AT (2) Main relay is stuck open. Open or short circuit in wiring harness between DLC and PCM terminals 1AM or 1AI Open or poor GND circuit (PCM terminal 1BD (1) , 1AZ (2) , 1BB, 1AZ (1) , 1BD (2) or 1BH) Poor connection of vehicle body GND
16		No	No DTC is displayed: Go to the next step.
17	Retrieve any KOEO DTCs using M-MDS. Are there DTCs displayed during KOEO inspection?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
17		No	No DTC is displayed: Go to the next step.
18	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)
(1) California emission regulation applicable model and Except for California emission regulation applicable LF ATX model (2) Except for California emission regulation applicable LF ATX, L3 model (3) California emission regulation applicable LF ATX model (4) California emission regulation applicable L3 ATX model and Except for California emission regulation applicable L3 ATX model (5) Except for California emission regulation applicable LF ATX model

NOTE
The following test should be performed for vehicles with immobilizer system. Go to Step 8 for vehicles without immobilizer system.

(1)	California emission regulation applicable model and Except for California emission regulation applicable LF ATX model

(2)	Except for California emission regulation applicable LF ATX, L3 model

(3)	California emission regulation applicable LF ATX model

(4)	California emission regulation applicable L3 ATX model and Except for California emission regulation applicable L3 ATX model

(5)	Except for California emission regulation applicable LF ATX model

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Inspect for the following: Vacuum leakage Proper fuel quality (such as proper octane, contamination, winter/summer blend) Loose bands on intake-air system Cracks on intake-air system parts Intake-air system restriction (such as air cleaner element, fresh air duct.) Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
2		No	No DTC is displayed: Go to the next step.
3	Is engine overheating?	Yes	Go to symptom troubleshooting "No. 17 Cooling system concerns - Overheating". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [LF, L3] ).
3	Is engine overheating?	No	Go to the next step.
4	Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Are wiring harness conditions normal?	Yes	Go to the next step.
4		No	Repair the wiring harnesses.
5	Inspect the spark plug conditions. Is 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 clogging.
5		No	Install the spark plugs on original cylinders. Go to the next step.
6	Visually inspect the CKP sensor and teeth of crankshaft pulley. Are the CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
6		No	Replace the malfunctioning part.
7	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
7	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
8	Attempt to start engine at part throttle. Does engine run smoothly at part throttle?	Yes	Inspect the electronic throttle control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ).
8		No	Go to the next step.
9	Install the fuel pressure gauge between the fuel pipe and fuel distributor. Short check connector terminal F/P to body GND using a jumper wiring. Turn the ignition switch to the ON position. Is fuel line pressure correct with ignition switch ON? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
9		No	Zero or low: Inspect the fuel pump relay and the fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
10	Is the fuel line pressure held after ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
10		No	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [LF, L3] .) If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
11	Disconnect a vacuum hose from purge solenoid valve and plug opening end of vacuum hose. Start engine. Is starting condition improved?	Yes	Inspect if the purge solenoid valve is stuck open.
11		No	Go to the next step.
12	Inspect the MAF sensor for following: Contamination MAF sensor terminal B voltage (GND circuit) Is there any contamination?	Yes	Repair or replace the malfunctioning part.
12		No	Go to the next step.
13	Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Replace the suspected part.
13		No	Go to the next step.
14	Inspect engine condition while tapping EGR valve housing. Does engine condition improve?	Yes	Replace the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [LF, L3] .)
14		No	Go to the next step.
15	Inspect the starting system. (See STARTER INSPECTION [LF, L3] .) Is starting system normal?	Yes	Inspect for loose connectors or poor terminal contact. If there is no malfunction, remove EGR valve and visually inspect for mechanically stuck EGR valve.
15		No	Repair or replace components as required.
16	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, Replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DETECTION CONDITION AND POSSIBLE CAUSE

STEP	INSPECTION	RESULTS	ACTION
1	NOTE: The following test should be perform for vehicles with immobilizer system. Go to Step 8 for vehicles without immobilizer system. Connect the M-MDS to the DLC-2.Do the following conditions appear? The engine is not completely started. DTC P1260 is displayed.	Yes	Both conditions appear: Go to Step 3.
1		No	Either or other condition appears: Go to the next step.
2	Does the engine stall after approx. 2 s since the engine is started?	Yes	Go to the next step.
2		No	Immobilizer system is normal. Go to Step 8.
3	Is coil connector securely connected to coil?	Yes	Go to the next step.
3	Is coil connector securely connected to coil?	No	Connect the coil connector securely. Return to Step 2.
4	Turn the ignition switch to the ON position. Does security light flush?	Yes	Go to the next step.
4		No	Inspect the instrument cluster and wiring harness. (See INSTRUMENT CLUSTER INSPECTION .)
5	Connect the M-MDS to the DLC-2 and retrieve DTC. Are any of the following DTCs displayed? DTC B1213, B1600, B1601, B1602, B1681, B2103, B2139, B2141, B2431, U2510	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
5		No	Go to the next step.
6	Inspect for the following wiring harnesses and connectors: Between coil terminal A and instrument cluster terminal 2Q Between coil terminal B and instrument cluster terminal 2S Are there any malfunctions?	Yes	Repair or replace the suspected wiring harness and connector.
6		No	Go to the next step.
7	Inspect for the following wiring harnesses and connectors: Between PCM terminal 1AI and instrument cluster terminal 11 Between PCM terminal 1 AM and instrument cluster terminal 1K Are there any malfunctions?	Yes	Repair or replace the suspected wiring harness and connector.
7		No	Go to the next step.
8	Verify the following: Vacuum connection Air cleaner element No air leakage from intake-air system No restriction of intake-air system Proper sealing of intake manifold and components attached to intake manifold: EGR valve Ignition wiring Fuel quality: proper octane, contamination, winter/summer blend Electrical connections Smooth operation of throttle valve Are all items normal?	Yes	Go to the next step.
8		No	Service if necessary. Repeat Step 8.
9	Connect the M-MDS to the DLC-2. Access the APP1 and APP2 PIDs. Crank the engine with accelerator pedal released. Are the APP1 and APP2 PIDs indicating that the accelerator pedal is in the released position?	Yes	Go to the next step.
9		No	Inspect for the following: APP sensor Wiring harnesses and connectors for following: PCM terminal 1AC (1) 1AL (2) , 1A0 (3) - APP sensor terminal E PCM terminal 1AP (1) , 1Y (2) , 1AP (3) - APP sensor terminal B PCM terminal 1AL (1) , 1AW (2) , 1AL (3) - APP sensor terminal A PCM terminal 1AS (1) 1AA (2) , 1AV (3) - APP sensor terminal C Ignition switch terminal A - APP sensor terminal F APP sensor terminal D - GND
10	Connect the M-MDS to the DLC-2. Access the TP PID. Crank the engine with accelerator pedal released. Are the TP PID indicates the closed throttle position?	Yes	Go to the next step.
10		No	Inspect for the following: TP sensor Wiring harnesses and connectors for following: PCM terminal 2AO (1) 2K (2) , 2AO (3) - TP sensor terminal B PCM terminal 2AK (1) , 2M (2) , 2AK (3) - TP sensor terminal A PCM terminal 2AL (1) , 2I (2) , 2AL (3) - TP sensor terminal C PCM terminal 2AP (1) , 2O (2) 2AP (3) - TP sensor terminal D
11	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC inspection. (See DTC TABLE [LF, L3] .) Communication error message is displayed: Inspect for the following: Open circuit in wiring harness between main relay and PCM terminal 1BE or 1A (ATX) Open main relay GND circuit Main relay is stuck open. Open or short circuit in wiring harness between DLC and PCM terminals 1AM or 1AI Open or poor GND circuit (PCM terminal 1AZ, 1BB, 1BC (2) , 1BD, 1BG, 1BH, 2BB (1) or 2BC (1) ) Poor connection of vehicle body GND
11		No	No DTC is displayed: Go to the next step.
12	Attempt to start engine at part throttle. Does engine run smoothly at part throttle?	Yes	Inspect electronic throttle control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ).
12		No	Go to the next step.
13	Connect the M-MDS to the DLC-2. Access RPM PID. Is RPM PID indicating engine speed during engine cranking?	Yes	Go to the next step.
13		No	Inspect for the following: Open or short circuit in CKP sensor Open or short circuit in wiring harness between CKP sensor terminal C and PCM terminal 2AQ (1) , 2T (2) , 2AQ (3) Open or short circuit in wiring harness between CKP sensor terminal B and PCM terminal 2W (1) , 2U (2) , 2W (3) Open or short circuit in CKP sensor wiring harnesses If CKP sensor and wiring harness are normal, go to the next step.
14	Visually inspect CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
14		No	Replace the malfunctioning part.
15	Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Are wiring harness conditions normal?	Yes	Go to the next step.
15		No	Repair the wiring harnesses.
16	Perform the spark test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is strong blue spark visible at each cylinder?	Yes	Go to the next step. If symptoms occurs with the A/C on, go to Step 23.
16		No	Repair or replace the malfunctioning part according to spark test result.
17	Inspect the spark plug condition. Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from injector. Spark plug is grayish white: Inspect the fuel injector for clogging.
17		No	Install spark plugs on original cylinders. Go to the next step.
18	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
18	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
19	Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Replace the suspected part.
19		No	Go to the next step.
20	Install the fuel pressure gauge between the fuel pipe and the fuel distributor. Short check connector terminal F/P to body GND using a jumper wiring. Turn the ignition switch to the ON position. Is fuel line pressure correct with ignition switch ON? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
20		No	Zero or low: Inspect the fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
21	Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service if necessary. Is fuel line pressure held after ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
21		No	Inspect the fuel injector. If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
22	NOTE: The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect pressure gauges to A/C low and high pressure side lines.Turn A/C on and measure low side and high side pressures.Are pressures within specifications?(See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
22		No	If A/C is always on, go to 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 [LF, L3] ). For other symptoms, inspect the following: Refrigerant charging amount Condenser fan operation
23	Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from purge solenoid side. Plug opening end of vacuum hose. Start the engine. Is the engine stall now eliminated?	Yes	Inspect if purge solenoid valve is stuck open. Inspect evaporative emission control system.
23		No	Go to the next step.
24	Is air leakage felt or heard at intake-air system components while racing the engine to higher speed?	Yes	Repair or replace the malfunctioning part.
24		No	Go to the next step.
25	Inspect the engine condition while tapping EGR valve housing. Does the engine condition improve?	Yes	Replace the EGR valve.
25		No	Go to the next step.
26	Inspect variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does variable valve timing control function properly?	Yes	Go to the next step.
26		No	Repair or replace the malfunctioning parts according to variable valve timing control system operation inspection results.
27	Is the engine compression correct?	Yes	Inspect the valve timing.
27	Is the engine compression correct?	No	Inspect for cause.
28	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. if vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)
(1) California emission regulation applicable model (2) Except for California emission regulation applicable model with LF engine ATX (3) Except for California emission regulation applicable model with LF engine MTX and L3 engine

NOTE
The following test should be perform for vehicles with immobilizer system. Go to Step 8 for vehicles without immobilizer system.

NOTE
The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step.

(1)	California emission regulation applicable model

(2)	Except for California emission regulation applicable model with LF engine ATX

(3)	Except for California emission regulation applicable model with LF engine MTX and L3 engine

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	NOTE: The following test should be perform for vehicles with immobilizer system. Go to Step 8 for vehicles without immobilizer system. Connect the M-MDS to the DLC-2.Do any of the following conditions appear? Engine does not completely start. DTC P1260 is displayed.	Yes	Both conditions appear: Go to Step 3.
1		No	Either or other condition appears: Go to the next step.
2	Does engine stall after approx. 2 s from when it is started?	Yes	Go to the next step.
2		No	Immobilizer system is normal. Go to Step 8.
3	Is the coil connector securely connected to the coil?	Yes	Go to the next step.
3	Is the coil connector securely connected to the coil?	No	Connect the coil connector securely. Return to Step 2.
4	Turn the ignition switch to the ON position. Does the security light flush?	Yes	Go to the next step.
4		No	Inspect the instrument cluster and wiring harness.
5	Connect the M-MDS equivalent to the DLC-2 and retrieve the DTC. Are any of the following DTCs displayed? DTC B1213, B1600, B1601, B1602, B1681, B2103, B2139, B2141, B2431, U2510	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
5		No	Go to the next step.
6	Inspect the following wiring harnesses and connectors: Between coil terminal A and instrument cluster terminal 2Q Between coil terminal B and instrument cluster terminal 2S Is there any malfunction?	Yes	Repair or replace the suspected wiring harness and connector.
6		No	Go to the next step.
7	Inspect the following wiring harnesses and connectors: Between PCM terminal 1AI and instrument cluster terminal 11 Between PCM terminal 1AM and instrument cluster terminal 1K Is there any malfunction?	Yes	Repair or replace the suspected wiring harness and connector.
7		No	Go to the next step.
8	Verify the following: Vacuum connection External fuel shut off or accessory (such as kill switch, alarm) Fuel quality, proper octane, contamination, winter/summer blend No air leakage from intake-air system Intake-air system restriction (such as air cleaner element, fresh air duct) Proper sealing of intake manifold and components attached to intake manifold: EGR valve Ignition wiring Electrical connections Fuses Smooth operation of throttle valve Are all items normal?	Yes	Go to the next step.
8		No	Service if necessary. Repeat Step 8.
9	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .) Communication error message is displayed: Inspect for the following: Open circuit in wiring harness between main relay and PCM terminal 1BE or 1A(ATX) Open main relay GND circuit Open or short circuit in wiring harness between DLC and PCM terminal 1AM or 1AI Main relay is stuck open. Open or poor GND circuit (PCM terminal 1AZ, 1BB, 1BC (2) , 1BD, 1BG, 1BH, 2BB (1) or 2BC (1) ) Poor connection of vehicle body GND
9		No	No DTC is displayed: Go to the next step.
10	Connect the M-MDS to the DLC-2. Access the APP1 and APP2 PIDs. Crank the engine with accelerator pedal released. Are the APP1 and APP2 PIDs indicating that the accelerator pedal is in the released position?	Yes	Go to the next step.
10		No	Inspect for the following: APP sensor Wiring harnesses and connectors for following: PCM terminal 1AC (1) , 1AL (2) , 1AO (3) , - APP sensor terminal E PCM terminal 1AP (1) , 1Y (2) , 1AP (3) - APP sensor terminal B PCM terminal 1AL (1) , 1AW (2) , 1AL (3) - APP sensor terminal A PCM terminal 1AS (1) , 1AA (2) , 1AV (3) - APP sensor terminal C Ignition switch terminal A - APP sensor terminal F APP sensor terminal D - GND
11	Connect the M-MDS to the DLC-2. Access the TP PID. Crank the engine with accelerator pedal released. Are the TP PID indicates the closed throttle position?	Yes	Go to the next step.
11		No	Inspect for the following: TP sensor Wiring harnesses and connectors for following: PCM terminal 2AO (1) , 2K (2) , 2AO (3) - TP sensor terminal B PCM terminal 2AK (1) , 2M (2) , 2AK (3) - TP sensor terminal A PCM terminal 2AL (1) , 2I (2) , 2AL (3) - TP sensor terminal C PCM terminal 2AP (1) , 2O (2) , 2AP (3) - TP sensor terminal D
12	Does the engine start with the throttle valve closed?	Yes	Go to Step 29.
12	Does the engine start with the throttle valve closed?	No	Go to the next step.
13	Will the engine start and run smoothly at part throttle?	Yes	Inspect the electronic throttle control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ).
13	Will the engine start and run smoothly at part throttle?	No	Go to the next step.
14	Connect the M-MDS to the DLC-2. Access RPM PID. Is RPM PID indicating the engine speed when cranking the engine?	Yes	Go to the next step.
14		No	Inspect for the following: Open or short circuit in CKP sensor Open or short circuit in wiring harness between CKP sensor terminal C and PCM terminal 2AQ (1) , 2T (2) , 2AQ (3) Open or short circuit in wiring harness between CKP sensor terminal B and PCM terminal 2W (1) , 2U (2) , 2W (3) Open or short circuit in CKP sensor wiring harnesses If CKP sensor and wiring harness are normal, go to the next step.
15	Visually inspect the CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
15		No	Replace the malfunctioning part.
16	Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Are wiring harness conditions normal?	Yes	Go to the next step.
16		No	Repair the wiring harnesses.
17	Perform the spark test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is strong blue spark visible at each cylinder?	Yes	Go to the next step.
17		No	Repair or replace the malfunctioning part according to spark test result.
18	Inspect the spark plug conditions. Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from injector. Spark plug is grayish white: Inspect the fuel injector for clogging.
18		No	Install the spark plugs on original cylinders. Go to the next step.
19	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
19	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
20	Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Replace the suspected part.
20		No	Go to the next step.
21	Install the fuel pressure gauge between the fuel pipe and the fuel distributor. Short check connector terminal F/P to body GND using a jumper wiring. Turn the ignition switch to the ON position. Is fuel line pressure correct when ignition switch is turned on/off five times? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
21		No	Zero or low: Inspect the fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
22	Visually inspect the fuel injector O-ring and fuel line for fuel leakage. Service if necessary. Is the fuel line pressure held after the ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
22		No	Inspect the fuel injector. If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
23	Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Start the engine. Is starting condition improved?	Yes	Inspect if the purge solenoid valve is stuck open mechanically. Inspect the evaporative emission control system.
23		No	Go to the next step.
24	Is air leakage felt or heard at intake-air system components while racing engine to higher speed?	Yes	Repair or replace the malfunctioning part.
24		No	Go to the next step.
25	Inspect the engine condition while tapping EGR valve housing. Is engine condition improved?	Yes	Replace the EGR valve.
25		No	Go to the next step.
26	Inspect the variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does variable valve timing control function properly?	Yes	Go to the next step.
26		No	Repair or replace the malfunctioning part.
27	Is the engine compression correct?	Yes	Inspect the valve timing.
27	Is the engine compression correct?	No	Inspect for causes.
28	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)
(1) California emission regulation applicable model (2) Except for California emission regulation applicable model with LF engine ATX (3) Except for California emission regulation applicable model with LF engine MTX and L3 engine

NOTE
The following test should be perform for vehicles with immobilizer system. Go to Step 8 for vehicles without immobilizer system.

(1)	California emission regulation applicable model

(2)	Except for California emission regulation applicable model with LF engine ATX

(3)	Except for California emission regulation applicable model with LF engine MTX and L3 engine

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
1		No	No DTC is displayed: Go to the next step.
2	Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [LF, L3] .) (See THERMOSTAT INSPECTION [LF, L3] .) Is thermostat normal?	Yes	ECT and thermostat are normal. Go to the next step.
2		No	Access ECT PID on the M-MDS. Inspect for both ECT PID and temperature gauge on instrument cluster readings. If temperature gauge on instrument cluster indicates normal range but ECT PID is not same as temperature gauge reading, inspect ECT sensor. If temperature gauge on instrument cluster indicates cold range but ECT PID is normal, inspect temperature gauge and heat gauge unit.
3	Is throttle body free of contamination?	Yes	Inspect for air leakage from the intake-air system components while racing the engine to higher speed.
3	Is throttle body free of contamination?	No	Clean or replace throttle body.
4	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Warm up the engine. Idle the engine for 5 min. Is the symptom disappeared?	Yes	Troubleshooting completed. (Cause of this symptom is that the idle learning of electronic throttle control system is not completed.)
1		No	Go to the next step.
2	Verify the following: External fuel shut off or accessory (such as kill switch, alarm) Fuel quality (such as proper octane, contamination, winter/summer blend) No air leakage from intake-air system Proper sealing of intake manifold and components attached to intake manifold: EGR valve Ignition wiring Electrical connections Fuses Smooth operation of throttle valve PCM GND circuit (2BH, 1BH, 1BD, AZ, 1BB) (1) (1BH, 1AZ, 1BD, 1BB) (2) Are all items normal?	Yes	Go to the next step.
2		No	Service if necessary. Repeat Step 2.
3	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
3		No	No DTC is displayed: Go to the next step.
4	Is the engine overheating?	Yes	Go to symptom troubleshooting " NO. 17 COOLING SYSTEM CONCERNS - OVERHEATING ".
4	Is the engine overheating?	No	Go to the next step.
5	Connect the M-MDS to the DLC-2. Access MAF PID. Drive vehicle with monitoring PID. Is MAF PID within specification?	Yes	Go to the next step.
5		No	Inspect for open or short circuit of MAF sensor and related wiring harness.
6	NOTE: The following test is for engine running at rough idle with A/C on. If other symptoms exist, go to the next step. Connect pressure gauge to A/C low and high pressure side lines.Start engine and idle it.Turn the A/C switch on.Measure low side and high side pressures.Are pressures within specifications?(See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
6		No	If the A/C is always on, go to symptom troubleshooting " 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
7	NOTE: The following test is for engine running rough with P/S on. If other symptoms exist, go to the next step. Connect the M-MDS to the DLC-2.Start the engine and idle it.Retrieve any DTCs for EHPASIs there any EH PAS DTC displayed?	Yes	Go to appropriate the DTC inspection. (See DTC TABLE [LF, L3] .)
7		No	Go to the next step.
8	Visually inspect the CKP sensor and teeth of crankshaft pulley. Are the CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
8		No	Replace the malfunctioning part.
9	Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Are wiring harness conditions normal?	Yes	Go to the next step.
9		No	Repair the wiring harnesses.
10	Inspect the spark plug condition. 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 injector. Spark plug is grayish white: Inspect the fuel injector for clogging.
10		No	Install the spark plugs on original cylinders. Go to the next step.
11	Perform the electronic throttle control system operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does the electronic throttle control system function properly?	Yes	Go to the next step.
11		No	Repair or replace the malfunctioning part according to electronic throttle control system operation inspection results.
12	Install fuel pressure gauge between fuel pipe and fuel distributor. Start the engine and run it at idle. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
12		No	Low: Inspect the fuel line for clogging. If there is no malfunction, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
13	Visually inspect for fuel leakage at fuel injector, O-ring, and fuel line. Service if necessary. Does fuel line pressure hold after ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION [LF, L3] )	Yes	Go to the next step.
13		No	Inspect fuel injector. If fuel injector is normal, replace fuel pump unit.
14	Connect the M-MDS to the DLC-2. Start the engine and idle it. Access LONG FT1 PID. Measure LONG FT1 PID at idle. Is PID value between -14% and +14%?	Yes	Go to the next step.
14		No	LONG FT1 PID is out of specification. Less than specification (too rich): Inspect EVAP control system. If system is normal, go to Step 14. Greater than specification (too lean): Inspect for air leakage at intake-air system components. If system is normal, go to the next step.
15	Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Start the engine. Does the engine condition improve?	Yes	Check if purge solenoid valve is stuck open mechanically. Inspect EVAP control system.
15		No	Go to the next step.
16	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
16	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
17	Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Replace the suspected part.
17		No	Go to the next step.
18	Visually inspect the CMP sensor and teeth of camshaft. Are the CMP sensor and teeth of camshaft normal?	Yes	Go to the next step.
18		No	Replace the malfunctioning part.
19	Inspect the engine condition while tapping EGR valve housing. Does the engine condition improve?	Yes	Replace the EGR valve.
19		No	Go to the next step.
20	Inspect variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does variable valve timing control system function properly?	Yes	Go to the next step.
20		No	Repair or replace the malfunctioning part.
21	Is engine compression correct?	Yes	Inspect the valve timing. (See VARIABLE VALVE TIMING ACTUATOR INSPECTION [LF, L3] .)
21	Is engine compression correct?	No	Inspect for causes.
22	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)
(1) California emission regulation applicable model (2) Except for California emission regulation applicable model

NOTE
The following test is for engine running at rough idle with A/C on. If other symptoms exist, go to the next step.

NOTE
The following test is for engine running rough with P/S on. If other symptoms exist, go to the next step.

(1)	California emission regulation applicable model

(2)	Except for California emission regulation applicable model

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Access ECT PID. Start and warm up engine to normal operating temperature. Is ECT PID between 82-112°C {180-234°F} ?	Yes	Go to the next step.
1		No	ECT PID is higher than 112°C {234°F}: Go to symptom troubleshooting " NO. 17 COOLING SYSTEM CONCERNS - OVERHEATING ". ECT PID is less than 82°C {180°F}: Go to symptom troubleshooting " NO. 18 COOLING SYSTEM CONCERNS - RUNS COLD ".
2	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
2		No	No DTC is displayed: Go to the next step.
3	Measure voltages at PCM terminal 1AP, 1R, 10 (MTX) and 1S. (See PCM INSPECTION [LF, L3] .) Are voltage normal?	Yes	Go to the next step.
3		No	If PCM terminal 1AU (1) , 1AP (2) , 1AU (3) voltage is not specified: Inspect A/C switch, refrigerant pressure switch and fan switch. If PCM terminal 1J (1) , 1R (2) , 1J (3) voltage is not specified: Inspect refrigerant pressure switch (middle pressure). If PCM terminal 1D voltage is not specified: Inspect clutch pedal position (CPP) switch. (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [LF, L3] .) If PCM terminal 1X voltage is not specified: Inspect neutral switch (MTX), transaxle range (TR) switch (ATX). (See NEUTRAL SWITCH INSPECTION [LF, L3] .) (See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FN4A-EL] .) (See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FS5A-EL] .)
4	Connect the M-MDS to the DLC-2. Start the engine and idle it. Retrieve any DTCs for EHPAS. Is there any EHPAS DTC displayed?	Yes	DTC is displayed: Go to appropriate DTC inspection.
4		No	No DTC is displayed: Go to the next step.
5	Is there air leakage felt or heard at intake-air system components while racing engine to higher speed?	Yes	Repair or replace parts if necessary.
5		No	Inspect the following: Electronic throttle control system operation Accelerator pedal position sensor
6	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)
(1) California emission regulation applicable model (2) Except for California emission regulation applicable model with LF engine ATX (3) Except for California emission regulation applicable model with LF engine MTX and L3 engine

(1)	California emission regulation applicable model

(2)	Except for California emission regulation applicable model with LF engine ATX

(3)	Except for California emission regulation applicable model with LF engine MTX and L3 engine

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Does the engine idle roughly?	Yes	Go to symptom troubleshooting "No.8 Engine runs rough/rolling idle". (See NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [LF, L3] ).
1	Does the engine idle roughly?	No	Go to the next step.
2	Turn off the A/C switch and fan switch. Does the A/C magnetic clutch engage?	Yes	Go to 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 [LF, L3] ).
2		No	Go to the next step.
3	Verify the following: Proper routing of and no damage to vacuum lines No air leakage from intake-air system Are all items normal?	Yes	Go to the next step.
3		No	Service if necessary. Repeat Step 3.
4	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
4		No	No DTC is displayed: Go to the next step.
5	Perform the electronic throttle control system operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does the electronic throttle control system function properly?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning part according to electronic throttle control system operation inspection results.
6	Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Drive the vehicle. Does the engine condition improve?	Yes	Inspect the evaporative emission control system.
6		No	Go to the next step.
7	Connect the M-MDS to the DLC-2. Access APP1, APP2, TP, MAF and VSS PIDs. Monitor each PID while driving vehicle. (See PCM INSPECTION [LF, L3] .) Are PIDs normal?	Yes	Go to the next step.
7		No	APP1, APP2 PIDs: Inspect the accelerator pedal position sensor. TP PID: Inspect TP sensor. MAF PID: Inspect MAF sensor. VSS PID: Inspect VSS.
8	Measure voltage at PCM terminal 1AU, 10 (MTX), and 1S. (See PCM INSPECTION [LF, L3] .) Are voltages normal?	Yes	Intermittent concern exists. (See INTERMITTENT CONCERN TROUBLESHOOTING [LF, L3] ).
8		No	If PCM terminal 1 AB (1) ,1AU (2) , 1AB (3) voltage is not as specified: Inspect the brake switch. (See BRAKE SWITCH INSPECTION .) If PCM terminal 1D voltage is not as specified: Inspect the clutch pedal position switch. (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [LF, L3] .) If PCM terminal voltage 1X is not as specified: Inspect the neutral switch (MTX). (See NEUTRAL SWITCH INSPECTION [LF, L3] .) Inspect the TR switch (ATX). (See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FN4A-EL] .) (See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FS5A-EL] .)
9	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM INSPECTION [LF, L3] .)
(1) California emission regulation applicable model (2) Except for California emission regulation applicable model with LF engine ATX (3) Except for California emission regulation applicable model with LF engine MTX and L3 engine

(1)	California emission regulation applicable model

(2)	Except for California emission regulation applicable model with LF engine ATX

(3)	Except for California emission regulation applicable model with LF engine MTX and L3 engine

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Verify the following: Vacuum connection Air cleaner element No air leakage from intake-air system No restriction of intake-air system Proper sealing of intake manifold and components attached to intake manifold: such as EGR valve Ignition wiring Fuel quality (such as proper octane, contamination, winter/summer blend) Electrical connections Smooth operation of throttle valve Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
2		No	No DTC is displayed: Go to the next step.
3	Is engine overheating?	Yes	Go to symptom troubleshooting " NO. 17 COOLING SYSTEM CONCERNS - OVERHEATING ".
3	Is engine overheating?	No	Go to the next step.
4	Connect the M-MDS to the DLC-2. Access APP1, APP2, RPM, VPWR, MAF, TP and VSS PIDs. Drive the vehicle with monitoring PIDs. Are PIDs within specifications? (See PCM INSPECTION [LF, L3] .)	Yes	Go to the next step.
4		No	APP1, APP2 PIDs: Inspect if output signal from accelerator pedal position sensor changes smoothly. RPM PID: Inspect the CKP sensor and related wiring harness for vibration or intermittent open/short circuit. VPWR PID: Inspect for open circuit intermittently. MAF PID: Inspect for open circuit of the MAF sensor and related wiring harness intermittently. TP PID: Inspect if output signal from TP sensor changes smoothly. VSS PID: Inspect for open circuit of VSS and related wiring harness intermittently.
5	Visually inspect the CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
5		No	Replace the malfunctioning part.
6	Inspect the spark plug conditions. Is 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 clogging.
6		No	Install the spark plugs on original cylinders. Go to the next step.
7	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
7	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
8	Perform the electronic throttle control system operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does the electronic throttle control system function properly?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to electronic throttle system operation inspection results.
9	Visually inspect deformed exhaust system part. Is there any deformed exhaust system part?	Yes	Replace the suspected part.
9		No	Go to the next step.
10	Install fuel pressure gauge between the fuel pipe and fuel distributor. Short check connector terminal F/P to body GND using a jumper wiring. Turn the ignition switch to the ON position. Is fuel line pressure correct with ignition switch to ON position? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
10		No	Zero or low: Inspect the fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
11	Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service if necessary. Is fuel line pressure held after ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
11		No	Inspect the fuel injector. If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
12	NOTE: The following test is for engine stall with the A/C on. If other symptom exists, go to the next step. Connect a pressure gauge to A/C low and high pressure side lines.Turn the A/C on and measure low side and high side pressure.Are pressures within specifications?(See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
12		No	If the A/C is always on, go to 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 [LF, L3] ). For other symptoms, inspect the following: Refrigerant charging amount Condenser fan operation
13	NOTE: The following test should be performed for symptom with cruise control ON. If other symptoms exist, go to the next step. Inspect cruise control system.Is cruise control system normal?	Yes	Go to the next step.
13		No	Repair or replace the malfunctioning part.
14	Inspect the front HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [LF, L3] .) Is the front HO2S normal?	Yes	Go to the next step.
14		No	Replace the front HO2S. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [LF, L3] .)
15	Inspect the evaporative purge hose between the fuel tank and the purge valve. Does fuel flow into evaporative purge hose?	Yes	Inspect the check valve (two-way). (See FUEL TANK INSPECTION [LF, L3] .)
15		No	Go to the next step.
16	Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from the purge solenoid valve side. Plug opening end of vacuum hose. Drive the vehicle. Does the engine condition improve?	Yes	Go to the next step. Inspect if the purge solenoid valve is stuck open mechanically. Inspect the evaporative emission control system.
16		No	Go to the next step.
17	Visually inspect the CMP sensor and projections of camshaft pulley. Are CMP sensor and projections of camshaft pulley normal?	Yes	Go to the next step.
17		No	Replace the malfunctioning part.
18	Inspect the variable tumble control operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is the variable tumble control normal?	Yes	Go to the next step.
18		No	Repair or replace the malfunctioning part.
19	Inspect the EGR system. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is the EGR system normal?	Yes	Go to the next step.
19		No	Replace the malfunctioning part.
20	Is the engine compression correct?	Yes	Inspect the following: Valve timing Internal transaxle part (ATX) Clutch (MTX) EGR valve (mechanical stuck) Engine mounts Check valve (two-way)
20	Is the engine compression correct?	No	Inspect for cause.
21	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

NOTE
The following test is for engine stall with the A/C on. If other symptom exists, go to the next step.

NOTE
The following test should be performed for symptom with cruise control ON. If other symptoms exist, go to the next step.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Verify the following: Vacuum connection Restriction in intake-air system (such as air cleaner element, fresh air duct) No air leakage from intake-air system No restriction of intake-air system Proper sealing of intake manifold and components attached to intake manifold; such as EGR valve Fuel quality (such as proper octane, contamination, winter/summer blend) Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
2		No	No DTC is displayed: Go to the next step.
3	Is the engine overheating?	Yes	Go to symptom troubleshooting " NO. 17 COOLING SYSTEM CONCERNS - OVERHEATING ".
3	Is the engine overheating?	No	Go to the next step.
4	Connect the M-MDS to the DLC-2. Access APP1, APP2, RPM, MAF, TP, IAT and VSS PIDs. Drive vehicle while monitoring PIDs. Are PIDs within specifications? (See PCM INSPECTION [LF, L3] .)	Yes	Go to the next step.
4		No	APP1, APP2 PIDS: Inspect if output signal accelerator pedal position sensor changes smoothly. RPM PID: Inspect CKP sensor and related wiring harness for vibration or intermittent open/short circuit or both. MAF PID: Inspect for intermittent open circuit of MAF sensor and related wiring harness. TP PID: Inspect if output signal TP sensor changes smoothly. IAT PID: Inspect for air suction in intake-air system. If normal, inspect intermittent short circuit of IAT sensor and related wiring harnesses. VSS PID: Inspect for intermittent open circuit of VSS and related wiring harness.
5	Visually inspect the CKP sensor and teeth of crankshaft pulley. Are the CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
5		No	Replace the malfunctioning part.
6	Inspect the spark plug condition. Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect the fuel injector for fuel leakage. Spark plug is grayish white: Inspect the fuel injector for clogging.
6		No	Install the spark plugs on original cylinders. Go to the next step.
7	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
7	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace PCV valve.
8	Perform electronic throttle control system operation inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does electronic throttle control system function properly?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to electronic throttle control system operation inspection results.
9	Visually inspect deformed exhaust system part. Is there any deformed exhaust system part?	Yes	Replace the suspected part.
9		No	Go to the next step.
10	Install the fuel pressure gauge between the fuel pipe and the fuel distributor. Short check connector terminal F/P to body GND using a jumper wiring. Turn the ignition switch to the ON position. Is fuel line pressure correct with ignition switch to ON position? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
10		No	Zero or low: Inspect the fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
11	Inspect variable tumble control operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does variable tumble control function properly?	Yes	Go to the next step.
11		No	Repair or replace the malfunctioning part.
12	Inspect variable intake-air control operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does VIS function properly?	Yes	Go to the next step.
12		No	Repair or replace the malfunctioning part.
13	NOTE: The following test is for engine stalling with the A/C on concern. If other symptoms exist, go to the next step. Connect pressure gauge to the A/C low and high side pressure lines.Turn the A/C on and measure low side and high side pressures.Are pressures within specifications?(See REFRIGERANT PRESSURE CHECK .)	Yes	Go to the next step.
13		No	If A/C is always on, go to 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 [LF, L3] ). For other symptoms, inspect the following: Refrigerant charging amount Condenser fan operation
14	Inspect for A/C cut-off operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does the A/C cut-off function properly?	Yes	Go to the next step.
14		No	Inspect A/C cut-off system components.
15	Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Drive the vehicle. Does the engine condition improve?	Yes	Inspect if purge solenoid valve is stuck open mechanically. Inspect the evaporative emission control system. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ).
15		No	Go to the next step.
16	Visually inspect the CMP sensor and projections of camshaft pulley. Are the CMP sensor and projections of camshaft pulley normal?	Yes	Go to the next step.
16		No	Replace the malfunctioning part.
17	Inspect EGR system. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is EGR system normal?	Yes	Go to the next step.
17		No	Replace the malfunctioning part according to EGR control system operation inspection results.
18	Inspect the variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does the variable valve timing control system function properly?	Yes	Go to the next step.
18		No	Repair or replace the malfunctioning part according to variable valve timing control system inspection results.
19	Is the engine compression correct?	Yes	Inspect the following: Valve timing Internal transaxle components (ATX) Clutch (MTX) Brake system for dragging
19	Is the engine compression correct?	No	Inspect for cause.
20	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

NOTE
The following test is for engine stalling with the A/C on concern. If other symptoms exist, go to the next step.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Access ECT PID. Verify ECT PID is less than 116°C {241°F} during driving. Is ECT PID less than specification?	Yes	Go to the next step.
1		No	Inspect the cooling system for cause of overheating.
2	Connect the M-MDS to the DLC-2. Access IAT and MAF PIDs. Monitor each PID. (See PCM INSPECTION [LF, L3] .) Are PIDs normal?	Yes	Go to the next step.
2		No	IAT PID: Inspect IAT sensor MAF PID: Inspect MAF sensor
3	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (engine off). Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
3		No	No DTC is displayed: Go to the next step.
4	Is engine compression correct?	Yes	Go to the next step.
4	Is engine compression correct?	No	Inspect for cause.
5	Install fuel pressure gauge between fuel pipe and fuel distributor. Start the engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Inspect the ignition timing.
5		No	Low: Inspect the fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
6	Inspect the knock sensor. Is the knock sensor normal?	Yes	Inspect ignition timing.
6	Inspect the knock sensor. Is the knock sensor normal?	No	Replace the knock sensor.
7	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Inspect for the following: Air cleaner element for contamination ATF level (ATX) Fuel quality Coolant level Brake dragging Clutch slippage (MTX) Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
2		No	No DTC is displayed: Go to the next step.
3	Access ECT PID. Drive vehicle while monitoring PID. (See PCM INSPECTION [LF, L3] .) Is PID within specification?	Yes	Go to the next step.
3		No	Inspect for coolant leakage, cooling fan and condenser fan operations or thermostat operation.
4	Perform the spark test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is strong blue spark visible at each cylinder?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning part according to spark test result.
5	Install the fuel pressure gauge between the fuel pipe and the fuel distributor. Start the engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
5		No	Low: Inspect the fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
6	Inspect for the variable tumble control operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does the variable tumble control function properly?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning part.
7	Inspect for variable valve timing control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does the variable valve timing control system function properly?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part.
8	Inspect for the variable intake-air control operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does variable intake-air control function properly?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part.
9	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
9	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
10	Visually inspect the exhaust system part. Is there any deformed exhaust system?	Yes	Replace the suspected part.
10		No	Go to the next step.
11	Inspect for contaminated MAF sensor. Is there any contamination?	Yes	Go to the next step.
11		No	Inspect for cause.
12	Inspect the MAF sensor for contamination. Is there any contamination?	Yes	Replace MAF sensor.
12		No	Go to the next step.
13	Is engine compression correct?	Yes	Inspect the valve timing.
13	Is engine compression correct?	No	Inspect for cause.
14	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Inspect for the following: Vacuum lines for leakage or blockage Electrical connections Proper maintenance schedule followed Intake-air system and air cleaner element concerns: obstructions, leakage or dirtiness Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
2		No	No DTC is displayed: Go to the next step.
3	Is any other driveability concern present?	Yes	Go to appropriate symptom troubleshooting.
3	Is any other driveability concern present?	No	Go to the next step.
4	Connect the M-MDS to the DLC-2. Access ECT PID. Warm up the engine and idle it. Verify ECT PID is correct. (See PCM INSPECTION [LF, L3] .) Is ECT PID correct?	Yes	Go to the next step.
4		No	Inspect for coolant leakage, cooling fan and condenser fan operation or thermostat operation.
5	Inspect fuel-filler cap. (See FUEL-FILLER CAP INSPECTION [LF, L3] .) Is there any leakage at fuel-filler cap?	Yes	Replace the fuel-filler cap.
5		No	Go to the next step.
6	Inspect the front HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [LF, L3] .) Is front HO2S normal?	Yes	Go to the next step.
6		No	Replace the front HO2S. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [LF, L3] .)
7	Perform spark test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is strong blue spark visible at each cylinder?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to spark test result.
8	Install the fuel pressure gauge between the fuel pipe and the fuel distributor. Start the engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
8		No	Low: Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
9	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
9	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
10	Inspect for fuel saturation inside charcoal canister. Is excess amount of liquid fuel present in canister?	Yes	Replace the charcoal canister.
10		No	Inspect the fuel tank vent system. Then, go to the next step. (See FUEL TANK INSPECTION [LF, L3] .)
11	Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Replace the part.
11		No	Go to the next step.
12	Inspect the three-way catalytic converter. (See EXHAUST SYSTEM INSPECTION [LF, L3] .) Is the three-way catalytic converter normal?	Yes	Inspect the EGR system. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ).
12		No	Replace the three-way catalytic converter.
13	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Go to the next step.
1	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
2	Inspect for the following: External leakage Proper dipstick Proper engine oil viscosity Are all items normal?	Yes	Inspect the internal engine parts such as valves, valve guides, valve stem seals, cylinder head drain passage, and piston rings.
2		No	Service if necessary. Repeat Step 2.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Inspect the following: Engine coolant level Coolant leakage Water and anti-freeze mixture Radiator condition Collapsed or restricted radiator hoses Radiator pressure cap Overflow system Fan rotational direction Fuses Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
2		No	No DTC is displayed: Go to the next step.
3	Start the engine and idle it. Turn the A/C switch on and set blower fan to any speed. Does the A/C compressor engage?	Yes	Go to Step 5.
3		No	Inspect for the following and repair or replace if necessary: Refrigerant charging amount Open circuit in wiring harness between A/C relay and PCM terminal 1I (1) , 1AN (2) , 1I (3) Seized A/C magnetic clutch A/C magnetic clutch malfunction If all items are normal, go to the next step.
4	Start the engine and idle it. Turn the A/C switch on and set blower fan any speed. Measure voltage at PCM terminal 1AP. (See PCM INSPECTION [LF, L3] .) Is voltage normal?	Yes	Go to the next step.
4		No	Inspect the following: Refrigerant pressure switch operation The A/C switch is stuck open. Open or short circuit between refrigerant pressure switch and PCM terminal 1AU (1) , 1AP (2) , 1AU (3) Open circuit of blower motor fan switch and resistor (if blower motor does not operate) The evaporator temperature sensor and A/C amplifier
5	Inspect cooling fan control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does the cooling fan control system function properly?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning part.
6	Is the drive belt normal?	Yes	Go to the next step.
6	Is the drive belt normal?	No	Replace the drive belt.
7	Is there leakage around the heater unit in passenger compartment?	Yes	Inspect and service heater for leakage.
7		No	Go to the next step.
8	Is there leakage at the coolant hoses and/or radiator?	Yes	Replace the malfunctioning part.
8	Is there leakage at the coolant hoses and/or radiator?	No	Go to the next step.
9	Cool down the engine. Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [LF, L3] .) (See THERMOSTAT INSPECTION [LF, L3] .) Is thermostat normal?	Yes	The engine coolant temperature and thermostat are normal, inspect engine block for leakage or blockage.
9		No	Access ECT PID. Inspect for both ECT PID and temperature gauge readings. If temperature gauge on instrument cluster indicates normal range but ECT PID is not same as temperature gauge reading, inspect ECT sensor. If temperature gauge on instrument cluster indicates overheating but ECT PID is normal, inspect temperature gauge and heat gauge unit.
10	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)
(1) California emission regulation applicable model (2) Except for California emission regulation applicable model with LF engine ATX (3) Except for California emission regulation applicable model with LF engine MTX and L3 engine

(1)	California emission regulation applicable model

(2)	Except for California emission regulation applicable model with LF engine ATX

(3)	Except for California emission regulation applicable model with LF engine MTX and L3 engine

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Is customer complaint "Lack of passenger compartment heat" only?	Yes	Inspect A/C and heater system.
1		No	Go to the next step.
2	Does the engine speed continue at fast idle?	Yes	Go to symptom troubleshooting "No.9 Fast idle/runs on". (See NO.9 FAST IDLE/RUNS ON [LF, L3] ).
2	Does the engine speed continue at fast idle?	No	Go to the next step.
3	Remove the thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [LF, L3] .) (See THERMOSTAT INSPECTION [LF, L3] .) Is thermostat normal?	Yes	Go to the next step.
3		No	Replace the thermostat.
4	Inspect cooling fan control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Does the cooling fan control system function properly?	Yes	Access ECT PID. Inspect for both ECT PID and temperature gauge on instrument cluster readings. If the temperature gauge on the instrument cluster indicates normal range but ECT PID is not the same as temperature gauge reading, inspect the ECT sensor. If the temperature gauge on the instrument cluster indicates cold range but ECT PID is normal, inspect the temperature gauge and heat gauge unit.
4		No	Repair or replace the malfunctioning part.
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	What color is smoke coming from the exhaust system?	Blue	Burning oil is indicated. Go to the next step.
		White	Water in combustion is indicated. Go to Step 3.
		Black	Rich fuel mixture is indicated. Go to Step 4.
2	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	Inspect for the following: Damaged valve guide, stems or valve seals Blocked oil drain passage in cylinder head Piston ring is not seated, seized or worn. Damaged cylinder bore If other drivability symptoms are present, return to diagnostic index to service any additional symptoms.
2	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
3	Does the cooling system hold pressure?	Yes	Inspect for the following: Cylinder head gasket leakage Intake manifold gasket leakage Cracked or porous engine block If other drivability symptoms are present, return to diagnostic index to service any additional symptoms.
3	Does the cooling system hold pressure?	No	Inspect for cause.
4	Inspect for the following: Air cleaner restriction Collapsed or restricted intake-air system Restricted fuel return line Are all items normal?	Yes	Go to the next step.
4		No	Service if necessary. Repeat Step 4.
5	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
5		No	No DTC is displayed: Go to the next step.
6	Install the fuel pressure gauge between the fuel pipe and the fuel distributor. Start the engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
6		No	Low: Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
7	Perform the spark test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is strong blue spark visible at each cylinder?	Yes	Inspect the CMP sensor. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [LF, L3] .)
7		No	Repair or replace the malfunctioning part according to spark test result.
8	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service if necessary. Install the fuel pressure gauge between the fuel pipe and the fuel distributor. Start engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
1		No	Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
2	Inspect for blockage/restriction or open circuit in wiring harness between the engine vacuum port and the charcoal canister. Inspect for blockage in fuel tank vent system. Is malfunction indicated?	Yes	Replace vacuum hose.
2		No	Go to the next step.
3	Inspect the purge solenoid valve. (See PURGE SOLENOID VALVE INSPECTION [LF, L3] .) Is the solenoid operating properly?	Yes	Go to the next step.
3		No	Replace the purge solenoid valve. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [LF, L3] .)
4	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
4		No	No DTC is displayed: Inspect charcoal canister for fuel saturation. If excess amount of liquid fuel is present, replace the charcoal canister.
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Is a squealing, click or chirping sound present?	Yes	Inspect for the followings: Engine oil level Drive belt tension Splash shield or under cover looseness Generator installation (alignment)
1	Is a squealing, click or chirping sound present?	No	Go to the next step.
2	Is a rumbling or grinding noise present?	Yes	Inspect for the followings: Drive belt tension P/S fluid level
2	Is a rumbling or grinding noise present?	No	Go to the next step.
3	Is a rattling noise present?	Yes	Inspect rattling location for loose parts.
3	Is a rattling noise present?	No	Go to the next step.
4	Is a hissing noise present?	Yes	Inspect for the following: Vacuum leakage Spark plug looseness Intake-air system leakage
4	Is a hissing noise present?	No	Go to the next step.
5	Is a rapping or roar noise present?	Yes	Inspect looseness for followings: Dynamic dumper Intake-air system Exhaust system
5	Is a rapping or roar noise present?	No	Go to the next step.
6	Is a knocking noise present?	Yes	Go to symptom troubleshooting "No.11 Knocking/pinging". (See NO.13 KNOCKING/PINGING/DETONATION-ACCELERATION/CRUISE [LF, L3] ).
6	Is a knocking noise present?	No	If the noise comes from the engine internal, inspect for friction gear, timing chain or MLA noise.
7	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Inspect the following components for loose attaching bolts or worn parts: Cooling fan Drive belt and pulleys Generator Engine mounts Exhaust system mounts All items normal?	Yes	Inspect the following systems: Wheels ATX Driveline Suspension
1		No	Readjust or retighten engine mount installation position. Service if necessary for other parts.
2	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
1		No	No DTC is displayed: Go to the next step.
2	Disconnect A/C compressor connector. Start engine and turn A/C switch on. Is there correct voltage at A/C compressor magnetic clutch terminal? Specification 10.5 V or more	Yes	Inspect for GND condition of magnetic clutch on A/C compressor. If GND condition is normal, inspect for open circuit magnetic clutch coil.
2		No	Go to the next step.
3	Disconnect refrigerant pressure switch connector. Connect jumper wiring between A/C high pressure switch terminal. Connect jumper wiring between refrigerant pressure switch terminal. Turn the ignition switch to the ON position. Turn A/C switch on and set blower fan to any speed. Does A/C work?	Yes	Inspect refrigerant pressure switch operation. If switch is normal, go to the next step.
3		No	Inspect for the following: A/C switch is stuck open. Open circuit in wiring harness between refrigerant pressure switch and PCM terminal 1AU (1) , 1AP (2) , 1AU (3) Open circuit in wiring harness between blower motor fan switch and resistor (if blower motor does not operate) Evaporator temperature sensor and A/C amplifier
4	Remove jumper wiring from the switch connector. Reconnect connector to refrigerant pressure switch. Start the engine and turn the A/C switch on. Does the fan operate?	Yes	Inspect whether A/C relay is stuck open. Replace if necessary.
4		No	Inspect the following and repair or replace if necessary: Refrigerant charging amount A/C compressor for seizure
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)
(1) California emission regulation applicable model (2) Except for California emission regulation applicable model with LF engine ATX (3) Except for California emission regulation applicable model with LF engine MTX and L3 engine

(1)	California emission regulation applicable model

(2)	Except for California emission regulation applicable model with LF engine ATX

(3)	Except for California emission regulation applicable model with LF engine MTX and L3 engine

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
1		No	No DTC is displayed: Go to the next step.
2	Start the engine and idle it. Turn the A/C switch on. Remove the A/C relay. Does the A/C magnetic clutch disengage?	Yes	Inspect for the following: A/C relay is stuck closed. Short to GND in wiring harness between A/C relay and PCM terminal 1AN. If both items normal, go to the next step.
2		No	Inspect if circuit between the A/C relay and magnetic clutch shorts to battery power circuit. If the circuit is normal, inspect the magnetic clutch for stuck engagement or clearance.
3	Disconnect refrigerant pressure switch connector. Start the engine and turn A/C switch on. NOTE: A/C should not work when disconnecting connector. If A/C remains working, short to GND circuit may be present. Does the A/C remain working?	Yes	Inspect for short to GND in wiring harness between refrigerant pressure switch and PCM terminal 1AU (1) , 1AP (2) , 1AU (3) .
3		No	Go to the next step.
4	Reconnect refrigerant pressure switch connector. Turn off A/C switch. NOTE: A/C should not work when turning A/C switch off. If A/C remains working, short to GND circuit may be present. Does A/C remain working?	Yes	Inspect following: Short to GND in wiring harness between A/C switch and A/C amplifier Short to GND circuit between A/C amplifier and refrigerant pressure switch
4		No	Inspect whether A/C switch is stuck closed.
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)
(1) California emission regulation applicable model (2) Except for California emission regulation applicable model with LF engine ATX (3) Except for California emission regulation applicable model with LF engine MTX and L3 engine

NOTE
A/C should not work when disconnecting connector. If A/C remains working, short to GND circuit may be present.

NOTE
A/C should not work when turning A/C switch off. If A/C remains working, short to GND circuit may be present.

(1)	California emission regulation applicable model

(2)	Except for California emission regulation applicable model with LF engine ATX

(3)	Except for California emission regulation applicable model with LF engine MTX and L3 engine

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Does A/C compressor disengage when the A/C switch is turned off?	Yes	Go to the next step.
1		No	Go to symptom troubleshooting " NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY ".
2	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
2		No	No DTC is displayed: Inspect accelerator pedal position sensor.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Are any drivability or exhaust smoke concerns present?	Yes	Go to the appropriate flow chart.
1	Are any drivability or exhaust smoke concerns present?	No	Go to the next step.
2	Inspect the following: Electrical connections Vacuum lines Fuel quality Are all items normal?	Yes	Go to the next step.
2		No	Service if necessary. Repeat Step 2.
3	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
3		No	No DTC is displayed: Go to the next step.
4	Install the fuel pressure gauge between the fuel pipe and the fuel distributor. Start engine and idle it. Is fuel line pressure correct at idle? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
4		No	Low: Inspect fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
5	Inspect the charcoal canister for fuel saturation. Is excess amount of liquid fuel present in canister?	Yes	Replace the charcoal canister.
5		No	Inspect the fuel tank vent system. If the fuel tank vent system is normal, suggest trying a different brand since sulfur content can vary in different fuels. If the fuel tank vent system is not normal, repair or replace the malfunctioning part.
6	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
1		No	No DTC is displayed: Go to the next step.
2	Remove the fuel-filler pipe. Make sure the nonreturn valve is installed properly. Inspect nonreturn valve operation. Is the nonreturn valve normal?	Yes	Inspect for the following: Improper use of fuel nozzle Inadequate fuel filling speed
2		No	Nonreturn valve is installed improperly: Reinstall nonreturn valve to proper position. Nonreturn valve does not operate properly: Replace nonreturn valve.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF, L3] .)
1		No	No DTC is displayed: Go to the next step.
2	Remove the fuel-filler pipe. Make sure the nonreturn valve is installed properly. Inspect nonreturn valve operation. Is the nonreturn valve normal?	Yes	Inspect for the following: Improper use of fuel nozzle Fuel is not inserted correctly. Inspect fuel shut-off valve.
2		No	Nonreturn valve is installed improperly: Reinstall the nonreturn valve to proper position. Nonreturn valve does not operate properly: Replace the nonreturn valve.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Remove all the spark plugs. Inspect spark plug condition. Is spark plug condition normal?	Yes	Troubleshooting completed.
1		No	Specific plug is wet or covered with carbon: Go to the next step. Specific plug looks grayish white: Go to Step 7. All plugs are wet or covered with carbon: Go to Step 9. All plugs look grayish white: Go to Step 15.
2	Are the spark plug wet/covered with carbon by the engine oil?	Yes	Inspect all areas related to oil, working up and down.
2		No	Go to the next step.
3	Inspect the spark plug for the following: Cracked insulator Heat range Air gap Worn electrode Is the spark plug normal?	Yes	Go to the next step.
3		No	Replace the spark plug. (See SPARK PLUG REMOVAL/INSTALLATION [LF, L3] .)
4	Inspect compression pressure at suspected malfunctioning cylinder. Is compression pressure correct? (See COMPRESSION INSPECTION [LF, L3] .)	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning part.
5	Install all spark plugs. Perform the spark test at suspected malfunctioning cylinder. Is strong blue spark visible? (Compare with normal cylinder.)	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning part.
6	Install the fuel pressure gauge between fuel filter and fuel distributor. Short check connector terminal F/P to body GND using a jumper wiring. Turn the ignition switch to the ON position (Engine off). Is the fuel line pressure correct with the ignition switch at ON? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Inspect fuel injector for the following: Open or short circuit in injector Leakage Injection volume
6		No	Zero or low: Inspect the fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
7	Inspect the spark plug for the following. Heat range Air gap Is the spark plug normal?	Yes	Go to the next step.
7		No	Replace the spark plug. (See SPARK PLUG REMOVAL/INSTALLATION [LF, L3] .)
8	Remove the suspected fuel injector. Inspect the following: Resistance (See FUEL INJECTOR INSPECTION [LF, L3] .) Fuel injection volume (See FUEL INJECTOR INSPECTION [LF, L3] .) Are all above items normal?	Yes	Inspect for open circuit in wiring harness between fuel injector connector terminal A and PCM at the following terminals: For No.1 cylinder: 2AW (1) , 2BB (2) , 2BA (1) , 2BE (2) , 2BA (3) For No.2 cylinder: 2AS (1) , 2BC (2) , 2AW (1) , 2BF (2) , 2AW (3) For No.3 cylinder: 2AX (1) , 2BD (2) , 2AX (1) , 2BG (2) , 2AX (3) For No.4 cylinder: 2AT (1) , 2AZ (2) , 2AT (1) 2BH (2) , 2AT (3)
8		No	Replace the fuel injector.
9	Is the air cleaner element free of clogging?	Yes	Go to the next step.
9	Is the air cleaner element free of clogging?	No	Replace the air cleaner element.
10	Perform the spark test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is strong blue spark visible at each cylinder?	Yes	Go to the next step.
10		No	Repair or replace the malfunctioning part.
11	Install the fuel pressure gauge between the fuel filter and fuel distributor. Short check connector terminal F/P to body GND using a jumper wiring. Turn the ignition switch to the ON position (Engine off). Is the fuel line pressure correct with ignition switch at ON? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Go to the next step.
11		No	Zero or low: Inspect the fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .)
12	Inspect the following PIDs: ECT O2S11 (When engine can be started.) O2S12 (When engine can be started.) O2S13 (1) (When engine can be started.) MAF (See PCM INSPECTION [LF, L3] .) Are PIDs normal?	Yes	Go to the next step.
12		No	Repair or replace the malfunctioning part.
13	Perform the purge control inspection. (When engine can be started.) (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [LF, L3] ). Is the purge control correct?	Yes	Go to the next step.
13		No	Repair or replace the malfunctioning part.
14	Perform compression inspection. (See COMPRESSION INSPECTION [LF, L3] .) Is compression correct?	Yes	Visually inspect for deformed exhaust system part.
14		No	Repair or replace the malfunctioning part.
15	When the engine cannot be started, inspect the intake-air system for air leakage. When the engine can be started, perform intake manifold vacuum inspection. Is air sucked in from intake-air system?	Yes	Repair or replace the malfunctioning part.
15		No	Go to the next step.
16	Install the fuel pressure gauge between the fuel filter and the fuel distributor. Short check connector terminal F/P to body GND using a jumper wiring. Turn the ignition switch to the ON position (Engine off). Is fuel line pressure correct with the ignition switch at ON? (See FUEL LINE PRESSURE INSPECTION [LF, L3] .)	Yes	Inspect the following PIDs: ECT O2S11 O2S12 O2S13 (1) MAF (See PCM INSPECTION [LF, L3] .) Inspect PCM GND condition.
16		No	Zero or low: Inspect the fuel pump relay and fuel pump circuit. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF, L3] )
17	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [LF, L3] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF, L3] .)
(1) California emission regulation applicable model (2) Except for California emission regulation applicable model with LF engine ATX (3) Except for California emission regulation applicable model with LF engine MTX and L3 engine

(1)	California emission regulation applicable model

(2)	Except for California emission regulation applicable model with LF engine ATX

(3)	Except for California emission regulation applicable model with LF engine MTX and L3 engine

DIAGNOSTIC PROCEDURE

Inspection Method for Sensors

Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position (Engine off). NOTE: If the engine starts and runs, perform the following steps during idle.
Access PIDs for the switch you are inspecting.
Vibrate the sensor slightly with your finger. If PID value is unstable or malfunction occurs, check for poor connection or poorly mounted sensor or both.

Scheme 13

Scheme 13: Inspection Method for Actuators or Relays

Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position (Engine off). NOTE: If the engine starts and runs, perform the following steps during idle.
Prepare the output state control function for actuators or relays that you are inspecting.
Vibrate the actuator or relay with your finger for 3 s after output state control function is activated. If variable click sound is heard, check for poor connection or poorly mounted actuator or both, or the relay. NOTE: Vibrating relays too strongly may result in open relays.

Input Signal System Inspection Procedure

Find an irregular signal.(See «FINDING IRREGULAR SIGNALS»(ref-345223-S36275091382009102000000) ).
Locate source. (See «LOCATING THE SOURCE OF UNUSUAL SIGNALS»(ref-345223-S05884911012009102000000) ).
Repair or replace the malfunctioning part.
Confirm that the irregular signal is no longer detected.

Input signal system inspection for variable resistance type 1

When an irregular signal is detected, measure the #1 PCM terminal voltage. If the #1 terminal voltage and the M-MDS monitor voltage are the same, proceed to the next step. If there is a difference of 0.5 V or more, inspect for the following points concerning the PCM connector: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected.
Measure the #2 sensor terminal voltage. If there is a 0.5 V or more difference between the sensor and the M-MDS voltages, inspect the wiring harness for open or short circuits. If the sensor and the M-MDS voltages are the same, inspect for the following points concerning the sensor connector: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) If there are no problems, proceed to next investigation below.

Standard power supply system inspection for variable resistance type 1

Confirm that the #3 terminal is at 5 V. If the measured voltage on the #3 terminal is 5 V, inspect the following points on the sensor connector. If there is no problem, inspect for the following: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) If the #3 terminal measures other than 5 V, inspect for the following: Open or short circuit in wiring harness Harness/pin crimp is loose or disconnected.

GND system inspection for variable resistance type 1

Confirm that terminal sensor #5 is at 0 V. If it is at 0 V, inspect the sensor. If necessary, replace the sensor. If not, inspect for the following: Open or short circuit in wiring harness Female terminal opening is loose causing an open or short circuit in wiring harness Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected.

Scheme 14

Scheme 14: Variable resistance type 2 (mass air flow (MAF) sensor and VSS)

GND system inspection for variable resistance type 2

Confirm that terminal sensor #4 is at 0 V. If it is at 0 V, inspect the sensor. If necessary, replace the sensor. If not at 0 V, inspect for the following: Open circuit in wiring harness Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected.

Input signal system inspection for variable resistance type 2

When an irregular signal is detected, measure the #1 PCM terminal voltage. If the #1 terminal voltage and the M-MDS monitor voltage are the same, proceed to the next step. If there is a difference of 0.5 V or more, inspect for the following points concerning the PCM connector: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected.
Measure the #2 sensor terminal voltage. If there is a 0.5 V or more difference between the sensor and the M-MDS voltages, inspect the wiring harness for open or short circuits. If the sensor and the M-MDS voltages are the same, inspect the following points concerning the sensor connector: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected. If there are no problems, proceed to next investigation below.

Electrical supply system inspection for variable resistance type 2

Confirm that the sensor #3 terminal is B+. If the measured voltage on the #3 terminal is B+, inspect the following points on the sensor connector. If there is no problem, inspect for the following: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) If the #3 terminal measures other than B+, inspect the following: Open or short circuit in wiring harness Harness/pin crimp is loose or disconnected.

Scheme 15

Scheme 15: Thermistor type (IAT sensor and ECT sensor)

Input signal system inspection for thermistor type

When an irregular signal is detected, measure the #1 PCM terminal voltage. If the #1 terminal voltage and the M-MDS monitor voltage are the same, proceed to the next step. If there is a difference of 0.5 V or more, inspect the following points concerning the PCM connector: Female terminal opening loose Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected.
Measure the #2 sensor terminal voltage. If there is a 0.5 V or more difference between the sensor and the M-MDS voltages, inspect the wiring harness for open or short circuits. If the sensor and the M-MDS voltages are the same, inspect the following points concerning the sensor connector: Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected. If there are no problems, proceed to next investigation below.

GND system inspection for thermistor type

Confirm that terminal sensor #3 is at 0 V. If it is at 0 V, inspect the sensor. If necessary, replace the sensor. If not, inspect for the following: Open circuit in wiring harness Female terminal opening is loose. Coupler (pin holder) damage Pin discoloration (blackness) Harness/pin crimp is loose or disconnected.

Intake Manifold Vacuum Inspection

Verify air intake hoses are installed properly.
Start the engine and run it at idle.
Disconnect the vacuum hose between the intake manifold and purge solenoid valve from the intake manifold side.
Connect a vacuum gauge to the intake manifold and measure the intake manifold vacuum. If not as specified, inspect the following: Specification (LF) ATX: More than 55 kPa {413 mmHg, 16 inHg} MTX: More than 57 kPa {428 mmHg, 17 inHg} Specification (L3) ATX: More than 57 kPa {428 mmHg, 17 inHg} MTX: More than 60 kPa {451 mmHg, 18 inHg} NOTE: Air suction can be located by engine speed change when lubricant is sprayed on the area where suction is occurring. Air suction at throttle body, intake manifold and PCV valve installation points EGR valve (stuck open) Fuel injector insulator Engine compression (See «COMPRESSION INSPECTION [LF, L3]»(ref-345205-S38965285782009102000000) .)

Engine coolant temperature compensation inspection

Connect the M-MDS to the DLC-2.
Access the following PIDs: ECT IAT RPM
Verify that the engine is cold, then start the engine.
Verify that the engine speed decreases as the engine warms up. If the engine speed does not decrease or decreases slowly, inspect the following: ECT sensor and related wiring harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [LF, L3]»(ref-345210-S19863593132009102000000) .) Electronic throttle body and related wiring harness (See «THROTTLE BODY INSPECTION [LF, L3]»(ref-345212-S26270258212009102000000) .)

Load compensation inspection

Start the engine and idle it.
Connect the M-MDS to the DLC-2.
Verify that P0506, P0507, or P0511 is not displayed. If P0506, P0507 or P0511 are displayed, perform DTC inspection. (See «DTC TABLE [LF, L3]»(ref-345244-S27941921642009102000000) .)
Access the RPM PID. NOTE: Excludes temporary idle speed drop just after the loads are turned on.
Verify that the engine speed is within the specification under each load condition. If load condition is not as specified, inspect the following: A/C switch and related wiring harness (See «CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER]»(ref-345245-S41100623352009102000000) , «CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER]»(ref-345245-S01220509002009102000000) .) Fan switch and related wiring harness (See «CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER]»(ref-345245-S41100623352009102000000) , «CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER]»(ref-345245-S01220509002009102000000) .)

Throttle position (TP) sweep inspection

Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position.
Verify that none of the following DTC are displayed: P0122, P0123, P0222, P0223, P0638, P2100(Except for California emission applicable model), P2101, P2102(Except for California emission applicable model), P2103(Except for California emission applicable model), P2106(California emission regulation applicable model), P2107, P2108, P2109(California emission regulation applicable model), P2112(California emission regulation applicable model), P2119, P2122, P2123, P2127, P2128, P2135, P2138 If any one DTC is displayed, perform DTC inspection.
Access TP_REL PID.
Verify that the PID reading is within the CTP value. (See «PCM INSPECTION [LF, L3]»(ref-345210-S28452767562009102000000) .) If the PID reading is out of range, perform the following: Remove the air duct from the throttle valve body. Verify that the throttle valve opens when the accelerator pedal is depressed. If the throttle valve opens, inspect the throttle position sensor and related wiring harness. If the throttle valve does not open, inspect the throttle actuator control motor and related wiring harness.
Gradually depress the throttle pedal and verify that the PID reading increases accordingly. If the PID reading drops momentarily, inspect the following: Throttle position sensor
Fully depress the throttle pedal and verify that the PID reading is within WOT value. (See «PCM INSPECTION [LF, L3]»(ref-345210-S28452767562009102000000) .) If the PID reading is out of range, perform the followings: Remove the air duct from throttle valve body. Verify that the throttle valve opens when throttle pedal is depressed. If the throttle valve opens, inspect the throttle position sensor and related wiring harness. If the throttle valve does not open, inspect the throttle actuator control motor and related wiring harness.

Fuel Cut Control System Inspection

Warm up engine and idle it.
Turn off the electrical loads and A/C switch.
Connect the M-MDS to the DLC-2.
Access RPM PID.
Listen for the fuel injector operation sound at all cylinders using the soundscope and monitor both PIDs while performing the following steps: Depress the accelerator pedal and increase the engine speed to 4,000 rpm. Quickly release the accelerator pedal (brake pedal is not depressed) and verify that the fuel injector operation sound stops, and starts again when the engine speed drops below 2,200 rpm. If not as specified, inspect the following: ECT sensor and related wiring harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [LF, L3]»(ref-345210-S19863593132009102000000) .) Neutral/clutch pedal position switch and related wiring harness (MTX) (See «CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [LF, L3]»(ref-345210-S25697301012009102000000) .) TR switch and related wiring harness (ATX) (See «TRANSAXLE RANGE (TR) SWITCH INSPECTION [FN4A-EL]»(ref-345215-S24381870762009102000000) , «TRANSAXLE RANGE (TR) SWITCH INSPECTION [FS5A-EL]»(ref-345217-S41672016032009102000000) .)

Fuel Pump Control System Inspection

Crank the engine and verify that fuel pump relay operation sound is heard.
If operation sound is not heard, inspect the following: Fuel pump relay (See «RELAY INSPECTION»(ref-345246-S40836865082009102000000) .) Wiring harness and connectors (Main relay - fuel pump relay - PCM terminal 1 AR (with immobilizer system), 1AQ (without immobilizer system)

Spark Test

Disconnect the fuel pump relay.
Verify that each ignition coil and connector is connected properly.
Inspect the ignition system in the following procedure. WARNING: High voltage in the ignition system can cause strong electrical shock which can result in serious injury. Avoid direct contact to the vehicle body during the following spark test.

STEP	INSPECTION		ACTION
1	Disconnect the ignition coil from the spark plugs. Remove the spark plugs. Verify that the spark plugs do not have carbon deposits. Are the spark plugs normal?	Yes	Go to the next step.
1		No	Perform no-load racing at 4,000 rpm for 2 min, 2 times to burn off the carbon deposits. Repeat Step 1.
2	Inspect the spark plugs for damage, wear, and proper plug gap. Are the spark plugs normal?	Yes	Go to the next step.
2		No	Replace spark plugs, then go to the next step.
3	Reconnect the spark plugs to the ignition coil. Ground the spark plugs to the engine. Is a strong blue spark visible at each cylinder while cranking the engine?	Yes	Ignition system is normal.
3		No	Some cylinders do not spark: Go to the next step. All cylinders do not spark: Go to Step 5.
4	Inspect the following wiring harnesses for open or short: Ignition coil No.1 terminal B-PCM terminal 2BE Ignition coil No.2 terminal B-PCM terminal 2BF Ignition coil No.3 terminal B-PCM terminal 2BG Ignition coil No.4 terminal B-PCM terminal 2BH Are the wiring harnesses normal?	Yes	Inspect and replace the ignition coil. (See IGNITION COIL INSPECTION [LF, L3] .)
4		No	Repair or replace the malfunctioning part, then go to Step.1.
5	Measure the voltage at terminal A in each ignition coils. Is the voltage B+?	Yes	Go to the next step.
5		No	Inspect power supply circuit of ignition coils.
6	Does the PCM connector or ignition coil connectors have poor connection?	Yes	Repair or replace the connector, then go to Step.1.
6		No	Go to the next step.
7	Are the following parts normal? CKP sensor and crankshaft pulley	Yes	Inspect for open or short circuit in wiring harness and connector of CKP sensor.
7		No	Repair or replace the malfunctioning part, then go to Step.1.

DIAGNOSTIC PROCEDURE

EGR Control System Inspection

Crank the engine and verify that EGR valve operation (initial operation) sound is heard. If the operation sound is not heard, connect the M-MDS to the DLC-2 and verify that the DTC P0403 is shown. Perform DTC inspection. (See «DTC TABLE [LF, L3]»(ref-345244-S27941921642009102000000) .)
Start the engine and idle it.
Warm up the engine to normal operating temperature.
Access the following PIDs: ECT, RPM, SEGRP_DSD, APP1, APP2, VSS
Idle the vehicle and verify that the SEGRP value is 0.
Put the vehicle in drive.
Depress the accelerator pedal and verify that the SEGRP_DSD value is increased. If the EGR valve increases, inspect the following: EGR valve (stuck open or close) Wiring harness and connectors (Main relay - EGR valve - PCM) If the SEGRP_DSD value does not increase, inspect the VSS, APP1, APP2, TP and ECT PIDs. (See «PCM INSPECTION [LF, L3]»(ref-345210-S28452767562009102000000) .)
Stop the vehicle and verify that the SEGRP value returns to 0.

Purge Control System Inspection

Start the engine.
Disconnect the vacuum hose between the purge solenoid valve and the charcoal canister.
Put a finger to the purge solenoid valve and verify that there is no vacuum applied when the engine is cold. If there is a vacuum, inspect the following: Wiring harness and connectors (Purge solenoid valve-PCM terminal 2AN) Purge solenoid valve
Warm up the engine to the normal operating temperature.
Stop the engine.
Connect the M-MDS to the DLC-2 and verify that the DTC P0443 is shown. Perform DTC inspection. (See «DTC TABLE [LF, L3]»(ref-345244-S27941921642009102000000) .)
Turn the ignition switch to the ON position.
Access ECT PID.
Verify that the engine coolant temperature is more than 78°C {173°F}. If the M-MDS indicates less than 78°C {173°F}, perform the ECT sensor inspection.
Set the vehicle on the dynamometer or chassis roller. WARNING: When the dynamometer or chassis roller is operating, there is a possibility that the operator may come into contact with or be caught up in the rotating parts, leading to serious injuries or death. When performing work while the dynamometer or chassis roller is operating, be careful not to come into contact with or be caught up in any of the rotating parts.
Drive vehicle at engine speed approx. 2000 rpm for 30 s or more.
Put a finger to the purge solenoid valve and verify that there is no vacuum applied while step 2 . If there is no vacuum, inspect the following: Wiring harness and connector (Main relay - purge solenoid valve - PCM terminal 2AN) Purge solenoid valve MAF, APP1, APP2, TP and LOAD PIDs If there is vacuum, inspect the following: Vacuum hose (Purge solenoid valve - charcoal canister)

A/C Cut-off Control System Inspection

Start the engine.
Turn the A/C switch and the fan switch on.
Verify that the A/C compressor magnetic clutch actuates. If it does not actuate, go to symptom troubleshooting " «NO.23 A/C DOES NOT WORK SUFFICIENTLY»(ref-345223-S16951369532009102000000) ".
Fully open the throttle valve and verify that the A/C compressor magnetic clutch does not actuate for 2-5 s. If it actuates, inspect as follows: A/C relay Open or short to GND circuit in wiring harness and connectors (Ignition switch-A/C relay-PCM terminal 1AN) A/C related parts APP1, APP2PIDS

Cooling Fan Control System Inspection

Verify that the battery voltage is more than 12.4 V. If the battery voltage is less than 12.4 V, charge the battery or connect the external power supply.
Connect the M-MDS and access ECT PID.
Turn A/C switch to off.
Verify ECT PID is less than 98°C {209°F}. If ECT PID more than 98°C {209°F}, inspect ECT sensor and related wiring harnesses.
Verify that the cooling fan does not operate with ECT PID is less than 98°C {209°F} while the ignition switch is ON. If the cooling fan operates, inspect for following parts and related wiring harnesses: ECT sensor A/C switch A/C refrigerant pressure switch (High/low pressure) A/C refrigerant pressure switch (Medium pressure) VSS A/C magnetic clutch Fan control signal circuit (between fan control module terminal B and PCM terminal 1W) If the all items are normal, replace fan control module.
Verify the cooling fan operates while the A/C switch to ON with the ignition switch at ON position. If the cooling fan does not operate, inspect for following: A/C switch A/C refrigerant pressure switch (High/low pressure) Fan control module power supply circuit Fan control module GND circuit Fan control signal circuit (between fan control module terminal B and PCM terminal 1W) If the all items are normal, replace fan control module.
Verify that the cooling fan operates with following table. COOLING FAN OPERATING REFERENCE PCM terminal 1R voltage B+ (off)* 0V (ON)* Cooling fan speed Middle speed High speed (1) A/C refrigerant pressure switch (Medium pressure) condition If the cooling fan operation is not specified, inspect for following: A/C refrigerant pressure switch (Medium pressure) If the A/C refrigerant pressure switch (Medium pressure) is normal, replace fan control module.
Turn A/C switch to off.
Start the engine and idle it.
Verify that the cooling fan operating speed increases relative to ECT PID increases. If the cooling fan speed does not increase inspect following: ECT sensor (characteristic) (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [LF, L3]»(ref-345210-S19863593132009102000000) .) Fan control signal circuit (between fan control module terminal B and PCM terminal 1W) If the all items are normal, replace fan control module.

Evaporative Emission (EVAP) System Leak Inspection

To verify that the problem has been fixed properly after repairs, the run drive cycle or EVAP system leak inspection must be performed.

EVAP system leak inspection using M-MDS

Note. EVAP system test outline

The EVAP system test, which can substituted for the run drive cycle as EVAP control system repair confirmation method, can be done while operating the M-MDS in the KOEO (Key On Engine Off) condition instead of actually driving the vehicle.

Scheme 16

Scheme 16: EVAP system test description

The EVAP system test finds gas leaks in the system using the PCM to monitor changes in the air pump load current of the EVAP system leak detection pump. This test starts after sending an on-demand test signal from the M-MDS to the PCM. The PCM controls the air pump and change-over-valve operation and also stores the load current of the air pump as follows: The PCM commands turn the air pump on and retrieve the air pump load current value (LDP_MON PID) as a reference current (LDP_REF PID). After retrieving a reference current value, the PCM commands the change-over-valve to open, then captures the air pump load current value (LDP_MON PID) as idle current (LDP_IDL PID). The EVAP system will be pressurized from this phase. The PCM continues to monitor the air pump load current value (LDP_MON PID) until the end of the test.
You can confirm whether any evaporative gas leak occurred or not by reading the test results.

Scheme 17

Scheme 17: EVAP system malfunction judgment

The PCM calculates the stored air pump load current value and send the results to the M-MDS as DTCs

DTC No.	Condition
P0442	Evaporative emission control system leak detected (small leak)
P0446	Change over valve (COV) (EVP system leak detection pump) stuck close
P0455	Evaporative emission control system leak detected (gross leak)
P0456	Evaporative emission system leak detected (very small leak)
P2401	EVAP system leak detection pump motor circuit low
P2402	EVAP system leak detection pump motor circuit high
P2404	EVAP system leak detection pump sense circuit problem
P2405	EVAP system leak detection pump sense circuit low input
P2407	EVAP system leak detection pump sense circuit intermittent

DTC REFERENCE

Evaporative system test procedure

Select the EVAP system test from the Toolbox on the M-MDS display and follow the instructions.
Verify that all of the following PIDs are within the specifications at the pre-test confirmation screen. NOTE: To successfully perform this procedure, all PIDs must be within the following specifications before proceeding to the next step. The PCM will cancel the EVAP system test if the VPWR PID value falls lower than 11.0 V during the test. Specification PID SPECIFICATIONS PID PID Range BARO 72.2 kPa {543 mmHg, 21.3 inHg} or more FLI 15-85% IAT 5-45°C{41-113°F} VPWR 11.0 V or more
Start the engine.
Drive the vehicle or let the engine idle more than 20 min.
Turn ignition switch off, then turn it to the ON position again (Key On Engine Off).
Press the tick icon to start the test.
Verify that no DTCs present after the completion of the test. If any test result is indicated with red, diagnose the problem using the following DTC troubleshooting procedure or component inspection procedure. If any DTCs are detected, diagnose the problem using the appropriate DTC troubleshooting procedure.

Scheme 18

Scheme 18: EVAP system leak inspection using leak tester

Scheme 19

Perform the following SST (EVAP System Tester 134-01049) self-test: NOTE: If the tester does not work correctly during the self-test, refer to the tester operators manual for a more detailed self-test procedure. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve. Connect the vehicle interface hose (part of the SST ) to the SELF-TEST port located on the control panel. Hand tighten the fitting. (Do not overtighten.) Turn the control valve to the TEST position. The gauge should read 331-381 mm {13- 15 in} of water. If the gauge is not reading in this range, adjust the pressure by turning the black knob on the low pressure regulator at the nitrogen bottle. Turn the control valve to the HOLD position. Verify that the gauge holds pressure and that the flow meter reads no flow. If there is no drop in pressure and no flow, the tester passes the self-test. If the gauge leaks down, refer to the tester operators manual.
Connect the SST to the vehicle. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve. Remove the fuel-filler cap from the vehicle. If the fuel-filler cap is not a MAZDA part or equivalent, replace it. Connect the receiver assembly (SST: AKS441130) to the vehicle cap test hose assembly (part of the SST ) and the fuel-filler cap from the vehicle. Connect the cap adaptor ( SST: AKS441131) to the vehicle cap test hose assembly (part of the SST ) and to the fuel-filler neck. Connect the vehicle interface hose (part of the SST ) to the center fitting of the vehicle cap test hose assembly (part of the SST ).
Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position (Engine off).
Request the PCM on-board device control (Mode 08) using the M-MDS to close the change-over valve (COV) in the EVAP system leak detection pump. NOTE: The COV is closed for 10 min unless the following any actions are done: The engine is started. The ignition switch is turned off position.
Make sure the control valve on the 134-01049 is in the HOLD position and that the valve on the cylinder of nitrogen gas is open.
Turn the control valve to the open position and let the system fill. You should note a drop in the gauge pressure along with the flow meter being pegged at maximum flow for several minutes depending on how full or empty the fuel tank is, and how long it takes to completely fill and pressurize the evaporative emissions system hoses.
If the gauge and the flow meter do not settle to a measurable level after 2-3 min, then refer to the Mazda Workshop Manual to verify that the cut or vent valve is properly closed.
Verify the pressure gauge and flow meter reading to determine if there is an evaporative emissions leak: NO EVAPORATIVE LEAK: The flow meter registers "zero flow" and the pressure gauge returns to the pre-set pressure of 356 mm {14 in} of water (H2O). EVAPORATIVE LEAK: The pressure does not return to the preset level of 356 mm {14 in} of water (H2O) when measuring the flow. See (.020 to .040 inch H2O) of the Evaporative Emissions Tester operators manual (134-01067). NOTE: Turn the control valve to the HOLD position then disconnect the SST.

Symptom Troubleshooting - Engine - (Lf, L3): Diagnosis Mazda 3 BL

SYMPTOM TROUBLESHOOTING WIRING DIAGRAM [LF, L3]

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

ENGINE SYMPTOM TROUBLESHOOTING [LF, L3]

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Diagnostic procedure

Inspection Method for Sensors

Scheme 13

Input Signal System Inspection Procedure

Input signal system inspection for variable resistance type 1

Standard power supply system inspection for variable resistance type 1

GND system inspection for variable resistance type 1

Scheme 14

GND system inspection for variable resistance type 2

Input signal system inspection for variable resistance type 2

Electrical supply system inspection for variable resistance type 2

Scheme 15

Input signal system inspection for thermistor type

GND system inspection for thermistor type

Intake Manifold Vacuum Inspection

Engine coolant temperature compensation inspection

Load compensation inspection

Throttle position (TP) sweep inspection

Fuel Cut Control System Inspection

Fuel Pump Control System Inspection

Spark Test

EGR Control System Inspection

Purge Control System Inspection

A/C Cut-off Control System Inspection

Cooling Fan Control System Inspection

Evaporative Emission (EVAP) System Leak Inspection

EVAP system leak inspection using M-MDS

Scheme 16

Scheme 17

Evaporative system test procedure

Scheme 18

Scheme 19

More articles — Symptom Troubleshooting - Engine - (Lf, L3)

Login / Signup

Enter the code

You have successfully logged in!