Symptom Troubleshooting - Engine Control System (Aj): Diagnosis

Inspection Method for Sensors

Connect the M-MDS to the DLC-2.
Turn ignition switch to ON position (Engine OFF). NOTE: If engine starts and runs, perform the following steps at 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 139

Scheme 139: Inspection Method for Actuators or Relays

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

SYMPTOM DIAGNOSTIC INDEX [AJ]

No.	TROUBLESHOOTING ITEM		DESCRIPTION	PAGE
1	Melting of main or other fuses			(See NO. 1 MELTING OF MAIN OR OTHER FUSES [AJ] ).
2	MIL illuminates		MIL is illuminated incorrectly.	(See NO. 2 MIL ILLUMINATES [AJ] ).
3	Will not crank		Starter does not work.	(See NO. 3 WILL NOT CRANK [AJ] ).
4	Hard start/long crank/erratic start/erratic crank		Starter cranks engine at normal speed but engine requires excessive cranking time before starting.	(See NO. 4 HARD START/LONG CRANK/ERRATIC START/ERRATIC CRANK [AJ] ).
5	Engine stalls	After start/at idle	Engine stops unexpectedly at idle and/or after start.	(See NO. 5 ENGINE STALLS-AFTER START/AT IDLE [AJ] ).
6	Cranks normally but will not start		Starter cranks engine at normal speed but engine will not run.	(See NO. 6 CRANKS NORMALLY BUT WILL NOT START [AJ] ).
7	Slow return to idle		Engine takes more time than normal to return to idle speed.	(See NO. 7 SLOW RETURN TO IDLE [AJ] ).
8	Engine runs rough/rolling idle		Engine speed fluctuates between specified idle speed and lower speed and engine shakes excessively.	(See NO. 8 ENGINE RUNS ROUGH/ROLLING IDLE [AJ] ).
9	Fast idle/runs on		Engine speed continues at fast idle after warm-up. Engine runs after ignition switch is turned to off.	(See NO. 9 FAST IDLE/RUNS ON [AJ] ).
10	Low idle/stalls during deceleration		Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.	(See NO. 10 LOW IDLE/STALLS DURING DECELERATION [AJ] ).
11	Engine stalls/quits	Acceleration/cruise	Engine stops unexpectedly at beginning of acceleration or during acceleration. Engine stops unexpectedly while cruising.	(See NO. 11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, SURGES [AJ] ).
	Engine runs rough	Acceleration/cruise	Engine speed fluctuates during acceleration or cruising.
	Misses	Acceleration/cruise	Engine misses during acceleration or cruising.
	Buck/jerk	Acceleration/cruise/deceleration	Vehicle bucks/jerks during acceleration, cruising, or deceleration.
	Hesitation/stumble	Acceleration	Momentary pause at beginning of acceleration, or during acceleration
	Surges	Acceleration/cruise	Momentary minor irregularity in engine output
12	Lack/loss of power	Acceleration/cruise	Performance poor under load (e.g. power down when climbing hills).	(See NO. 12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [AJ] ).
13	Knocking/pinging	Acceleration/cruise	Sound is produced when air/fuel mixture is ignited by something other than spark plug (e.g. hot spot in combustion chamber).	(See NO. 13 KNOCKING/PINGING-ACCELERATION/CRUISE [AJ] ).
14	Poor fuel economy		Fuel economy is unsatisfactory.	(See NO. 14 POOR FUEL ECONOMY [AJ] ).
15	Emissions compliance		Fails emissions test	(See NO. 15 EMISSION COMPLIANCE [AJ] ).
16	High oil consumption/leakage		Oil consumption is excessive.	(See NO. 16 HIGH OIL CONSUMPTION/LEAKAGE [AJ] ).
17	Cooling system concerns	Overheating	Engine runs at higher than normal temperature/overheats.	(See NO. 17 COOLING SYSTEM CONCERNS-OVERHEATING [AJ] ).
18	Cooling system concerns	Runs cold	Engine does not reach normal operating temperature.	(See NO. 18 COOLING SYSTEM CONCERNS-RUNS COLD [AJ] ).
19	Exhaust smoke		Blue, black, or white smoke from exhaust system	(See NO. 19 EXHAUST SMOKE [AJ] ).
20	Fuel odor (in engine compartment)		Gasoline fuel smell or visible leakage	(See NO. 20 FUEL ODOR (IN ENGINE COMPARTMENT) [AJ] ).
21	Engine noise		Engine noise from under hood	(See NO. 21 ENGINE NOISE [AJ] ).
22	Vibration concerns (engine)		Vibration from under hood or driveline	(See NO. 22 VIBRATION CONCERNS (ENGINE) [AJ] .
23	A/C does not work sufficiently		A/C compressor magnetic clutch does not engage when A/C is turned on.	(See NO. 23 A/C DOES NOT WORK SUFFICIENTLY [AJ] ).
24	A/C always on or A/C compressor runs continuously.		A/C compressor magnetic clutch does not disengage.	(See NO. 24 A/C ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY [AJ] ).
25	A/C does not cut off under wide open throttle conditions.		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 [AJ] ).
26	Exhaust sulphur smell		Rotten egg smell (sulphur) from exhaust	(See NO. 26 EXHAUST SULPHUR SMELL [AJ] ).
27	Fuel refill concerns		Fuel tank does not fill smoothly.	(See NO. 27 FUEL REFILL CONCERNS [AJ] ).
28	Fuel filling shut off issues		Fuel does not shut off properly.	(See NO. 28 FUEL FILLING SHUT OFF ISSUES [AJ] ).
29	Spark plug condition		Incorrect spark plug condition	(See NO. 29 SPARK PLUG CONDITION [AJ] ).
30	ATX concerns	Upshift/downshift/engagement	ATX concerns not related to engine performance	(See SYMPTOM TROUBLESHOOTING ITEM TABLE [AW6A-EL] ).

SYMPTOM DIAGNOSTIC

Scheme 140

Scheme 140: SYMPTOM QUICK DIAGNOSIS CHART [AJ]

Scheme 141

Scheme 142

Scheme 143

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2. Turn ignition switch to ON position. Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
1		No	No DTC is displayed: Inspect for short to GND circuit between instrument cluster and PCM terminal 2AE. Inspect instrument cluster operation (See INSTRUMENT CLUSTER INSPECTION ).
2	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2. Do following conditions appear? Engine is not completely started. DTC B1681 is displayed.	Yes	Both conditions appear: Go to Step 4.
1		No	Either or other condition appears: Go to the next step.
2	Is coil connector securely connected to coil?	Yes	Go to the next step.
2	Is coil connector securely connected to coil?	No	Connect coil connector securely. Return to step 1.
3	Does security light illuminate?	Yes	Go to the next step.
3	Does security light illuminate?	No	Inspect instrument cluster and wiring harness. (See INSTRUMENT CLUSTER INSPECTION ).
4	Connect M-MDS to DLC-2 and retrieve DTC. DTC B1213, B1342, B1600, B1601, B1602, B1681, B2103, B2431	Yes	Go to appropriate DTC test.
4		No	Go to the next step.
5	Is there continuity between PCM GND terminals 2H, 2L, 2D, 2BH, 2AZ and GND?	Yes	Go to the next step.
5		No	Repair or replace wiring harness.
6	Measure voltage between PCM GND terminals 2H, 2L, 2D, 2BH, 2AZ and coil terminals C Is voltage below 1.0 V?	Yes	Go to the next step.
6		No	Repair or replace wiring harness.
7	Turn ignition switch to ON position. Measure voltage PCM terminal 2AP and 1A. Is voltage B+?	Yes	Go to the next step.
7		No	Repair or replace wiring harness.
8	Disconnect coil connector. Turn ignition switch to ON position. Is there battery voltage at coil connector terminal D?	Yes	Go to the next step.
8		No	Repair or replace wiring harness between coil connector terminal D and fuse panel.
9	Inspect for following wiring harnesses and connectors: Between coil terminal A and PCM terminal 1J Between coil terminal B and PCM terminal 1I Is there any malfunction?	Yes	Repair or replace wiring harness.
9		No	Go to the next step.
10	Is there continuity between PCM terminal 1AD and starter relay with clutch pedal depressed (MTX), P or N position (ATX)?	Yes	Go to the next step.
10		No	Repair or replace wiring harness. For ATX inspect starter cut relay and related wiring harness
11	Inspect the following Battery connection Battery Condition (See BATTERY INSPECTION .) Fuses (See NO. 1 MELTING OF MAIN OR OTHER FUSES [AJ] .) Transmission in Park or Neutral (ATX) Are all items normal?	Yes	Go to the next step.
11		No	Service as necessary. Repeat Step 11.
12	Is clicking sound heard from starter when ignition switch is turned to START position?	Yes	Go to step 17.
12		No	ATX: Go to the next step. MTX: Go to step 14.
13	Connect the M-MDS to the DLC-2. Turn 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 15
13		No	Inspect TR switch is adjusted properly, inspect for open or short circuit between TR switch and TCM. Repair or replace components as required. Then repeat step 12.
14	INSPECT STARTER INTERLOCK SWITCH Inspect the starter interlock switch Is the starter interlock switch normal?	Yes	Go to the next step.
14		No	Inspect starter interlock switch and related wiring harnesses. Repair or replace components as required. Then repeat step 12.
15	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.
15		No	Repair or replace components as required. Then repeat Step 12.
16	Inspect ignition switch and related harnesses. (See IGNITION SWITCH INSPECTION .) Are they normal?	Yes	Go to the next step.
16		No	Repair or replace components as required Then repeat step 12.
17	Inspect the following harnesses. Between starter relay and Battery Between starter relay and Starter Are they normal?	Yes	Go to the next step.
17		No	Repair or replace as required, then go to next step.
18	Inspect starting system. (See STARTER INSPECTION [L3, AJ] ). (See STARTER INTERLOCK SWITCH INSPECTION (MTX) ). Is starting system normal?	Yes	Go to the next step.
18		No	Repair or replace components as required.
19	Inspect for seized/hydro locked engine or flywheel. Is ENGINE seized or hydro locked?	Yes	Repair or replace components as required.
19		No	Go to the next step.
20	Connect M-MDS to DLC-2. Turn ignition switch to ON position. Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriated DTC inspection. (See DTC TABLE .) Communication error message is displayed: Inspect for following Open circuit between main relay terminal C and PCM terminal 2AP or 1A Open main relay GND circuit Main relay is stuck open. Open or poor GND circuit (PCM terminal 2H, 2L, 2D, 2BH, 2AZ) Poor connection of vehicle body GND
20		No	No DTC displayed: Go to the next step.
21	Retrieve any KOEO DTCs using M-MDS. ARe there any DTCs displayed during KOEO inspection?	Yes	DTC displayed: Go to the appropriate DTC inspection. (See DTC TABLE .)
21		No	No DTC displayed: Go to the next step.
22	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Inspect for the following: Vacuum leakage Proper fuel quality (e.g. proper octane, contamination, winter/summer blend) Loose bands on intake-air system Cracks on intake-air system parts Air cleaner restriction Are all items normal?	Yes	Go to the next step.
1		No	Service as necessary. Repeat Step 1.
2	Connect M-MDS to DLC-2. Turn ignition switch to ON position. Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
2		No	No DTC is displayed: Go to the next step.
3	Is engine overheating?	Yes	Go to flowchart " NO. 17 COOLING SYSTEM CONCERNS-OVERHEATING ".
3	Is engine overheating?	No	Go to the next step.
4	Inspect ignition coil related harnesses condition (intermittent open or short circuit) for all cylinders. Are all harnesses condition normal?	Yes	Go to the next step.
4		No	Repair suspected wiring harness.
5	Inspect 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 for clogged fuel injector.
5		No	Install spark plugs on original cylinders. Go to the next step.
6	Visually inspect CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
6		No	Replace malfunctioning part.
7	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
7	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
8	Install fuel pressure gauge between pulsation damper and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. (See AFTER REPAIR PROCEDURE [L3, AJ] ). Turn ignition switch to ON position (Engine OFF). Inspect fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct?	Yes	Go to the next step.
8		No	Zero or low: Inspect fuel pump relay and fuel pump related circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
9	Attempt to start engine at part throttle. Does engine run smoothly at part throttle?	Yes	Inspect electronic throttle control system operation.
9		No	Go to the next step.
10	Is fuel line pressure held after ignition switch is turned to OFF position?	Yes	Go to the next step.
10		No	Inspect fuel injector. (See FUEL INJECTOR INSPECTION [AJ] ). If fuel injector is normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
11	Disconnect vacuum hose from purge solenoid valve and plug opening end of vacuum hose. Attempt to start engine. Is starting condition improved?	Yes	Inspect if purge solenoid valve sticks open. (See PURGE SOLENOID VALVE INSPECTION [L3, AJ] ).
11		No	Go to the next step.
12	Inspect MAF sensor for contamination. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [AJ] ). Is there any contamination?	Yes	Replace MAF/IAT sensor.
12		No	Go to the next step.
13	Inspect for restriction in the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
13		No	Go to the next step.
14	Inspect engine condition while tapping EGR valve housing. Does engine condition improve?	Yes	Replace EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [AJ] ).
14		No	Go to the next step.
15	Inspect starting system. (See STARTER INSPECTION [L3, AJ] ). (See STARTER INTERLOCK SWITCH INSPECTION (MTX) ). Is starting system normal?	Yes	Inspect for loose connectors or poor terminal contact. If normal, remove EGR valve and visually inspect for mechanically stuck EGR valve. (See EGR VALVE INSPECTION [AJ] ).
15		No	Repair or replace components as required.
16	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2. Do the following conditions appear? Engine is not completely started. DTC B1681 is displayed.	Yes	Both conditions appear: Go to Step 3.
1		No	Either or other condition appear: Go to the next step.
2	Does engine stall after approx. 2 s from when engine is started?	Yes	Go to the next step.
2		No	Immobilizer system is normal. Go to Step 10.
3	Is coil connector securely connected to coil?	Yes	Go to the next step.
3	Is coil connector securely connected to coil?	No	Connect coil connector securely. Return to Step 2.
4	Does security light illuminate?	Yes	Go to the next step.
4	Does security light illuminate?	No	Inspect instrument cluster and wiring harness.
5	Connect M-MDS to DLC-2 and retrieve DTC. Are the following DTCs displayed? DTC B1213, B1342, B1600, B1601, B1602, B1681, B2103, B2431	Yes	Go to appropriate DTC test.
5		No	Go to the next step.
6	Is there continuity between PCM GND terminals 2H, 2L, 2D, 2BH, 2AZ and GND?	Yes	Go to the next step.
6		No	Repair or replace wiring harness.
7	Measure voltage between PCM GND terminals 2H, 2L, 2D, 2BH, 2AZ and coil terminal C. Is voltage below 1.0 V?	Yes	Go to the next step.
7		No	Repair or replace wiring harness.
8	Turn ignition switch to ON position. Measure voltage PCM terminal 1B and 1A. Is voltage B+?	Yes	Go to the next step.
8		No	Repair or replace wiring harness.
9	Disconnect coil connector. Turn ignition switch to ON position (Engine OFF). Is there battery voltage at coil connector terminal D?	Yes	Inspect for following: Open or short circuit between coil terminal A and PCM terminal 1J Open or short circuit between coil terminal B and PCM terminal 1I
9		No	Repair or replace wiring harness between coil connector terminal D and fuse panel.
10	Verify 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.
10		No	Service as necessary. Repeat Step 10.
11	Turn ignition switch to ON position (Engine OFF). Disconnect throttle body connector. Measure voltage at throttle body VREF terminal with ignition switch at ON position. Is voltage 4.5-5.5 V?	Yes	Go to the next step.
11		No	Inspect and repair open or short circuit between PCM terminal 1BD and throttle body VREF terminal.
12	Turn ignition switch to OFF position. Disconnect APP sensor connector. Measure voltage at APP sensor VREF terminal with ignition switch at ON position. Is voltage 4.5-5.5 V?	Yes	Go to the next step.
12		No	Repair or replace open or short circuit for the following: PCM terminal 1AR and APP sensor terminal D PCM terminal 1AV and APP sensor terminal A
13	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test. Communication error message is displayed: Inspect for following: Open circuit between main relay terminal C and PCM terminal 1B or 1A Open main relay GND circuit Main relay is stuck open. Open or poor GND circuit (PCM terminal 2H, 2L, 2D, 2BH, 2AZ) Poor connection of vehicle body GND
13		No	No DTC is displayed: Go to the next step.
14	Attempt to start engine at part throttle. Does engine run smoothly at part throttle?	Yes	Inspect electronic throttle control system operation.
14		No	Go to the next step.
15	Connect M-MDS to DLC-2. Access RPM PID. Is RPM PID indicating engine speed during engine cranking?	Yes	Go to the next step.
15		No	Inspect for the following: Open or short circuit in CKP sensor Open or short circuit between CKP sensor and PCM terminal 2Z or 2Y Open or short circuit in CKP sensor harnesses If CKP sensor and harness are normal, go to the next step.
16	Visually inspect CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
16		No	Replace malfunctioning part.
17	Inspect ignition coil related harness condition (intermittent open or short) for all cylinders. Are all harnesses condition normal?	Yes	Go to the next step.
17		No	Repair suspected wiring harness.
18	Perform spark test. (See SPARK TEST ). Is strong blue spark visible at each cylinder?	Yes	Go to the next step. If symptom occurs with A/C on, go to Step 24.
18		No	Repair or replace malfunctioning part according to spark test results.
19	Inspect 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 for clogged fuel injector.
19		No	Install spark plugs on original cylinders. Go to the next step.
20	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
20	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
21	Inspect for restriction in the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
21		No	Go to the next step.
22	Install fuel pressure gauge between fuel filter and fuel distributor. Short the check connector terminal F/P to body GND using a jumper wire. (See AFTER REPAIR PROCEDURE [L3, AJ] ). Turn ignition switch to ON position (Engine OFF). Inspect fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct?	Yes	Go to the next step.
22		No	Zero or low: Inspect fuel pump relay and fuel pump related circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
23	Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service if necessary. Turn OFF fuel pump using FP PID in output state control of data logger function. Does fuel line pressure hold after ignition switch is turned to OFF position?	Yes	Go to the next step.
23		No	Inspect fuel injector. (See FUEL INJECTOR INSPECTION [AJ] ). If fuel injector is normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
24	NOTE: The following test is for stall concerns with 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 pressure. Are pressures within specifications? (See REFRIGERANT PRESSURE CHECK [L3, AJ] ).	Yes	Go to the next step.
24		No	If A/C is always on, go to symptom troubleshooting " NO. 24 A/C ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY ". For other symptoms, inspect following: Refrigerant charging amount Condenser fan operation
25	Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid side. Plug opening end of vacuum hose. Start engine. Is engine stall now eliminated?	Yes	Inspect if purge solenoid valve is stuck open. Inspect EVAP control system.
25		No	Go to the next step.
26	Is air leakage felt or heard at intake-air system components while racing engine to higher speed?	Yes	Repair or replace.
26		No	Go to the next step.
27	Inspect engine condition while tapping EGR valve housing. Does engine condition improve?	Yes	Replace EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [AJ] ).
27		No	Go to the next step.
28	Perform variable valve timing control system operation inspection. (See VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION INSPECTION ). Does variable valve timing control system work properly?	Yes	Go to the next step.
28		No	Repair or replace malfunctioning part according to variable valve timing system operation inspection results.
29	Is engine compression correct? (See COMPRESSION INSPECTION [AJ] ).	Yes	Inspect valve timing.
29		No	Inspect for cause.
30	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

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

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	NOTE: The following test should be performed on vehicles with immobilizer system. Go to Step 12 for vehicles without immobilizer system. Connect M-MDS to DLC-2. Do the following conditions appear? Engine is not completely started. DTC B1681 is displayed.	Yes	Both conditions appear: Go to Step 3.
1		No	Either or other condition appear: Go to the next step.
2	Does engine stall after approx. 2 s from when engine is started?	Yes	Go to the next step.
2		No	Immobilizer system is normal. Go to Step 10.
3	Is coil connector securely connected to coil?	Yes	Go to the next step.
3	Is coil connector securely connected to coil?	No	Connect coil connector securely. Return to Step 2.
4	Does security light illuminate?	Yes	Go to the next step.
4	Does security light illuminate?	No	Inspect instrument cluster and wiring harness.
5	Connect M-MDS to DLC-2 and retrieve DTC. Are the following DTCs displayed? DTC B1602, B1603, B1604, B1621, B1622, B1624	Yes	Go to appropriate DTC test.
5		No	Go to the next step.
6	Is there continuity between PCM GND terminals 2H, 2L, 2D, 2BH, 2AZ and GND?	Yes	Go to the next step.
6		No	Repair or replace wiring harness.
7	Measure voltage between PCM GND terminals 2H, 2L, 2D, 2BH, 2AZ and coil terminal C. Is voltage below 1.0 V?	Yes	Go to the next step.
7		No	Repair or replace wiring harness.
8	Turn ignition switch to ON position. Measure voltage PCM terminal 1B and 1 A. Is voltage B+?	Yes	Go to the next step.
8		No	Repair or replace wiring harness.
9	Disconnect coil connector. Turn ignition switch to ON position (Engine OFF). Is there battery voltage at coil connector terminal D?	Yes	Inspect for following: Open or short circuit between coil terminal A and PCM terminal 1J Open or short circuit between coil terminal B and PCM terminal 1I
9		No	Repair or replace wiring harness between coil connector terminal D and fuse panel.
10	Verify following: Vacuum connection External fuel shut off or accessory (kill switch, alarm etc). Fuel quality: 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 Are all items normal?	Yes	Go to the next step.
10		No	Service as necessary. Repeat Step 10.
11	Connect M-MDS to DLC-2. Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test. Communication error message is displayed: Inspect for the following: Open circuit between main relay terminal C and PCM terminal 1B or 1A Open main relay GND circuit Main relay is stuck open. Open or poor GND circuit (PCM terminal 2H, 2L, 2D, 2BH, 2AZ) Poor connection of vehicle body GND
11		No	No DTC is displayed: Go to the next step.
12	Turn ignition switch to ON position (Engine OFF). Disconnect throttle body connector. Measure voltage at throttle body VREF terminal with ignition switch at ON position. Is voltage 4.5-5.5 V?	Yes	Go to the next step.
12		No	Inspect and repair open or short circuit between PCM terminal 2AR and throttle body VREF terminal.
13	Turn ignition switch to OFF position. Disconnect APP sensor connector. Measure voltage at APP sensor VREF terminal with ignition switch at ON position. Is voltage 4.5-5.5 V?	Yes	Go to the next step.
13		No	Repair or replace open or short circuit for the following: PCM terminal 1AR and APP sensor terminal D PCM terminal 1AV and APP sensor terminal A
14	Will engine start and run smoothly at part throttle?	Yes	Inspect electronic throttle control system operation (See ELECTRONIC THROTTLE CONTROL INSPECTION ).
14	Will engine start and run smoothly at part throttle?	No	Go to the next step.
15	Connect M-MDS to DLC-2. Access RPM PID. Is RPM PID indicating engine speed when cranking engine?	Yes	Go to the next step.
15		No	Inspect for the following: Open or short circuit in CKP sensor Open or short circuit between CKP sensor and PCM terminal 2Z or 2Y Open or short circuit in CKP sensor harnesses If CKP sensor and harness are normal, go to the next step.
16	Visually inspect CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
16		No	Replace malfunctioning part.
17	Inspect ignition coil related harnesses condition (intermittent open or short) for all cylinders. Are all harnesses condition normal?	Yes	Go to the next step.
17		No	Repair suspected wiring harness.
18	Perform spark test. (See SPARK TEST ). Is strong blue spark visible at each cylinder?	Yes	Go to the next step.
18		No	Repair or replace malfunctioning part according to malfunction results.
19	Inspect 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 for clogged fuel injector.
19		No	Install spark plugs on original cylinders. Go to the next step.
20	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
20	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
21	Inspect for restriction in the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
21		No	Go to the next step.
22	Install fuel pressure gauge between pulsation damper and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. (See AFTER REPAIR PROCEDURE [L3, AJ] ). Turn ignition switch to ON (Engine OFF). Is fuel line pressure correct when ignition switch is cycled ON/OFF five times? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
22		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
23	Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service as necessary. Is fuel line pressure held after ignition switch is turned to OFF position?	Yes	Go to the next step.
23		No	Inspect fuel injector. (See FUEL INJECTOR INSPECTION [AJ] ). If fuel injector is normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
24	Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Attempt to start engine. Is starting condition improved?	Yes	Inspect if purge solenoid valve is stuck open mechanically. Inspect EVAP control system.
24		No	Go to the next step.
25	Is air leakage felt or heard at intake-air system components while racing engine to higher speed?	Yes	Repair or replace.
25		No	Go to the next step.
26	Inspect engine condition while tapping EGR valve housing. Does engine condition improve?	Yes	Replace EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [AJ] ).
26		No	Go to the next step.
27	Perform variable valve timing control system operation inspection. (See VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION INSPECTION ). Does variable valve timing control system work properly?	Yes	Go to the next step.
27		No	Repair or replace malfunctioning part according to variable valve timing control system operation inspection results.
28	Is engine compression correct? (See COMPRESSION INSPECTION [AJ] ).	Yes	Inspect valve timing.
28		No	Inspect for causes.
29	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

NOTE
The following test should be performed on vehicles with immobilizer system. Go to Step 12 for vehicles without immobilizer system.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
1		No	No DTC is displayed: Go to the next step.
2	Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [L3, AJ] ). (See THERMOSTAT INSPECTION [L3, AJ] ). Is thermostat normal?	Yes	ECT and thermostat are normal. Go to the next step.
2		No	Access ECT PID. 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 contaminations?	Yes	Inspect for air leakage from intake-air system components while racing engine to higher speed.
3	Is throttle body free of contaminations?	No	Clean or replace throttle body.
4	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Verify the following: External fuel shut off or accessory (kill switch, alarm etc). Fuel quality: 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 Are all items normal?	Yes	Go to the next step.
1		No	Service as necessary. Repeat Step 1.
2	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
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	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 run it at idle. Turn A/C switch on. Measure low side and high side pressures. Are reading pressures within specifications? (See REFRIGERANT PRESSURE CHECK [L3, AJ] ).	Yes	Go to the next step.
4		No	If A/C is always on, go to symptom troubleshooting " NO. 24 A/C ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY ". For other symptoms, inspect the following: Refrigerant charging amount Condenser fan operation
5	NOTE: The following test is for engine running rough with P/S on. If other symptoms exist, go to the next step. Start engine and run it at idle Measure voltage at PSP switch terminal A. Is voltage normal?	Yes	Go to the next step.
5		No	Inspect PSP switch operation and wiring harness between PSP switch terminal A and PCM terminal 2T.
6	Visually inspect CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
6		No	Replace malfunctioning part.
7	Inspect ignition coil related harnesses condition (intermittent open or short circuit) for all cylinders. Are all harnesses condition normal?	Yes	Go to the next step.
7		No	Repair suspected wiring harness.
8	Inspect 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 for clogged fuel injector.
8		No	Install spark plugs on original cylinders. Go to the next step.
9	Perform electronic throttle control system operation inspection. (See ELECTRONIC THROTTLE CONTROL INSPECTION ). Does electronic throttle control system work properly?	Yes	Go to the next step.
9		No	Repair or replace malfunctioning part according to electronic throttle control system operation inspection results.
10	Install fuel pressure gauge between pulsation damper and fuel distributor. Start engine and run it at idle. Measure fuel line pressure at idle. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct at idle?	Yes	Go to the next step.
10		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
11	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 to OFF position?	Yes	Go to the next step.
11		No	Inspect fuel injector. (See FUEL INJECTOR INSPECTION [AJ] ). If fuel injector is normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
12	Connect M-MDS to DLC-2. Start the engine and run it at idle. Access LONGFT1 and LONGFT2 PID. Measure LONGFT1 and LONGFT2 PID at idle. Is PID value within -15% - +15%?	Yes	Go to the next step.
12		No	LONGFT1 and LONGFT2 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 normal, go to the next step.
13	Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Start engine. Does engine condition improve?	Yes	Inspect if purge solenoid valve sticks open mechanically. Inspect EVAP control system.
13		No	Go to the next step.
14	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
14	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve. (See EGR VALVE REMOVAL/INSTALLATION [AJ] ).
15	Inspect for restriction in the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
15		No	Go to the next step.
16	Visually inspect CMP sensor and tooth of camshaft pulley. Are CMP sensor and tooth of camshaft pulley normal?	Yes	Go to the next step.
16		No	Replace malfunctioning part.
17	Inspect engine condition while tapping EGR valve housing. Does engine condition improve?	Yes	Replace EGR valve.
17		No	Go to the next step.
18	Perform variable valve timing control system inspection. (See VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION INSPECTION ). Does variable valve timing control system work properly?	Yes	Go to the next step.
18		No	Repair or replace malfunctioning part according to variable valve timing control system inspection results.
19	Is engine compression correct? (See COMPRESSION INSPECTION [AJ] ).	Yes	Inspect valve timing.
19		No	Inspect for causes.
20	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

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.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2. Access ECT PID. Start and warm-up engine to normal operating temperature. Is ECT PID reading 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 M-MDSs DLC-2. Retrieve any DTC's. Are there, any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
2		No	No DTC is displayed: Go to the next step.
3	Measure voltage at PCM terminal 1AN, 1AH, 1 AB (MTX), 2X (MTX) and 2T. Are voltage normal?	Yes	Go to Step 5.(MTX) Go to the next step.(ATX)
3		No	If PCM terminal 1AN voltage is not as specified: Inspect A/C switch, refrigerant pressure switch and fan switch. If PCM terminal 1AH voltage is not as specified: Inspect refrigerant pressure switch (middle pressure). If PCM terminal 1AB voltage is not as specified: Inspect clutch switch. If PCM terminal 2X voltage is not as specified: Inspect neutral switch. If PCM terminal 2T voltage is not as specified: Inspect PSP switch.
4	Inspect indication of selector lever position at instrument cluster. Does indicator lamp indicate properly selector lever position?	Yes	Go to the next step.
4		No	Perform N position learning. (See NEUTRAL POSITION LEARNING ). If problem remains replace TR switch. (See TCM REMOVAL/INSTALLATION [AW6A-EL] ).
5	Is there air leakage felt or heard at intake-air system components while racing engine to higher speed?	Yes	Repair or replace parts as necessary.
5		No	Inspect following: Electronic throttle control system operation Accelerator position sensor adjustment
6	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Does engine idle rough?	Yes	Go to symptom troubleshooting " NO. 8 ENGINE RUNS ROUGH/ROLLING IDLE ".
1	Does engine idle rough?	No	Go to the next step.
2	Turn off A/C switch and fan switch. Does A/C magnetic clutch engage?	Yes	Go to symptom troubleshooting " NO. 24 A/C ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY "?
2		No	Go to the next step.
3	Verify following: Proper routing 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 as necessary. Repeat Step 3.
4	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTC. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
4		No	No DTC is displayed: Go to the next step.
5	Perform electronic throttle control system operation inspection. (See ELECTRONIC THROTTLE CONTROL INSPECTION ). Does electronic controlled throttle work properly?	Yes	Go to the next step.
5		No	Repair or replace malfunctioning part according to electronic throttle control system operation inspection results.
6	Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Drive vehicle. Does engine condition improve?	Yes	Inspect EVAP control system.
6		No	Go to the next step.
7	Connect M-MDS to DLC-2. Access APP1, APP2, TP REL, MAF and VSS PIDs. Monitor each PID while driving vehicle. (See PCM INSPECTION [AJ] ). Are PIDs normal?	Yes	Intermittent concern exists. (See INTERMITTENT CONCERN TROUBLESHOOTING [AJ] ).
7		No	APP1 or APP2 PIDs: Inspect APP sensor. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [AJ] ). TP_REL PID: Inspect TP sensor. (See THROTTLE POSITION (TP) SENSOR INSPECTION [AJ] ). MAF PID: Inspect MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [AJ] ). VSS PID: Inspect VSS. (See VEHICLE SPEED SENSOR INSPECTION (WITHOUT ABS) [A65M-R] ).
8	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Verify 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.
1		No	Service as necessary. Repeat Step 1.
2	Connect M-MDS DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
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 M-MDS to DLC-2. Access APP1, APP2, RPM, MAF, TP REL and VSS PIDs. Drive vehicle while monitoring PIDs. Are PIDs within specification? (See PCM INSPECTION [AJ] ).	Yes	Go to the next step.
4		No	APP1, APP2, PIDs: Inspect if output signal APP sensor changes smoothly. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [AJ] ). RPM PID: Inspect CKP sensor and related harness for vibration or intermittent open/short circuit, or both. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [AJ] ). MAF PID: Inspect for intermittent open circuit between MAF sensor and related wire harness. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [AJ] ). TP_REL PID: Inspect if output signal from TP sensor changes smoothly. (See THROTTLE POSITION (TP) SENSOR INSPECTION [AJ] ). VSS PID: Inspect for intermittent open circuit between VSS and related wire harness. (See VEHICLE SPEED SENSOR INSPECTION (WITHOUT ABS) [A65M-R] ).
5	Visually inspect 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 malfunctioning part.
6	Inspect 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 for clogged fuel injector.
6		No	Install spark plugs on original cylinders. Go to the next step.
7	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
7	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
8	Perform electronic throttle control system operation inspection. (See ELECTRONIC THROTTLE CONTROL INSPECTION ). Does electronic controlled throttle work properly?	Yes	Go to the next step.
8		No	Repair or replace malfunctioning part according to electronic throttle control system operation inspection results.
9	Inspect for restriction in the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
9		No	Go to the next step.
10	Install fuel pressure gauge between pulsation damper and fuel distributor. Short the check connector terminal F/P to body GND using a jumper wire. (See AFTER REPAIR PROCEDURE [L3, AJ] ). Turn ignition switch to ON position (Engine OFF). Inspect fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct with ignition switch at ON position?	Yes	Go to the next step.
10		No	Zero or low: Inspect fuel pump relay and fuel pump. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
11	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 to OFF position? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
11		No	Inspect fuel injector. (See FUEL INJECTOR INSPECTION [AJ] ). If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
12	NOTE: The following test is for engine stall with 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 A/C on and measure low side and high side pressures. Are pressures within specifications? (See REFRIGERANT PRESSURE CHECK [L3, AJ] ).	Yes	Go to the next step.
12		No	If A/C is always on, go to symptom troubleshooting " NO. 24 A/C ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY ". For other symptoms, inspect following: Refrigerant charging amount Condenser fan operation
13	NOTE: Following test is performed for symptom with cruise control on. If other symptom exists, 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 malfunctioning part.
14	Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Drive vehicle. Does engine condition improve?	Yes	Inspect if purge solenoid valve is stuck open mechanically. Inspect EVAP control system.
14		No	Go to the next step.
15	Visually inspect CMP sensor and projections of camshaft pulley. Are CMP sensor and projections of camshaft pulley normal?	Yes	Go to the next step.
15		No	Replace malfunctioning parts.
16	Inspect EGR system. Is EGR system normal?	Yes	Go to the next step.
16	Inspect EGR system. Is EGR system normal?	No	Replace malfunctioning parts.
17	Is engine compression correct? (See COMPRESSION INSPECTION [AJ] ).	Yes	Inspect following: Valve timing Internal transaxle part
17		No	Inspect for cause.
18	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

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

NOTE
Following test is performed for symptom with cruise control on. If other symptom exists, go to the next step.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		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: EGR valve Fuel quality: proper octane, contamination, winter/summer blend Are all items normal?	Yes	Go to the next step.
1		No	Service as necessary. Repeat Step 1.
2	Connect M-MDS to DLC-2. Tun ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?.	Yes	DTC is displayed: Go to appropriate DTC test.
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 M-MDS to DLC-2. Access APP1, APP2, RPM, MAF, TP REL and VSS PIDs. Drive vehicle with monitoring PIDs. Are PIDs within specification? (See PCM INSPECTION [AJ] ).	Yes	Go to the next step.
4		No	APP1, APP2, PIDs: Inspect if output signal from APP sensor changes smoothly. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [AJ] ). RPM PID: Inspect CKP sensor and related harness for vibration or intermittent open/short circuit, or both. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [AJ] ). MAF PID: Inspect for intermittent open circuit between MAF sensor and related wire harness. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [AJ] ). TP_REL PID: Inspect if output signal from TP sensor changes smoothly. (See THROTTLE POSITION (TP) SENSOR INSPECTION [AJ] ). VSS PID: Inspect for intermittent open circuit between VSS and related wire harness. (See VEHICLE SPEED SENSOR INSPECTION (WITHOUT ABS) [A65M-R] ).
5	Visually inspect 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 malfunctioning part.
6	Inspect 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. Inspect ignition system for suspect cylinder. Spark plug is grayish white: Inspect for clogged fuel injector.
6		No	Install spark plugs on original cylinders. Go to the next step.
7	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
7	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
8	Perform electronic throttle control system operation inspection. (See ELECTRONIC THROTTLE CONTROL INSPECTION ). Does electronic controlled throttle work properly?	Yes	Go to the next step.
8		No	Repair or replace malfunctioning part according to electronic throttle control system operation inspection results.
9	Inspect for restriction In the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
9		No	Go to the next step.
10	Install fuel pressure gauge between pulsation damper and fuel distributor. Short the check connector terminal F/P to body GND using a jumper wire. (See AFTER REPAIR PROCEDURE [L3, AJ] ). Turn ignition switch to ON position (Engine OFF). Inspect fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct with ignition switch at ON position?	Yes	Go to the next step.
10		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. Inspect normal; replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
11	NOTE: The following test is for engine stall with A/C on. If other symptom exists, go to the next step. Connect pressure gauge to A/C low and high side pressure lines. Turn A/C on and measure low side and high side pressures. Are pressures within specifications? (See REFRIGERANT PRESSURE CHECK [L3, AJ] ).	Yes	Go to the next step.
11		No	If A/C is always on, go to symptom troubleshooting " NO. 24 A/C ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY ". For other symptoms, inspect following: Refrigerant charging amount Condenser fan operation
12	Inspect A/C cut-off operation. Does A/C cut-off work properly?	Yes	Go to the next step.
12		No	Inspect A/C cut-off system components.
13	Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. Plug opened end of vacuum hose. Drive vehicle. Does engine condition improve?	Yes	Inspect if purge solenoid valve is stuck open mechanically. Inspect EVAP control system.
13		No	Go to the next step.
14	Visually inspect CMP sensor and projections of camshaft pulley. Are CMP sensor and projections of camshaft pulley normal?	Yes	Go to the next step.
14		No	Replace malfunctioning part.
15	Inspect EGR system. Is EGR system normal?	Yes	Go to the next step.
15	Inspect EGR system. Is EGR system normal?	No	Replace malfunctioning part.
16	Perform Variable Valve Timing Control System Inspection. (See VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION INSPECTION ). Does variable valve timing control system work properly?	Yes	Go to the next step.
16		No	Repair or replace malfunctioning part according to Variable Valve Timing Control System Inspection results.
17	Is engine compression correct? (See COMPRESSION INSPECTION [AJ] ).	Yes	Inspect following: Valve timing Internal transaxle components (ATX) Clutch (MTX) Brake system for dragging
17		No	Inspect for cause.
18	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

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

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to 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 cooling system for cause of overheating.
2	Access IAT, MAF PIDs. Monitor each PID. Are PIDs normal?	Yes	Go to the next step.
2	Access IAT, MAF PIDs. Monitor each PID. Are PIDs normal?	No	IAT PID: Inspect IAT sensor. (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [AJ] ). MAF PID: Inspect MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [AJ] ).
3	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
3		No	No DTC is displayed: Go to the next step.
4	Is engine compression correct? (See COMPRESSION INSPECTION [AJ] ).	Yes	Go to the next step.
4		No	Inspect for cause.
5	Install fuel pressure gauge between pulsation damper and fuel distributor. Start engine and run it at idle. Measure fuel line pressure at idle. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct at idle?	Yes	Go to the next step.
5		No	Zero or low: Inspect fuel pump relay fuel pump circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
6	Inspect KS. (See KNOCK SENSOR (KS) INSPECTION [AJ] ). Is KS normal?	Yes	Inspect ignition timing. (See ENGINE TUNE-UP [AJ] ).
6		No	Replace KS. (See KNOCK SENSOR (KS) REMOVAL/INSTALLATION [AJ] ).
7	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Inspect following: Air cleaner element for contamination ATF level (ATX) Fuel quality Coolant level Clutch slippage (MTX) Are all items normal?	Yes	Go to the next step.
1		No	Service as necessary. Repeat Step 1.
2	Connect M-MDS to DLC-2. Tun ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
2		No	No DTC is displayed: Go to the next step.
3	Access ECT PID. Drive vehicle while monitoring PID. (See PCM INSPECTION [AJ] ). Is PID within specification?	Yes	Go to the next step.
3		No	Inspect for coolant leakage. Inspect cooling fan operations or thermostat operations.
4	Perform spark test. (See SPARK TEST ). Is strong blue spark visible at each cylinder?	Yes	Inspect for following: Spark plugs malfunction CMP sensor is installed improperly. Trigger wheel damage on camshaft Open or short circuit on CMP sensor Open or short circuit between CMP sensor and PCM terminal 2AA, 2AB, 2AD or 2AE. Repair or replace malfunctioning part. If normal, go to the next step.
4		No	Repair or replace malfunctioning part according to spark test results.
5	Install fuel pressure gauge between fuel filter and fuel distributor. Start engine and run it at idle. Measure fuel line pressure at idle. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct at idle?	Yes	Go to the next step.
5		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
6	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
6	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
7	Inspect for restriction in the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
7		No	Go to the next step.
8	Is brake system functioning properly?	Yes	Go to the next step.
8	Is brake system functioning properly?	No	Inspect for cause.
9	Inspect MAF sensor for contamination. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [AJ] ). Is there any contamination?	Yes	Replace MAF/IAT sensor.
9		No	Go to the next step.
10	Perform variable valve timing control system inspection. (See VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION INSPECTION ). Does variable valve timing control system work properly?	Yes	Go to the next step.
10		No	Repair or replace malfunctioning part according to variable valve timing control system inspection results.
11	Is engine compression correct? (See COMPRESSION INSPECTION [AJ] ).	Yes	Inspect valve timing.
11		No	Inspect for cause.
12	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Inspect 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 as necessary. Repeat Step 1.
2	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
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 M-MDS to DLC-2. Access ECT PID. Warm up engine and run it at idle. Verify ECT PID is correct. (See PCM INSPECTION [AJ] ). Is ECT PID correct?	Yes	Go to the next step.
4		No	Inspect for coolant leakage. Inspect cooling fan and operation or thermostat operation.
5	Perform spark test. (See SPARK TEST ). Is strong blue spark visible at each cylinder?	Yes	Inspect for the following: Spark plugs malfunction CMP sensor is installed improperly. Damage of trigger wheel on camshaft Open or short circuit on CMP sensor Open or short circuit between CMP sensor and PCM terminal 2AE, 2AD, 2AB or 2AA. Repair or replace malfunctioning part. If normal, go to the next step.
5		No	Repair or replace malfunctioning part according to spark test results.
6	Install fuel pressure gauge between plastic fuel hose and fuel distributor. Start engine and run it at idle. Measure fuel line pressure at idle. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct at idle?	Yes	Go to the next step.
6		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
7	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
7	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
8	Inspect for fuel saturation inside charcoal canister. Is excess amount of liquid fuel present in canister?	Yes	Replace charcoal canister.
8		No	Inspect fuel tank vent system. Then, go to the next step.
9	Inspect WU-TWC. Is WU-TWC normal?	Yes	Inspect EGR system.
9	Inspect WU-TWC. Is WU-TWC normal?	No	Replace WU-TWC.
10	Inspect for restriction in the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
10		No	Go to the next step.
11	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
1	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
2	Verify following: No external leakage Proper dipstick Proper engine oil viscosity Are all items normal?	Yes	Inspect internal engine parts such as valves, valve guides, valve stem seals, cylinder head drain passage, and piston rings.
2		No	Service as necessary. Repeat Step 2.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		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 as necessary. Repeat Step 1.
2	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
2		No	No DTC is displayed: Go to the next step.
3	Start engine and run it at idle speed. Turn A/C switch on. Does A/C compressor engage?	Yes	Go to step 5.
3		No	Inspect the following and repair or replace as necessary: Refrigerant charging amount Open circuit between A/C relay and PCM terminal 1AW Seized A/C magnetic clutch A/C magnetic clutch malfunction If all items are normal, Inspect the following: Refrigerant pressure switch operation Evaporator temperature sensor and A/C amplifier A/C switch is stuck open. Open or short circuit between refrigerant pressure switch and PCM terminal 1AN Open circuit of blower motor fan switch and resistor (if blower motor does not operate)
4	Start engine and run it at idle speed. Turn A/C switch on and set blower fan any speed. Do cooling fan and condenser fan operate?	Yes	Go to the next step.
4		No	Cooling fan motor does not operate: Inspect for following: Cooling fan motor malfunction Cooling fan motor GND open circuit Open circuit between cooling fan motor and fan control module Condenser fan motor does not operate: Inspect for the following: Condenser fan motor malfunction Condenser fan motor GND open circuit Open circuit between condenser fan motor and fan control module Both cooling fan and condenser fan do not operate: Inspect for the following: Fan control module malfunction Fan control module GND open circuit Open circuit between fan control module and cooling fan relay
5	Is drive belt normal?	Yes	Go to the next step.
5	Is drive belt normal?	No	Replace drive belt.
6	Is there any leakage around heater unit in passenger compartment?	Yes	Inspect and service heater for leakage.
6		No	Go to the next step.
7	Is there any leakage at coolant hoses and/or radiator?	Yes	Replace malfunctioning part.
7	Is there any leakage at coolant hoses and/or radiator?	No	Go to the next step.
8	Cool down engine. Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [L3, AJ] ). (See THERMOSTAT INSPECTION [L3, AJ] ). Is thermostat normal?	Yes	Engine coolant temperature and thermostat are normal. Inspect engine block for leakage or blockage.
8		No	Access ECT PID on M-MDS. Inspect 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.
9	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Is customer complaint "Lack of passenger compartment heat" only?	Yes	Inspect A/C and heater systems.
1		No	Go to the next step.
2	Does engine speed continue at fast idle?	Yes	Go to symptom troubleshooting " NO. 9 FAST IDLE/RUNS ON ".
2	Does engine speed continue at fast idle?	No	Go to the next step.
3	Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [L3, AJ] ). (See THERMOSTAT INSPECTION [L3, AJ] ). Is thermostat normal?	Yes	Go to the next step.
3		No	Replace thermostat. (See THERMOSTAT REMOVAL/INSTALLATION [L3, AJ] ).
4	Inspect fan control system operation. Does fan control system work properly?	Yes	Access ECT PID using 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 instrument cluster and related harnesses.
4		No	Repair or replace malfunctioning part.
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	What color is smoke coming from 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 PCV valve. Does PCV valve rattle?	Yes	Inspect for the following: Damaged valve guide, stems or valve seals Blocked oil drain passage in cylinder head Piston rings are not seated, seized or worn. Damaged cylinder bore If Other driveability symptoms are present, return to diagnostic index to service any additional symptoms.
2	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
3	Does cooling system hold pressure?	Yes	Inspect for the following: Cylinder head gasket leakage Intake manifold gasket leakage Engine block cracks or porosity If other driveability symptoms are present, return to diagnostic index to service any additional symptoms.
3	Does 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 as necessary. Repeat Step 4.
5	Connect M-MDS to DLC-2. Turn ignition switch to ON position. Retrieve any DTC. Are there any DTCs displayed?	Yes	DTC displayed: Go to appropriate DTC test.
5		No.	No DTC displayed: Go to the next step.
6	Install fuel pressure gauge between fuel filter and fuel distributor. Start engine and run it at idle. Measure fuel line pressure at idle. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct at idle?	Yes	Go to the next step.
6		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
7	Perform spark test. (See SPARK TEST ). Is strong blue spark visible at each cylinder?	Yes	Inspect spark plugs and CMP sensor. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [AJ] ).
7		No	Repair or replace malfunctioning part according to results of spark test.
8	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	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 to OFF position?	Yes	Go to the next step.
1		No	Inspect fuel injector. (See FUEL INJECTOR INSPECTION [AJ] ). If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
2	Inspect for blockage/restriction or open circuit between engine vacuum port and charcoal canister. Inspect for blockage in fuel tank vent system. Is fault indicated?	Yes	Replace vacuum hose.
2		No	Go to the next step.
3	Inspect purge solenoid valve. (See PURGE SOLENOID VALVE INSPECTION [L3, AJ] ). Is solenoid operating properly?	Yes	Go to the next step.
3		No	Replace purge solenoid valve.
4	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
4		No	No DTC is displayed: Inspect charcoal canister for fuel saturation. If excess amount of liquid fuel present, replace charcoal canister.
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Is squeal, click or chirp sound present?	Yes	Inspect engine oil level or drive belts.
1	Is squeal, click or chirp sound present?	No	Go to the next step.
2	Is rumble or grind sound present?	Yes	Inspect drive belt.
2	Is rumble or grind sound present?	No	Go to the next step.
3	Is rattle sound present?	Yes	Inspect location of rattle for loose parts.
3	Is rattle sound present?	No	Go to the next step.
4	Is hiss sound present?	Yes	Inspect for the following: Vacuum leakage Spark plug loose Intake-air system leakage VAD control system operation
4	Is hiss sound present?	No	Go to the next step.
5	Is rap or roar sound present?	Yes	Inspect exhaust system for loose parts.
5	Is rap or roar sound present?	No	Go to the next step.
6	Is knock sound present?	Yes	Go to symptom troubleshooting "No.13 Knocking/pinging".
6	Is knock sound present?	No	If noise comes from engine internal, inspect for friction gear, timing chain or HLA noise.
7	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Inspect the following components for loose attaching bolts or worn parts: Cooling fan Condenser fan Drive belt and pulleys Engine 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. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
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 terminal of A/C magnetic clutch connector? Specification More than 10.5 V	Yes	Inspect for GND condition of magnetic clutch on A/C compressor. If GND condition is normal, inspect for open circuit of magnetic clutch coil.
2		No	Go to the next step.
3	Disconnect refrigerant pressure switch connector. Connect jumper wire between terminals B and C (high and low pressure side) of refrigerant pressure switch connector. Start engine and run it at idle. Turn A/C switch on and set blower fan at 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 between refrigerant pressure switch and PCM terminal 1AN Open circuit of blower motor fan switch and resistor (if blower motor does not operate) Inspect evaporator temperature sensor and A/C amplifier
4	Remove jumper wire from switch connector. Reconnect connector to refrigerant pressure switch. Start engine and turn A/C switch on. Does fan operate?	Yes	Inspect for the following: A/C relay is stuck open. Open circuit between A/C relay and PCM terminal 1AW
4		No	Inspect for the following and repair or replace if necessary: Refrigerant charging amount A/C compressor for being seized
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
1		No	No DTC is displayed: Go to the next step.
2	Start engine and run it at idle. Turn A/C switch on. Remove A/C relay. Does A/C magnetic clutch disengage?	Yes	Inspect for the following: A/C relay is stuck closed. Short to GND circuit between A/C relay and PCM terminal 1U If both items are normal, go to the next step.
2		No	Inspect if circuit between A/C relay and magnetic clutch shorts to battery power circuit. If circuit is normal, inspect magnetic clutch stuck engagement or clearance.
3	Disconnect refrigerant pressure switch connector. Start the engine and A/C switch on. NOTE: A/C should not work when the connector disconnected. If A/C remains working, short to GND circuit may be present. Does A/C remain working?	Yes	Inspect for short to GND circuit between refrigerant pressure switch and PCM terminal 1AN.
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 the A/C switch is turned off. If A/C remains on, short to GND circuit may be present. Does ACSW PID reading remain on?	Yes	Inspect for the following: Short to GND circuit between A/C switch and A/C amplifier Short to GND circuit between A/C amplifier and refrigerant pressure switch
4		No	Inspect for stuck closed A/C switch.
5	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

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

NOTE
A/C should not work when the A/C switch is turned off. If A/C remains on, short to GND circuit may be present.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Does A/C compressor disengage when A/C switch is turned off?	Yes	Go to the next step.
1		No	Go to symptom troubleshooting " NO. 24 A/C ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY ".
2	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
2		No	No DTC is displayed: Inspect accelerator position sensor for proper adjustment.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Are any driveability or exhaust smoke concerns present?	Yes	Go to appropriate flow chart.
1	Are any driveability 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 as necessary. Repeat Step 2.
3	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTC. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
3		No	No DTC is displayed: Go to the next step.
4	Install fuel pressure gauge between plastic fuel hose and fuel distributor. Start engine and run it at idle. Inspect fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct at idle?	Yes	Go to the next step.
4		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
5	Inspect charcoal canister for fuel saturation. Is excess amount of liquid fuel present in canister?	Yes	Replace charcoal canister.
5		No	Inspect fuel tank vent system. If fuel tank vent system is normal, since sulfur content can vary in different fuels, try a different brand. If fuel tank vent system is not normal, repair or replace malfunctioning part.
6	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2 Turn ignition switch to ON position (Engine OFF). Retrieve DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
1		No	No DTC is displayed: Go to the next step.
2	Remove fuel-filler pipe. Make sure non-return valve is installed properly. Inspect non-return valve operation. Is non-return valve normal?	Yes	Inspect for the following: Improper use of fuel nozzle Inadequate fuel filling speed
2		No	Non-return valve is installed improperly: Reinstall non-return valve to proper position. Non-return valve does not operate properly: Replace non-return valve.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2. Turn ignition switch to ON position (Engine OFF). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC test.
1		No	No DTC displayed: Go to the next step.
2	Remove fuel-filler pipe. Make sure non-return valve is installed properly. Inspect non-return valve operation. Is non-return valve normal?	Yes	Inspect for the following: Improper use of fuel nozzle Fuel-filler pipe is not inserted correctly. Inspect fuel shut-off valve.
2		No	Non-return valve is installed improperly: Reinstall non-return valve to proper position. Non-return valve does not operate properly: Replace non-return valve.
3	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Remove all 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	Is spark plug wet/covered with carbon by engine oil?	Yes	Working up and down inspect all areas related to oil.
2	Is spark plug wet/covered with carbon by engine oil?	No	Go to the next step.
3	Inspect spark plug for the following: Cracked insulator Heat range Air gap Worn electrode Is spark plug normal?	Yes	Go to the next step.
3		No	Replace spark plug.
4	Inspect compression pressure at suspected faulty cylinder. Is engine compression correct? (See COMPRESSION INSPECTION [AJ] ).	Yes	Go to the next step.
4		No	Repair or replace malfunctioning part.
5	Install all spark plugs. Perform spark test at suspected faulty cylinder. Is strong blue spark visible? (Compare with normal cylinder).	Yes	Go to the next step.
5		No	Repair or replace malfunctioning parts.
6	Install fuel pressure gauge between fuel filter and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. (See AFTER REPAIR PROCEDURE [L3, AJ] ). Turn ignition switch to ON position (Engine OFF). Inspect fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Is fuel line pressure correct with ignition switch at ON position?	Yes	Inspect fuel injector for the following: Open or short in injector Leakage Injection volume
6		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
7	Inspect spark plug for the following: Heat range Air gap Is spark plug normal?	Yes	Go to the next step.
7		No	Replace spark plug. (See SPARK PLUG INSPECTION [L3, AJ] ).
8	Remove suspected fuel injector. Inspect for the following: Resistance (See FUEL INJECTOR INSPECTION [AJ] ). Fuel injection volume (See FUEL INJECTOR INSPECTION [AJ] ). Are all above items normal?	Yes	Inspect for open circuit between suspected fuel injector terminals and PCM at the following terminals: For #1 cylinder: 2I For #2 cylinder: 2J For #3 cylinder: 2K For #4 cylinder: 2E For #5 cylinder: 2F For #6 cylinder: 2G
8		No	Replace fuel injector. (See FUEL INJECTOR REMOVAL/INSTALLATION [AJ] ).
9	Is air cleaner element free of restriction?	Yes	Go to the next step.
9	Is air cleaner element free of restriction?	No	Replace air cleaner element.
10	Perform spark test. Is strong blue spark visible at each cylinder?	Yes	Go to the next step.
10		No	Repair or replace malfunctioning part.
11	Install fuel pressure gauge between fuel filter and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. (See AFTER REPAIR PROCEDURE [L3, AJ] ). Turn ignition switch to ON position (Engine OFF). Is fuel line pressure correct with ignition switch at ON position. (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
11		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
12	Inspect the following PIDs: ECT O2S11 O2S21 MAF O2S12 O2S22 (See PCM INSPECTION [AJ] ). Are PIDs normal?	Yes	Go to the next step.
12		No	Repair or replace malfunctioning part.
13	Perform purge control inspection (when engine can be started). Is purge control correct?	Yes	Go to the next step.
13		No	Repair or replace malfunctioning part.
14	Perform compression inspection. (See COMPRESSION INSPECTION [AJ] ). Is compression correct?	Yes	Inspect for clogging in exhaust system.
14		No	Repair or replace malfunctioning part.
15	When engine cannot be started, inspect intake-air system for air leakage. When engine can be started, perform intake manifold vacuum inspection. Is air sucked in from intake-air system?	Yes	Repair or replace malfunctioning part.
15		No	Go to the next step.
16	Install fuel pressure gauge between fuel filter and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. (See AFTER REPAIR PROCEDURE [L3, AJ] ). Turn ignition switch to ON position (Engine OFF). Is fuel line pressure correct with ignition switch at ON position? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Inspect the following PIDs: ECT O2S11 O2S21 MAF O2S12 O2S22 (See PCM INSPECTION [AJ] ). Inspect PCM GND condition.
16		No	Zero or low: Inspect fuel pump relay and fuel pump related circuit. Inspect for clogged fuel line. If normal, replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ). High: Replace fuel pump unit (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3, AJ] ).
17	Verify test results. If normal, return to diagnostic index to service any additional symptoms. 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, reprogram PCM if later calibration is available. Retest.

DIAGNOSTIC PROCEDURE

Intake Manifold Vacuum Inspection

Verify air intake hoses are installed properly.
Start the engine and run it at idle.
Measure the manifold vacuum using a vacuum gauge. If not as specified, inspect following: Air suction at throttle body, intake manifold and PCV valve installation points EGR valve (struck open) Fuel injector insulator Engine compression (See «COMPRESSION INSPECTION [AJ]»(ref-288768-S21041418302008062500000) ).

Engine coolant temperature compensation inspection

Connect the M-MDS to the DLC-2.
Select the PID/DATA MONITOR AND RECORD function on the M-MDS display.
Select the following PIDs. ECT IAT RPM
Verify that the engine is in cold condition, then start the engine.
Verify that the engine speed decreases as the engine warm-up. If the engine speed does not decrease or decreases slowly, inspect the following: ECT sensor and related harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [AJ]»(ref-288754-S26696853022008062500000) ). Throttle body and related harness (See «THROTTLE ACTUATOR INSPECTION [AJ]»(ref-288770-S33943809632008062500000) ). (See «THROTTLE POSITION (TP) SENSOR INSPECTION [AJ]»(ref-288754-S25532651392008062500000) ).

Load compensation inspection

Start the engine and run is at idle.
Connect the M-MDS to the DLC-2.
Verify that P0506, P0507 or P0511 are not displayed. If P0506, P0507 or P0511 are displayed, perform DTC inspection. (See «DTC TABLE [AJ]»(ref-288776-S26157273642008062500000) ).
Select 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 not as specified at specific load condition, inspect the following: A/C switch and related harness (See «CLIMATE CONTROL UNIT INSPECTION [L3, AJ]»(ref-288779-S15624579652008062500000) ). Fan switch and related harness (See «CLIMATE CONTROL UNIT INSPECTION [L3, AJ]»(ref-288779-S15624579652008062500000) ). PSP switch and related harness (See «POWER STEERING PRESSURE (PSP) SWITCH INSPECTION [AJ]»(ref-288754-S00672863252008062500000) ). Idle speed ENGINE SPEED Condition Engine speed (RPM) (1) No load 700-600 Electrical loads (2) ON 700-800 P/SON 700-800 A/CON 700-800 (1) Excludes temporary idle speed drop just after the electrical loads are turned on. (2) Blower motor is operating at high speed. Headlight switch is turned on. Rear window defroster switch is turned on. Cooling fans are operating.

Throttle position (TP) sweep inspection

Connect the M-MDS to the DLC-2.
Turn ignition switch to ON position.
Verify that following DTCs are not displayed: P0121, P0122, P0123, P0221, P0222, P0223, P2100, P2101, P2102, P2103, P2107, P2108, P2119, P2122, P2123, P2127, P2128, P2135, P2136 If any DTC is displayed, perform DTC inspection. (See «DTC TABLE [AJ]»(ref-288776-S26157273642008062500000) ).
Access TP_REL PID.
Verify that the PID reading is within the CTP value. (See «PCM INSPECTION [AJ]»(ref-288754-S26268951352008062500000) ). If the PID reading is out of range, perform the following: Remove air duct from throttle body. Verify that throttle valve moves when the accelerator pedal is depressed. If the throttle valve moves, inspect the following: TP sensor and related harness If the throttle valve does not move, inspect the following: Throttle actuator control motor and related harness
Gradually move the throttle valve and verify that the PID reading increases linearly. If the PID reading drops momentarily, inspect the following: TP sensor
Fully depress the accelerator pedal and verify that the PID reading is within the WOT value. (See «PCM INSPECTION [AJ]»(ref-288754-S26268951352008062500000) ). If the PID reading is out of range, perform the following: Remove air duct from throttle valve body. Verify that the throttle valve moves when the accelerator pedal is depressed. If the throttle valve moves, inspect the TP sensor and related harness. If the throttle valve does not move, inspect the throttle actuator control motor and related harness.

Fuel Cut Control System Inspection

Warm-up engine and let it idle.
Turn off the electrical loads and A/C switch.
Connect the M-MDS to the DLC-2.
Select RPM PID.
Listen for the fuel injector operation sound at all cylinders using the soundscope and monitor PID 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 when the accelerator pedal is released and starts again when the engine speed drops below 1,200 RPM. If not as specified, inspect the following: ECT sensor and related harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [AJ]»(ref-288754-S26696853022008062500000) ). Neutral/clutch switch and related harness (MTX) (See «CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [AJ]»(ref-288754-S07861137252008062500000) ). TR switch and related harness (ATX) (See «TRANSAXLE RANGE (TR) SWITCH INSPECTION [AW6A-EL]»(ref-288757-S03234523822008062500000) ).

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 Wiring harness and connectors (Main relay-fuel pump relay-PCM terminal 1V)
If operation sound is not heard, inspect the following

Scheme 144

Scheme 144: Ignition Timing Control Inspection

Start the engine and run it at idle.
Warm up the engine to normal operating temperature.
Connect the M-MDS to the DLC-2.
Select the PID/DATA MONITOR AND RECORD function on the M-MDS display.
Select the SPARKADV PID.
Verify that SPARKADV PID is within the specification. Specification Approx. BTDC 10°
Increase the engine speed and verify that the SPARKADV PID value is advanced. If it is not advanced, inspect the following: CKP sensor and related harness (See «CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [AJ]»(ref-288754-S31339880822008062500000) ). MAF sensor and related harness (See «MASS AIR FLOW (MAF) SENSOR INSPECTION [AJ]»(ref-288754-S01698417142008062500000) ). CMP sensors (left and right bank) and related harness (See «CAMSHAFT POSITION (CMP) SENSOR INSPECTION [AJ]»(ref-288754-S21129341882008062500000) ).

Spark Test

Disconnect the fuel pump relay.
Verify that each ignition 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 Step 1.
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 circuit: 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 2BB Ignition coil No.5 terminal B-PCM terminal 2BC Ignition coil No.6 terminal B-PCM terminal 2BD Are wiring harnesses normal?	Yes	Inspect and replace ignition coil. (See IGNITION COIL INSPECTION [L3, AJ] ).
4		No	Repair or replace malfunctioning part, then go to Step 1.
5	Measure voltage at terminal A in each ignition coil. Is voltage B+ ?	Yes	Go to the next step.
5		No	Inspect power supply circuit of ignition coils.
6	Do PCM connector or ignition coil connectors have poor connection?	Yes	Repair or replace connector, then go to Step 1.
6		No	Go to the next step.
7	Are the following parts normal? CKP sensor and crankshaft pulley PCM terminal 2Z or 2Y voltage Specification Approx. 1.5 V	Yes	Inspect for open or short in wiring harness and connector of CKP sensor.
7		No	Repair or replace malfunctioning part, then go to Step 1.

DIAGNOSTIC PROCEDURE

EGR Control System Inspection

Verify that EGR valve operation (initial operation) sound is heard when the ignition switch is turned to ON position. If the operation sound is not heard, connect M-MDS to the DLC-2 and verify that the DTC P0403 is shown. Perform DTC inspection. (See «DTC TABLE [AJ]»(ref-288776-S26157273642008062500000) ).
Start the engine and run it at idle.
Warm-up the engine to normal operating temperature.
Select the following PIDs: ECT RPM SEGRP APP1 APP2 TP_REL VSS
Let the vehicle idle and verify that the SEGRP value is 0 .
Put the vehicle in drive.
Depress the accelerator pedal and verify that the SEGRP value increases. If the SEGRP value does not increase, inspect the VSS, APP1, APP2, TP_REL and ECT PIDs. (See «PCM INSPECTION [AJ]»(ref-288754-S26268951352008062500000) ). If the SEGRP value does increases, inspect the following: EGR valve (Stuck open or close) Wiring harness and connectors (Main relay-EGR valve-PCM)
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 1BF) 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 displayed. Perform DTC inspection. (See «DTC TABLE [AJ]»(ref-288776-S26157273642008062500000) ).
Turn ignition switch to ON position.
Select ECT PID.
Verify that the engine coolant temperature is 60°C {140°F} or above. If M-MDS indicates less than 60°C {140°F} , perform the ECT sensor inspection. (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [AJ]»(ref-288754-S26696853022008062500000) ).
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 with engine speed at approx. 2,000 RPM for more than 30 s.
Put a finger to the purge solenoid valve and verify that there is no vacuum applied. If there is no vacuum, inspect the following: Wiring harness and connector (Main relay-purge solenoid valve-PCM terminal 1BF) Purge solenoid valve MAF, APP1, APP2, TP_REL 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 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-288778-S01465743672008062500000) ".
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 the following: A/C relay Open or short to GND circuit in wiring harness and connectors (Ignition switch - A/C relay-PCM terminal 1AW) A/C related parts APP1, APP2 PIDs

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 an 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.

EVAP system test description

Scheme 145

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_REF 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 EVAP gas leak occurred or not by reading the test results.

Scheme 146

Scheme 146: 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	EVAP control system leak detected (small leak)
P0446	Changeover valve (EVAP system leak detection pump) stuck close
P0455	EVAP control system leak detected (large leak)
P0456	EVAP control system leak detected (very small leak)
P2401	EVAP system leak detection pump control circuit low
P2402	EVAP system leak detection pump control circuit high
P2404	EVAP system leak detection pump sense circuit malfunction
P2405	EVAP system leak detection pump sense circuit low input
P2407	EVAP system leak detection pump sense circuit intermittent

DTC

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 SPECIFICATION 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 147

Scheme 147: EVAP system leak inspection using leak tester

Scheme 148

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 tester's operator manual for a more detailed self-test procedure. Verify that the control valve on the panel is in the HOLD position and 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 operator's manual.
Connect the SST to the vehicle. Verify that the control valve on the panel is in the HOLD position and open the nitrogen bottle valve. Remove the fuel-filler cap from the vehicle. If the fuel-filler cap is not a genuine part, replace it. Connect the receiver assembly ( SST: 134-01059) to the vehicle cap test hose assembly (part of SST ) and the fuel-filler cap from the vehicle. Connect the cap adaptor ( SST: 134-01058) 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 changeover 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 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 "SETTING LEAK STANDARD FOR TESTING" (.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 Control System (Aj): Diagnosis Mazda 6 GH

Inspection Method for Sensors

Scheme 139

SYMPTOM DIAGNOSTIC INDEX [AJ]

Scheme 140

Scheme 141

Scheme 142

Scheme 143

Diagnostic procedure

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

Scheme 144

Spark Test

EGR Control System Inspection

Purge Control System Inspection

A/C Cut-off Control System Inspection

Evaporative Emission (EVAP) System Leak Inspection

EVAP system leak inspection using M-MDS

Scheme 145

Scheme 146

Evaporative system test procedure

Scheme 147

Scheme 148

More articles — Symptom Troubleshooting - Engine Control System (Aj)

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