Symptom Troubleshooting - Engine Control System (L3): Diagnosis

SYMPTOM DIAGNOSTIC INDEX [L3]

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

No.	TROUBLESHOOTING ITEM		DESCRIPTION
1	Melting of main or other fuses
2	MIL illuminates		MIL is illuminated.
3	Will not crank		Starter does not work.
4	Hard to start/long crank/erratic start/erratic crank		Starter cranks engine at normal speed but engine requires excessive cranking time before starting.
5	Engine stalls.	After start/at idle	Engine stops unexpectedly at idle or after start or both.
6	Cranks normally but will not start		Starter cranks engine at normal speed but engine will not run.
7	Slow return to idle		Engine takes more time than normal to return to idle speed.
8	Engine runs rough/rolling idle		Engine speed fluctuates between specified idle speed and lower speed and engine shakes excessively.
9	Fast idle/runs on		Engine speed continues at fast idle after warm-up. Engine runs after ignition switch is turned to OFF.
10	Low idle/stalls during deceleration		Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.
11	Engine stalls/quits.	Acceleration/cruise	Engine stops unexpectedly at beginning of acceleration or during acceleration. Engine stops unexpectedly while cruising.
	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 is poor under load. (e.g., power down when climbing hills)
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)
14	Poor fuel economy		Fuel economy is unsatisfactory.
15	Emission compliance		Fails emissions test.
16	High oil consumption/leakage		Oil consumption is excessive.
17	Cooling system concerns	Overheating	Engine runs at higher than normal temperature/overheats.
18	Cooling system concerns	Runs cold	Engine does not reach normal operating temperature.
19	Exhaust smoke		Blue, black, or white smoke from exhaust system
20	Fuel odor (in engine compartment)		Gasoline fuel smell or visible leakage
21	Engine noise		Engine noise from under hood
22	Vibration concerns (engine)		Vibration from under hood or driveline
23	A/C does not work sufficiently.		A/C compressor magnetic clutch does not engage when A/C is turned on.
24	A/C is always on or A/C compressor runs continuously.		A/C compressor magnetic clutch does not disengage.
25	A/C is not cut off under WOT conditions.		A/C compressor magnetic clutch does not disengage under WOT.
26	Exhaust sulphur smell		Rotten egg smell (sulphur) from exhaust
27	Fuel refill concerns		Fuel tank does not fill smoothly.
28	Fuel filling shut off issues		Fuel does not shut off properly.
29	Spark plug condition		Incorrect spark plug condition
30.	ATX concerns	Upshift/downshift engagement	ATX concerns not related to engine performance

DIAGNOSTIC INDEX

Scheme 162

Scheme 162: CONTROL SYSTEM DEVICE AND CONTROL RELATIONSHIP CHART [L3]

Scheme 163

Scheme 163: QUICK DIAGNOSTIC CHART [L3]

Scheme 164

Scheme 165

Scheme 166

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: Inspect for open or short circuit for between following PCM terminal and instrument cluster. PCM terminal 1AI and instrument cluster terminal 2W PCM terminal 1AM and instrument cluster terminal 2X Inspect instrument cluster operation. See INSTRUMENT CLUSTER INSPECTION .
2	Verify test results. If okay, 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 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.
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 1AZ, 1BB, 1BD, 1BH and GND?	Yes	Go to the next step.
5		No	Repair or replace wiring harness.
6	Measure voltage between PCM GND terminals 1AZ, 1BB, 1BD, 1BH and coil terminal C. Is the 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. Access VPWR PID. Is VPWR PID normal? Specification Battery voltage	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 (harness-side)?	Yes	Go to the next step.
8		No	Repair or replace wiring harness between coil connector terminal D and fuse panel.
9	Inspect for the following wiring harnesses and connectors: Between coil terminal A and PCM terminal 1F. Between coil terminal B and PCM terminal 1E. Is there any malfunction?	Yes	Repair or replace wiring harness.
9		No	Go to the next step.
10	Is there continuity between PCM terminal 1B and starter relay with clutch pedal depressed (MTX with starter interlock system), P or N position (ATX)?	Yes	Go to the next step.
10		No	Repair or replace wiring harness.
11	Inspect the following: Battery connection Battery condition Transaxle is in Park or Neutral. (ATX) Clutch is fully depressed. (MTX) Fuses Are all items normal?	Yes	Go to the next step.
11		No	Service if necessary. Repeat Step 11.
12	Is clicking sound heard from starter when ignition switch is turned to START?	Yes	Go to step 17.
12		No	ATX: Go to next Step. MTX: Go to step 17.
13	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position. (Engine off) Access TR PID. Is TR PID indicated P/N when selecting P or N position?	Yes	Go to step 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 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 the next step.
18	Inspect starting system. (See STARTER INSPECTION [L3, AJ] ). Is starting system normal?	Yes	Inspect for seized/hydrolocked engine, flywheel or drive plate. (See FLYWHEEL INSPECTION [G35M-R, A65M-R] ).
18		No	Repair or replace components if required.
19	Do any other electrical accessories work?	Yes	Go to the next step.
19	Do any other electrical accessories work?	No	Inspect charging system. (See BATTERY INSPECTION [L3, AJ] ). (See GENERATOR INSPECTION [L3, AJ] ).
20	NOTE: The following test should be performed on ATX only. For MTX, go to the next step. Connect M-MDS to DLC-2.Access TR PID.Turn ignition switch to ON position.Is TR PID indicated P/N when selecting P or N position?	Yes	Go to the next step.
20		No	Inspect adjustment of TR switch. If TR switch is adjusted properly, inspect for open circuit between TR switch and TCM terminal 2H or starter.
21	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 the following: Open circuit between main relay and PCM terminal 1BE or 1AW (1) Open circuit between main relay terminal E and PCM terminal 1Q Main relay is stuck open. Open or poor GND circuit (PCM terminal 1AZ, 1BB, 1BD or 1BH) Poor connection of vehicle body GND
21		No	No DTC is displayed: Inspect the following: START circuit in ignition switch Open circuit between ignition switch and starter Starter interlock switch (MTX)
22	Verify test results. If okay, 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.
(1) California emission regulation applicable ATX model

NOTE
The following test should be performed on ATX only. For MTX, go to the next step.

(1)	California emission regulation applicable ATX model

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 if 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	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 parts.
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	Attempt to start engine at part throttle. Does engine run smoothly at part throttle?	Yes	Inspect electronic throttle control system operation.
8		No	Go to the next step.
9	Install fuel pressure gauge between fuel pipe and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. Turn ignition switch to ON position. Is fuel line pressure correct with ignition switch ON? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
9		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If okay, replace fuel pump unit. High: Replace fuel pump unit.
10	Is fuel line pressure held after ignition switch is turned OFF? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
10		No	Inspect fuel injector. If fuel injector is okay, replace fuel pump unit.
11	Disconnect a 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 is stuck open.
11		No	Go to the next step.
12	Inspect MAF sensor for contamination. Is there any contamination?	Yes	Replace MAF sensor.
12		No	Go to the next step.
13	Is there restriction in exhaust system?	Yes	Inspect exhaust system.
13	Is there restriction in exhaust system?	No	Go to the next step.
14	Inspect engine condition while tapping EGR valve housing. Does engine condition improve?	Yes	Replace EGR valve.
14		No	Go to the next step.
15	Inspect starting system. (See STARTER INSPECTION [L3, AJ] ). Is starting system normal?	Yes	Inspect for loose connectors or poor terminal contact. If okay, remove EGR valve and visually inspect for mechanically stuck EGR valve.
15		No	Repair or replace components as required.
16	Verify test results. If okay, 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 appears: Go to the next step.
2	Does engine stall after approx. 2 seconds since engine is started?	Yes	Go to the next step.
2		No	Immobilizer system is okay. 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 any of the following DTCs displayed? DTC B1213, B1342, B1600, 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 1AZ, 1BB, 1BD, 1BH and GND?	Yes	Go to the next step.
6		No	Repair or replace wiring harness.
7	Measure voltage between PCM GND terminals 1AZ, 1BB, 1BD, 1BH 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. Access VPWR PID. Is VPWR PID normal? VPWR PID Battery voltage	Yes	Go to the next step.
8		No	Repair or replace wiring harness.
9	Disconnect coil connector. Turn ignition switch to ON position. Is there battery voltage at coil connector terminal D?	Yes	Inspect for the following: Open or short circuit between coil terminal A and PCM terminal 1F. Open or short circuit between coil terminal B and PCM terminal 1E.
9		No	Repair or replace wiring harness between coil connector terminal D and fuse panel.
10	Verify the following: Vacuum connection Air cleaner element No air leakage from intake-air system No restriction of intake-air system Proper sealing of intake manifold and components attached to intake manifold: EGR valve Ignition wiring Fuel quality: proper octane, contamination, winter/summer blend Electrical connections Smooth operation of throttle valve Are all items normal?	Yes	Go to the next step.
10		No	Service if necessary. Repeat Step 10.
11	Turn ignition switch to OFF position. Disconnect TP sensor connector. Measure voltage at TP sensor connector terminal B with ignition switch ON. Voltage 4.5-5.5 V Is voltage normal?	Yes	Go to the next step.
11		No	Inspect and repair open or short circuit between PCM terminal 2AO and TP sensor terminal B.
12	Turn ignition switch to OFF position. Disconnect accelerator position sensor connector. Measure voltage at accelerator position sensor connector VREF terminals with ignition switch to ON position. Voltage 4.5-5.5 V Is voltage normal?	Yes	Go to the next step.
12		No	Inspect and repair open or short circuit for the following: PCM terminal 1AJ and accelerator position sensor terminal A PCM terminal 1AL and accelerator position sensor terminal D
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 the following: Open circuit between main relay and PCM terminal 1BE or 1AW (1) Open main relay terminal E and PCM terminal 1Q Main relay is stuck open. Open or poor GND circuit (PCM terminal 1AZ, 1BB, 1BD or 1BH) Poor connection of vehicle body GND
13		No	No DTC is displayed: Go to the next step.
14	Start engine at part throttle. Does engine run smoothly at part throttle?	Yes	Inspect electronic throttle control system operation. (See ELECTRONIC THROTTLE CONTROL SYSTEM INSPECTION ).
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 2W or 2AQ Open or short circuit in between CKP sensor and GND Open or short circuit in CKP sensor harnesses If CKP sensor and harness are okay, 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 parts.
17	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.
17		No	Repair suspected wiring harness.
18	Perform Spark Test. (See SPARK TEST ). Is the strong blue spark visible at each cylinder?	Yes	Go to the next step. If symptom occurs with A/C on, go to Step 23.
18		No	Repair or replace malfunctioning part according to spark test results.
19	Inspect spark plug condition. Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from injector. Spark plug is grayish white: Inspect 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 pipe and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. Turn ignition switch to ON position. Is fuel line pressure correct with ignition switch ON? (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 okay, replace fuel pump unit. High: Replace fuel pump unit.
23	Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service if necessary. Is fuel line pressure held after ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
23		No	Inspect fuel injector. If fuel injector is okay, replace fuel pump unit.
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 pressures.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 IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY ". For other symptoms, inspect the 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 sticks 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.
27		No	Go to the next step.
28	Inspect variable valve timing control system operation. (See VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION INSPECTION ). Does variable valve timing control work properly?	Yes	Go to the next step.
28		No	Repair or replace malfunctioning parts according to variable valve timing control system operation inspection results.
29	Is engine compression correct?	Yes	Inspect valve timing.
29	Is engine compression correct?	No	Inspect for cause.
30	Verify test results. If okay, 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.
(1) California emission regulation applicable ATX model

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

(1)	California emission regulation applicable ATX model

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Connect M-MDS to DLC-2. Do any of the following conditions appear? Engine does not completely start. DTC B1681 is displayed.	Yes	Both conditions appear: Go to Step 3.
1		No	Either or other condition appears: Go to the next step.
2	Does engine stall after approx. 2 s from when it is started?	Yes	Go to the next step.
2		No	Immobilizer system is okay. 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-MDSequivalent to DLC-2 and retrieve DTC. Are any of 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 1AZ, 1BB, 1BD, 1BH and GND?	Yes	Go to the next step.
6		No	Repair or replace wiring harness.
7	Measure voltage between PCM GND terminals 1AZ, 1BB, 1BD, 1BH 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. Access VPWR PID. Is VPWR PID normal? VPWR PID Battery voltage	Yes	Go to the next step.
8		No	Repair or replace wiring harness.
9	Disconnect coil connector. Turn ignition switch to ON position. Is there battery voltage at coil connector terminal D?	Yes	Inspect for the following: Open or short circuit between coil terminal A and PCM terminal 1F Open or short circuit between coil terminal B and PCM terminal 1E
9		No	Repair or replace wiring harness between coil connector terminal D and fuse panel.
10	Verify the following: Vacuum connection External fuel shut off or accessory (such as kill switch, alarm) Fuel quality: proper octane, contamination, winter/summer blend No air leakage from intake-air system 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 if necessary. Repeat Step 10.
11	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 the following: Open circuit between main relay and PCM terminal 1BE or 1AW (1) Open main relay terminal E and PCM terminal 1Q Main relay is stuck open. Open or poor GND circuit (PCM terminal 1AZ, 1BB, 1BD or 1BH) Poor connection of vehicle body GND
11		No	No DTC is displayed: Go to the next step.
12	Turn ignition switch to OFF position. Disconnect TP sensor connector. Measure voltage at TP sensor connector terminal B with ignition switch to ON position. Voltage 4.5-5.5 V Is voltage normal?	Yes	Go to the next step.
12		No	Inspect and repair open or short circuit between PCM terminal 2AO and TP sensor terminal B.
13	Turn ignition switch to OFF position. Disconnect accelerator position sensor connector. Measure voltage at accelerator position sensor connector VREF terminals with ignition switch to ON position. Voltage 4.5-5.5 V Is voltage normal?	Yes	Go to the next step.
13		No	Inspect and repair open or short circuit for the following: PCM terminal 1AJ and accelerator position sensor terminal A PCM terminal 1AL and accelerator position sensor terminal D
14	Does engine start with throttle closed?	Yes	Go to Step 29.
14	Does engine start with throttle closed?	No	Go to the next step.
15	Will engine start and run smoothly at part throttle?	Yes	Inspect electronic throttle control system operation. (See ELECTRONIC THROTTLE CONTROL SYSTEM INSPECTION ).
15	Will engine start and run smoothly at part throttle?	No	Go to the next step.
16	Connect M-MDS to DLC-2. Access RPM PID. Is RPM PID indicating engine speed when cranking engine?	Yes	Go to the next step.
16		No	Inspect for the following: Open or short circuit in CKP sensor Open or short circuit between CKP sensor and PCM terminal 2W or 2AQ Open or short circuit in between CKP sensor and GND Open or short circuit in CKP sensor harnesses If CKP sensor and harness are okay, go to the next step.
17	Visually inspect CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
17		No	Replace malfunctioning parts.
18	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.
18		No	Repair suspected wiring harness.
19	Perform Spark Test. (See SPARK TEST ). Is the strong blue spark visible at each cylinder?	Yes	Go to the next step.
19		No	Repair or replace malfunctioning part according to spark test results.
20	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.
20		No	Install spark plugs on original cylinders. Go to the next step.
21	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
21	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
22	Inspect for restriction in exhaust system.	Yes	Inspect exhaust system.
22	Inspect for restriction in exhaust system.	No	Go to the next step.
23	Install fuel pressure gauge between fuel pipe and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. Turn ignition switch to ON position. Is fuel line pressure correct when ignition switch is turned on/off five times ? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
23		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If okay, replace fuel pump unit. High: Replace fuel pump unit.
24	Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service if necessary. Is fuel line pressure held after ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
24		No	Inspect fuel injector. If fuel injector is okay, replace fuel pump unit.
25	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 sticks open mechanically. 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. Is engine condition improved?	Yes	Replace EGR valve.
27		No	Go to the next step.
28	Inspect variable valve timing control system operation. (See VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION INSPECTION ). Does variable valve timing control work properly?	Yes	Go to the next step.
28		No	Repair or replace malfunctioning parts.
29	Is engine compression correct?	Yes	Inspect valve timing.
29	Is engine compression correct?	No	Inspect for causes.
30	Verify test results. If okay, 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.
(1) California emission regulation applicable ATX model

(1)	California emission regulation applicable ATX model

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 okay. Go to the next step.
2		No	Access ECT PID on M-MDS. Inspect for both ECT PID and temperature gauge on instrument cluster readings. If temperature gauge on instrument cluster indicates normal range but ECT PID is not same as temperature gauge reading, inspect ECT sensor. If temperature gauge on instrument cluster indicates cold range but ECT PID is normal, inspect temperature gauge and heat gauge unit.
3	Is throttle body free of contamination?	Yes	Inspect for air leakage from intake-air system components while racing engine to higher speed.
3	Is throttle body free of contamination?	No	Clean or replace throttle body.
4	Verify test results. If okay, 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 (such as kill switch, alarm). Fuel quality (e.g. 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 if 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 idle it.Turn A/C switch on.Measure low side and high side pressures.Are 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 IS ALWAYS ON OR 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 idle it. Measure voltage at PCM terminal 2T. (See PCM INSPECTION [L3] ). Is voltage normal?	Yes	Go to the next step.
5		No	Inspect power steering pressure switch operation and wiring harness between P/S pressure switch connector 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 parts.
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 condition. Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from injector. Spark plug is grayish white: Inspect 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 SYSTEM 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 fuel pipe and fuel distributor. Start engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
10		No	Zero or low: Inspect for clogged fuel line. If okay, replace fuel pump unit. High: Replace fuel pump unit.
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 off? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
11		No	Inspect fuel injector. If fuel injector is okay, replace fuel pump unit.
12	Connect M-MDS to DLC-2. Start the engine and idle it. Access LONG FT1 PID. Measure LONG FT1 PID during idle. Is PID value between -14% and +14% ?	Yes	Go to the next step.
12		No	LONG FT1 PID is out of specification. Less than specification (too rich): Inspect EVAP control system. If system is okay, go to Step 14. Greater than specification (too lean): Inspect for air leakage at intake-air system components. If system is okay, 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	Check 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.
15	Inspect for restriction in exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
15		No	Go to the next step.
16	Visually inspect CMP sensor and teeth of camshaft. Are CMP sensor and teeth of camshaft normal?	Yes	Go to the next step.
16		No	Replace malfunctioning parts.
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	Inspect variable valve timing control system operation. (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 parts.
19	Is engine compression correct?	Yes	Inspect valve timing.
19	Is engine compression correct?	No	Inspect for causes.
20	Verify test results. If okay, 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-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	Connect the M-MDS to DLC-2. Inspect the value at the following PCM and TCM (ATX) PIDs. PCM PIDs: AC_REQ COLP CPP (MTX) CPP/PNP (MTX) PSP TCM PID: TR Are the PID values normal?	Yes	Go to the next step.
3		No	If the AC_REQ PID is not specified: Inspect A/C switch, refrigerant pressure switch (low/high) and fan switch. If the COLP PID is not specified: Inspect refrigerant pressure switch (middle). If the CPP PID is not specified: Inspect clutch switch. If the CPP/PNP PID is not specified: Inspect neutral switch. If the PSP PID is not specified: Inspect power steering pressure switch. If the TR PID is not specified: Inspect TR switch.
4	Is there air leakage felt or heard at intake-air system components while racing engine to higher speed?	Yes	Repair or replace parts if necessary.
4		No	Inspect the following: Electronic throttle control system operation Accelerator position sensor adjustment
5	Verify test results. If okay, 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 roughly?	Yes	Go to symptom troubleshooting " NO.8 ENGINE RUNS ROUGH/ROLLING IDLE ".
1	Does engine idle roughly?	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 IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY ."
2		No	Go to the next step.
3	Verify the following: Proper routing of and no damage to vacuum lines No air leakage from intake-air system Are all items normal?	Yes	Go to the next step.
3		No	Service if necessary. Repeat Step 3.
4	Connect M-MDS to DLC-2. Turn ignition switch to ON (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: Go to the next step.
5	Perform electronic throttle control system operation inspection. (See ELECTRONIC THROTTLE CONTROL SYSTEM INSPECTION ). Does electronic throttle control system 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 the following PCM and TCM (ATX) PIDs. PCM PIDs: APP1 APP2 BOO CPP (MTX) CPP/PNP (MTX) TP_REL MAF VSS TCM PID: TR VSS Drive the vehicle with monitoring PIDs. Are the PID values within specified?	Yes	Go to the next step.
7		No	If the APP1 or APP2 PID is not specified: Inspect accelerator position sensor. If the BOO PID is not specified: Inspect brake switch. If the CPP PID is not specified: Inspect clutch switch. If the CPP/PNP PID is not specified: Inspect neutral switch. If the TP_REL PID is not specified: Inspect TP sensor. If the MAF PID is not specified: Inspect MAF sensor. If the VSS PID for PCM is not specified: Inspect VSS sensor. (MTX without ABS) Inspect ABS wheel speed sensors, (except for MTX without ABS) If the TR PID is not specified: Inspect TR switch. If the VSS PID for TCM is not specified: Inspect VSS sensor.
8	Verify test results. If okay, 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: Vacuum connection Air cleaner element No air leakage from intake-air system No restriction of intake-air system Proper sealing of intake manifold and components attached to intake manifold: such as EGR valve Ignition wiring Fuel quality (e.g. proper octane, contamination, winter/summer blend) Electrical connections Smooth operation of throttle valve Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect 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	Connect M-MDS to DLC-2. Access the following PCM PIDs. APP1 APP2 RPM VPWR MAF TP_REL VSS Drive the vehicle with monitoring PIDs. Are the PID values within specified?	Yes	Go to the next step.
4		No	If APP1, APP2 PIDs is not specified: Inspect if output signal from accelerator position sensor changes smoothly. If RPM PID is not specified: Inspect CKP sensor and related harness for vibration or intermittent open/short circuit. If VPWR PID is not specified: Inspect for open circuit intermittently. If MAF PID is not specified: Inspect for open circuit of MAF sensor and related wire harness intermittently. If TP_REL PID is not specified: Inspect if output signal from TP sensor changes smoothly. If VSS PID is not specified: Inspect for open circuit of VSS and related wire harness intermittently.
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 parts.
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 SYSTEM INSPECTION ). Does electronic throttle control system work properly?	Yes	Go to the next step.
8		No	Repair or replace malfunctioning part according to electronic throttle 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 fuel pipe and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. Turn ignition switch to ON position. Is fuel line pressure correct with ignition switch to ON position? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	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 okay, replace fuel pump unit. High: Replace fuel pump unit.
11	Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service if necessary. Is fuel line pressure held after ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
11		No	Inspect fuel injector. If fuel injector is okay, replace fuel pump unit.
12	NOTE: The following test is for engine stalling 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 pressure.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 IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY ". For other symptoms, inspect the following: Refrigerant charging amount Condenser fan operation
13	NOTE: The following test should be performed for symptom with cruise control ON. If other symptoms exist, go to the next step. Inspect cruise control system.Is cruise control system normal?	Yes	Go to the next step.
13		No	Repair or replace malfunctioning parts.
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	Go to the next step. Inspect if purge solenoid valve sticks 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 Variable tumble system operation. (See VARIABLE TUMBLE SYSTEM OPERATION INSPECTION ). Is Variable tumble system normal?	Yes	Go to the next step.
16		No	Repair or replace malfunctioning parts.
17	Inspect EGR system. (See EGR CONTROL SYSTEM INSPECTION ). Is EGR system normal?	Yes	Go to the next step.
17		No	Replace malfunctioning parts.
18	Is engine compression correct?	Yes	Inspect the following: Valve timing Internal transaxle part (ATX) Clutch (MTX)
18	Is engine compression correct?	No	Inspect for cause.
19	Verify test results. If okay, 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 stalling with A/C on. If other symptom exists, go to the next step.

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

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Verify the following: Vacuum connection Air cleaner element No air leakage from intake-air system No restriction of intake-air system Proper sealing of intake manifold and components attached to intake manifold; such as EGR valve Fuel quality (e.g. proper octane, contamination, winter/summer blend) Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect 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	Connect M-MDS to DLC-2. Access the following PCM PIDs. APP1 APP2 RPM VPWR MAF TP_REL VSS Drive the vehicle with monitoring PIDs. Are the PID values within specified?	Yes	Go to the next step.
4		No	If APP1, APP2 PIDs is not specified: Inspect if output signal accelerator position sensor changes smoothly. If RPM PID is not specified: Inspect CKP sensor and related wiring harness for vibration or intermittent open/short circuit or both. If MAF PID is not specified: Inspect for intermittent open circuit of MAF sensor and related wiring harness. If TP_REL PID is not specified: Inspect if output signal TP sensor changes smoothly. If VSS PID is not specified: Inspect for intermittent open circuit of VSS and related wiring harness.
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 parts.
6	Inspect spark plug condition. Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Inspect spark plug and ignition coil related harness. 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 SYSTEM INSPECTION ). Does electronic throttle control system 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 exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
9		No	Go to the next step.
10	Install fuel pressure gauge between fuel pipe and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. Turn ignition switch to ON position. Is fuel line pressure correct with ignition switch to ON position? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	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 okay, replace fuel pump unit. High: Replace fuel pump unit.
11	Inspect Variable tumble system operation. (See VARIABLE TUMBLE SYSTEM OPERATION INSPECTION ). Does Variable tumble system work properly?	Yes	Go to the next step.
11		No	Repair or replace malfunctioning parts.
12	Inspect Variable intake air system operation. (See VARIABLE INTAKE AIR SYSTEM OPERATION INSPECTION ). Does Variable intake air system work properly?	Yes	Go to the next step.
12		No	Repair or replace malfunctioning parts.
13	NOTE: The following test is for engine stalling with A/C on concern. If other symptoms exist, 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.
13		No	If A/C is always on, go to symptom troubleshooting " NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY ". For other symptoms, inspect the following: Refrigerant charging amount Condenser fan operation
14	Inspect for A/C cut-off operation. (See A/C CUT-OFF CONTROL SYSTEM INSPECTION ). Does A/C cut-off work properly?	Yes	Go to the next step.
14		No	Inspect A/C cut-off system components.
15	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.
15		No	Go to the next step.
16	Visually inspect CMP sensor and projections of camshaft pulley. Are CMP sensor and projections of camshaft pulley normal?	Yes	Go to the next step.
16		No	Replace malfunctioning parts.
17	Inspect EGR system. (See EGR CONTROL SYSTEM INSPECTION ). Is EGR system normal?	Yes	Go to the next step.
17		No	Replace malfunctioning parts according to EGR control system operation inspection results.
18	Inspect variable valve timing control system operation. (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 parts according to variable valve timing control system inspection results.
19	Is engine compression correct?	Yes	Inspect the following: Valve timing Internal transaxle components (ATX) Clutch (MTX) Brake system for dragging
19	Is engine compression correct?	No	Inspect for cause.
20	Verify test results. If okay, 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 stalling with A/C on concern. If other symptoms exist, 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	Connect M-MDS to DLC-2. Access IAT and MAF PIDs. Monitor each PID. (See PCM INSPECTION [L3] ). Are PIDs normal?	Yes	Go to the next step.
2		No	If IAT PID is not specified : Inspect IAT sensor If MAF PID is not specified : Inspect MAF sensor
3	Connect M-MDS to DLC-2. Turn key to ON (engine off). 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?	Yes	Go to the next step.
4	Is engine compression correct?	No	Inspect for cause.
5	Install fuel pressure gauge between fuel pipe and fuel distributor. Start engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Inspect ignition timing.
5		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If okay, replace fuel pump unit. High: Replace fuel pump unit.
6	Inspect knock sensor. Is knock sensor normal?	Yes	Inspect ignition timing.
6	Inspect knock sensor. Is knock sensor normal?	No	Replace knock sensor.
7	Verify test results. If okay, 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 for the following: Air cleaner element for contamination ATF level (ATX) Fuel quality Coolant level Brake dragging Clutch slippage (MTX) Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect 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	Access ECT PID. Drive vehicle while monitoring PID. (See PCM INSPECTION [L3] ). Is PID within specification?	Yes	Go to the next step.
3		No	Inspect for coolant leakage, cooling fan and condenser fan operations or thermostat operation.
4	Perform spark test. (See SPARK TEST ). Is strong blue spark visible at each cylinder?	Yes	Inspect for the following: Spark plugs malfunction CMP sensor is improperly installed. Trigger wheel damage on camshaft Open or short circuit on CMP sensor Open or short circuit between CMP sensor and PCM terminal 2S or 2AM Open or short circuit between CMP sensor and GND. Repair or replace malfunctioning parts. If okay, go to the next step.
4		No	Inspect suspect ignition coil and connector.
5	Install fuel pressure gauge between fuel pipe and fuel distributor. Start engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	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 okay, replace fuel pump unit High: Replace fuel pump unit.
6	Inspect for Variable tumble system operation. (See VARIABLE TUMBLE SYSTEM OPERATION INSPECTION ). Does Variable tumble system work properly?	Yes	Go to the next step.
6		No	Repair or replace malfunctioning parts.
7	Inspect for variable valve timing control system operation. (See VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION INSPECTION ). Does variable valve timing control system work properly?	Yes	Go to the next step.
7		No	Repair or replace malfunctioning parts.
8	Inspect for Variable intake air system operation. (See VARIABLE INTAKE AIR SYSTEM OPERATION INSPECTION ). Does Variable intake air system work properly?	Yes	Go to the next step.
8		No	Repair or replace malfunctioning parts.
9	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
9	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
10	Inspect for restriction in the exhaust system. Is there any restriction?	Yes	Inspect exhaust system.
10		No	Go to the next step.
11	Inspect for contaminated MAF sensor. Is there any contamination?	Yes	Go to the next step.
11		No	Inspect for cause.
12	Inspect MAF sensor for contamination. Is there any contamination?	Yes	Replace MAF sensor.
12		No	Go to the next step.
13	Is engine compression correct?	Yes	Inspect valve timing.
13	Is engine compression correct?	No	Inspect for cause.
14	Verify test results. If okay, 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 for following: Vacuum lines for leakage or blockage Electrical connections Proper maintenance schedule followed Intake-air system and air cleaner element concerns: obstructions, leakage or dirtiness Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect 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 idle it. Verify ECT PID is correct. (See PCM INSPECTION [L3] ). Is ECT PID correct?	Yes	Go to the next step.
4		No	Inspect for coolant leakage, cooling fan and condenser fan operation or thermostat operation.
5	Perform Spark Test. (See SPARK TEST ). Is the strong blue spark visible at each cylinder?	Yes	Inspect for the following: Spark plugs malfunction Improperly installed CMP sensor Damage of trigger wheel on camshaft Open or short circuit on CMP sensor Open or short circuit between CMP sensor and PCM terminal 2S or 2AM Open or short circuit between CMP sensor and GND Repair or replace malfunctioning parts. If okay, go to the next step.
5		No	Inspect suspect ignition coil and connector.
6	Install fuel pressure gauge between fuel pipe and fuel distributor. Start engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
6		No	Zero or low: Inspect for clogged fuel line. If okay, replace fuel pump unit. High: Replace fuel pump unit.
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	Is there restriction in exhaust system?	Yes	Inspect exhaust system.
9	Is there restriction in exhaust system?	No	Go to the next step.
10	Inspect three-way catalytic converter. Is three-way catalytic converter normal?	Yes	Inspect EGR system. (See EGR CONTROL SYSTEM INSPECTION ).
10		No	Replace three-way catalytic converter.
11	Verify test results. If okay, 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	Inspect for the following: 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 if necessary. Repeat Step 2.
3	Verify test results. If okay, 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 if 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 and set blower fan to any speed. Does A/C compressor engage?	Yes	Go to Step 5.
3		No	Inspect for the following and repair or replace if necessary: Refrigerant charging amount Open circuit between A/C relay and PCM terminal 1I Seized A/C magnetic clutch A/C magnetic clutch malfunction If all items are okay, go to the next step.
4	Start the engine and run it at idle speed. Access AC_REQ PID using M-MDS. Turn A/C switch on and set blower fan any speed. Does the PID turn ON and OFF properly? (See PCM INSPECTION [L3] ).	Yes	Go to the next step.
4		No	Inspect the following: Refrigerant pressure switch operation A/C switch is stuck open. Open or short circuit between refrigerant pressure switch and PCM terminal 1AU Open circuit of blower motor fan switch and resistor (if blower motor does not operate) Evaporator temperature sensor and A/C amplifier
5	Inspect cooling fan control system operation. (See COOLING FAN CONTROL SYSTEM INSPECTION ). Does cooling fan control system work properly?	Yes	Go to the next step.
5		No	Repair or replace malfunctioning parts.
6	Is drive belt normal?	Yes	Go to the next step.
6	Is drive belt normal?	No	Replace drive belt.
7	Is there any leakage around heater unit in passenger compartment?	Yes	Inspect and service heater for leakage.
7		No	Go to the next step.
8	Is there any leakage at coolant hoses and/or radiator?	Yes	Replace malfunctioning part.
8	Is there any leakage at coolant hoses and/or radiator?	No	Go to the next step.
9	Cool down the engine. Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [L3, AJ] ). (See THERMOSTAT INSPECTION [L3, AJ] ). Is thermostat normal?	Yes	Engine coolant temperature and thermostat are okay, inspect engine block for leakage or blockage.
9		No	Access ECT PID. Inspect for both ECT PID and temperature gauge readings. If temperature gauge on instrument cluster indicates normal range but ECT PID is not same as temperature gauge reading, inspect ECT sensor. If temperature gauge on instrument cluster indicates overheating but ECT PID is normal, inspect temperature gauge and heat gauge unit.
10	Verify test results. If okay, 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 system.
1		No	Go to the next step.
2	Does engine speed continue during fast idle?	Yes	Go to symptom troubleshooting " NO.9 FAST IDLE/RUNS ON ".
2	Does engine speed continue during 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.
4	Inspect cooling fan control system operation. (See COOLING FAN CONTROL SYSTEM INSPECTION ). Does cooling fan control system work properly?	Yes	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.
4		No	Repair or replace malfunctioning part.
5	Verify test results. If okay, 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 ring is 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 Cracked or porous engine block 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 if necessary. Repeat Step 4.
5	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.
5		No	No DTC is displayed: Go to the next step.
6	Install fuel pressure gauge between fuel pipe and fuel distributor. Start engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
6		No	Zero or low: Inspect for clogged fuel line. If okay, replace fuel pump unit. High: Replace fuel pump unit.
7	Perform Spark Test. (See SPARK TEST ). Is the strong blue spark visible at each cylinder?	Yes	Inspect spark plugs and CMP sensor.
7		No	Repair or replace malfunctioning part according to spark test results.
8	Verify test results. If okay, 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. Install fuel pressure gauge between fuel pipe and fuel distributor. Start engine and idle it. Measure fuel line pressure during idle. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	Yes	Go to the next step.
1		No	Replace fuel pump unit.
2	Inspect for blockage/restriction or opening 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 is present, replace charcoal canister.
5	Verify test results. If okay, 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 grinding noise present?	Yes	Inspect drive belts.
2	Is rumble or grinding noise present?	No	Go to the next step.
3	Is rattle noise present?	Yes	Inspect location of rattle for loose parts.
3	Is rattle noise present?	No	Go to the next step.
4	Is hissing noise present?	Yes	Inspect for following: Vacuum leakage Spark plug looseness Intake-air system leakage Variable air duct (VAD) control system operation (See VARIABLE AIR DUCT (VAD) CONTROL SYSTEM OPERATION INSPECTION ).
4	Is hissing noise present?	No	Go to the next step.
5	Is rap or roar noise present?	Yes	Inspect exhaust system for loose parts.
5	Is rap or roar noise present?	No	Go to the next step.
6	Is knocking noise present?	Yes	Go to symptom troubleshooting " NO.11 KNOCKING/PINGING ".
6	Is knocking noise present?	No	If noise comes from engine internal, inspect for friction gear, timing chain or MLA noise.
7	Verify test results. If okay, 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 okay, 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 compressor magnetic clutch connector? Specification 10.5 V or more	Yes	Inspect for GND condition of magnetic clutch on A/C compressor. If GND condition is okay, inspect for open circuit magnetic clutch coil.
2		No	Go to the next step.
3	Disconnect refrigerant pressure switch connector. Connect jumper wire between terminals of A/C high-pressure switch connector. Connect jumper wires between terminals of refrigerant pressure switch connector. Turn ignition switch to ON position. Access AC_REQ PID using M-MDS. Turn A/C switch on and set blower fan to any speed. Does the PID turn ON and OFF properly?	Yes	Inspect refrigerant pressure switch operation. If switch is okay, 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 1AU Open circuit between blower motor fan switch and resistor (if blower motor does not operate) 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 whether A/C relay is stuck open. Replace if necessary.
4		No	Inspect the following and repair or replace if necessary: Refrigerant charging amount A/C compressor for seizure
5	Verify test results. If okay, 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 idle it. 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 1I If both items okay, 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 okay, inspect magnetic clutch for stuck engagement or clearance.
3	Disconnect refrigerant pressure switch connector. Start engine and turn A/C switch on. NOTE: A/C should not work when disconnecting connector. If A/C remains working, short to GND circuit may be present. Does A/C remain working?	Yes	Inspect for short to GND circuit between refrigerant pressure switch and PCM terminal 1AU
3		No	Go to the next step.
4	Reconnect refrigerant pressure switch connector. Turn off A/C switch. NOTE: A/C should not work when turning A/C switch off. If A/C remains working, short to GND circuit may be present. Does A/C remain working?	Yes	Inspect following: Short to GND circuit between A/C switch and A/C amplifier Short to GND circuit between A/C amplifier and refrigerant pressure switch
4		No	Inspect whether A/C switch is stuck closed.
5	Verify test results. If okay, 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 disconnecting connector. If A/C remains working, short to GND circuit may be present.

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

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 IS ALWAYS ON OR 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.
3	Verify test results. If okay, 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 if necessary. Repeat Step 2.
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	Install fuel pressure gauge between fuel pipe and fuel distributor. Start engine and idle it. Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ).	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 okay, replace fuel pump unit. High: Replace fuel pump unit.
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 okay, suggest trying a different brand since sulfur content can vary in different fuels. If fuel tank vent system is not okay, repair or replace malfunctioning parts.
6	Verify test results. If okay, 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	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 okay, 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	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 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 okay, 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 compression pressure correct? (See COMPRESSION INSPECTION [L3] ).	Yes	Go to the next step.
4		No	Repair or replace malfunctioning parts.
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. Turn ignition switch to ON position (Engine off). Is fuel line pressure correct with ignition switch at ON? Fuel line pressure 375-450 kPa {3.9-4.5 kgf/cm 2 , 55-65 psi}	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 okay, replace fuel pump unit. High: Replace fuel pump unit.
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.
8	Remove suspected fuel injector. Inspect the following: Resistance (See FUEL INJECTOR INSPECTION [L3] ). Fuel injection volume (See FUEL INJECTOR INSPECTION [L3] ). Are all above items normal?	Yes	Inspect for open circuit between suspected fuel injector connector terminal and PCM connector at the following terminals: For #1 cylinder: 2BB For #2 cylinder: 2BC For #3 cylinder: 2BD For #4 cylinder: 2AZ
8		No	Replace fuel injector.
9	Is air cleaner element free of restrictions?	Yes	Go to the next step.
9	Is air cleaner element free of restrictions?	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 parts.
11	Install fuel pressure gauge between fuel filter and fuel distributor. Short check connector terminal F/P to body GND using a jumper wire. Turn ignition switch to ON position (Engine off). Is fuel line pressure correct with ignition switch at ON? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Fuel line pressure 375-450 kPa {3.9-4.5 kgf/cm 2 , 55-65 psi}	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 okay, replace fuel pump unit. High: Replace fuel pump unit.
12	Inspect the following PIDs: ECT O2S11 (When engine can be started) MAF (See PCM INSPECTION [L3] ). Are PIDs normal?	Yes	Go to the next step.
12		No	Repair or replace malfunctioning parts.
13	Perform purge control inspection. (When engine can be started) (See PURGE CONTROL SYSTEM INSPECTION ). Is purge control correct?	Yes	Go to the next step.
13		No	Repair or replace malfunctioning parts.
14	Perform compression inspection. Is compression correct?	Yes	Inspect for clogging in exhaust system.
14	Perform compression inspection. Is compression correct?	No	Repair or replace malfunctioning parts.
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. Turn ignition switch to ON position (Engine off). Is fuel line pressure correct with ignition switch at ON? (See FUEL LINE PRESSURE INSPECTION [L3, AJ] ). Fuel line pressure 375-450 kPa {3.9-4.5 kgf/cm 2 , 55-65 psi}	Yes	Inspect the following PIDs: ECT O2S11 MAF (See PCM INSPECTION [L3] ). Inspect PCM GND condition.
16		No	Zero or low: Inspect fuel pump relay and fuel pump circuit. Inspect for clogged fuel line. If okay, replace fuel pump unit. High: Replace fuel pump unit.
17	Verify test results. If okay, 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

Inspection Method for Sensors

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

Scheme 167

Scheme 167: Inspection Method for Actuators or Relays

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

Intake Manifold Vacuum Inspection

Verify air intake hoses are installed properly.
Start the engine and run it at idle.
Disconnect the vacuum hose between the intake manifold and purge solenoid valve from the intake manifold side.
Connect a vacuum gauge to the intake manifold and measure the intake manifold vacuum. If not as specified, inspect the following: Specification More than 60 kPa {450 mmHg, 18 inHg} NOTE: Air suction can be located by engine speed change when lubricant is sprayed on the area where suction is occurring. Air suction at throttle body, intake manifold and PCV valve installation points EGR valve (stuck open) Fuel injector insulator Engine compression (See «COMPRESSION INSPECTION [L3]»(ref-288763-S03098093032008062500000) ).

Engine coolant temperature compensation inspection

Connect M-MDS to the DLC-2.
Select the following PIDs: ECT IAT RPM
Verify that the engine is cold, then start the engine.
Verify that the engine speed decreases as the engine warms up. If the engine speed does not decrease or decreases slowly, inspect the following: ECT sensor and related harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [L3]»(ref-288753-S09443503532008062500000) ). Electronic throttle body and related harness (See «THROTTLE ACTUATOR INSPECTION [L3]»(ref-288764-S10124867512008062500000) ).

Load compensation inspection

Start the engine and run it at idle.
Connect M-MDS to the DLC-2.
Verify that P0506 or P0507 is not displayed. If P0506, or P0507 is displayed, perform DTC inspection. (See «DTC TABLE [L3]»(ref-288790-S28587536572008062500000) ).
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 load condition is not as specified, 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 [L3]»(ref-288753-S19817046372008062500000) ).

Engine speed

Load condition		Engine speed (RPM) (1)
No load		650-750
E/L operating		650-750
P/S operating		650-750
A/C operating (2)	Refrigerant pressure low (3)	750-850
A/C operating (2)	Refrigerant pressure high (4)	750-850
(1) Neutral or P position (2) A/C switch and fan switch are on. (3) Refrigerant pressure switch (middle pressure) is off. (4) Refrigerant pressure switch (middle pressure) is on.

(1)	Neutral or P position

(2)	A/C switch and fan switch are on.

(3)	Refrigerant pressure switch (middle pressure) is off.

(4)	Refrigerant pressure switch (middle pressure) is on.

ENGINE SPEED SPECIFICATION

Throttle position (TP) sweep inspection

Connect the M-MDS to DLC-2.
Turn the ignition switch to ON position.
Verify that none of the following DTC are displayed: P0122, P0123, P0222, P0223, P0638, P2100*2, P2101, P2102*2, P2103*2, P2107, P2108, P2109*1, P2112*1, P2119, P2122, P2123, P2127, P2128, P2135, P2138 If any one DTC is displayed, perform DTC inspection.
Access TP_REL PID.
Verify that the PID reading is within the CTP value. (See «PCM INSPECTION [L3]»(ref-288753-S39441275972008062500000) ). If the PID reading is out of range, perform the following: Remove the air duct from throttle valve body. Verify that the throttle valve opens when accelerator pedal is depressed. If the throttle valve opens, inspect the throttle position sensor and related harness. If the throttle valve does not open, inspect the throttle actuator control motor and related harness.
Gradually depress the throttle pedal and verify that the PID reading increases lineally. If the PID reading drops momentarily, inspect the following: Throttle position sensor
Fully depress the throttle pedal and verify that the PID reading is within WOT value. (See «PCM INSPECTION [L3]»(ref-288753-S39441275972008062500000) ). If the PID reading is out of range, perform the followings: Remove the air duct from throttle valve body. Verify that the throttle valve opens when throttle pedal is depressed. If the throttle valve opens, inspect the throttle position sensor and related harness. If the throttle valve does not open, inspect the throttle actuator control motor and related harness.

*1 : California emission regulation applicable ATX model

*2 : Except for California emission regulation applicable ATX model

Fuel Cut Control System Inspection

Warm up engine and idle it.
Turn off the electrical loads and A/C switch.
Connect M-MDS to the DLC-2.
Select RPM PID.
Listen for the fuel injector operation sound at all cylinders using the soundscope and monitor both PIDs while performing the following steps: Depress the accelerator pedal and increase the engine speed to 4,000 RPM . Quickly release the accelerator pedal (brake pedal is not depressed) and verify that the fuel injector operation sound stops, and starts again when the engine speed drops below 1,200 RPM . If not as specified, inspect the following: ECT sensor and related harness (See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [L3]»(ref-288753-S09443503532008062500000) ). Neutral/clutch pedal position switch and related harness (MTX) (See «CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [L3]»(ref-288753-S35574057172008062500000) ). TR switch and related harness (ATX) (See «TRANSAXLE RANGE (TR) SWITCH INSPECTION [FS5A-EL]»(ref-288756-S36052939872008062500000) ). (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 1H)

Spark Test

Disconnect the fuel pump relay.
Verify that each ignition coil and connector is connected properly.
Inspect the ignition system in the following procedure. WARNING: High voltage in the ignition system can cause strong electrical shock which can result in serious injury. Avoid direct contact to the vehicle body during the following spark test. DIAGNOSTIC PROCEDURE 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. 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. 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. No Some cylinders do not spark: Go to the next step. All cylinders do not spark: Go to Step 5. 4 Inspect the following wiring harnesses for open or short: Ignition coil No.1 terminal C-PCM terminal 2BA Ignition coil No.2 terminal C-PCM terminal 2AW Ignition coil No.3 terminal C-PCM terminal 2AX Ignition coil No.4 terminal C-PCM terminal 2AT Are the wiring harnesses normal? Yes Inspect and replace the ignition coil. (See «IGNITION COIL INSPECTION [L3, AJ]»(ref-288816-S15104754012008062500000) ). No Repair or replace the malfunctioning part, then go to Step 1. 5 Measure the voltage at terminal A in each ignition coils. Is the voltage B+ ? Yes Go to the next step. No Inspect power supply circuit of ignition coils. 6 Disconnect the ignition switch connectors. Verify that the continuity between ignition coils terminal B and GND. Is there any continuity? Yes Go to the next step. No Inspect GND circuit for of ignition coil. 7 Does the PCM connector or ignition coil connectors have poor connection? Yes Repair or replace the connector, then go to Step 1. No Go to the next step. 8 Are the following parts normal? CKP sensor and crankshaft pulley Yes Inspect for open or short circuit in wiring harness and connector of CKP sensor. No Repair or replace the malfunctioning part, then go to Step 1.

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 [L3]»(ref-288790-S28587536572008062500000) ).
Start the engine and idle it.
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 is increased. If the EGR valve will increase, inspect the following: EGR valve (stuck open or close) Wiring harness and connectors (Main relay-EGR valve-PCM) If the SEGRP value does not increase, inspect the VSS, APP1, APP2, TP_REL and ECT PIDs. (See «PCM INSPECTION [L3]»(ref-288753-S39441275972008062500000) ).
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 2C) Purge solenoid valve
Warm up the engine to the normal operating temperature.
Stop the engine.
Connect M-MDS to the DLC-2 and verify that the DTC P0443 is shown. Perform DTC inspection. (See «DTC TABLE [L3]»(ref-288790-S28587536572008062500000) ).
Turn the ignition switch to ON position.
Select ECT PID.
Verify that the engine coolant temperature is above 60°C {140°F} . If M-MDS indicates below 60°C {140°F} , perform the ECT sensor inspection.
Set the vehicle on the dynamometer or chassis roller. WARNING: When the dynamometer or chassis roller is operating, there is a possibility that the operator may come into contact with or be caught up in the rotating parts, leading to serious injuries or death. When performing work while the dynamometer or chassis roller is operating, be careful not to contact or be caught up in any of the rotating parts.
Drive vehicle at engine speed approx. 2000 RPM for 30 s or more .
Put a finger to the purge solenoid valve and verify that there is no vacuum applied while step 2 . If there is no vacuum, inspect the following: Wiring harness and connector (Main relay - purge solenoid valve - PCM terminal 2C) 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-288783-S01799004362008062500000) ".
Fully open the throttle valve and verify that the A/C compressor magnetic clutch does not actuate for 2-5 s . If it actuates, inspect as follows: A/C relay Open or short to GND circuit in wiring harness and connectors (Ignition switch-A/C relay-PCM terminal 1I) 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 the 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-MDSin the KOEO (Key On Engine Off) condition instead of actually driving the vehicle.

Scheme 168

Scheme 168: EVAP system test description

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

Scheme 169

Scheme 169: EVAP system malfunction judgment

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

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

DTC CONDITION

Evaporative system test procedure

Select the EVAP system test from the Tool box on the M-MDSdisplay 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 170

Scheme 170: EVAP system leak inspection using leak tester

Scheme 171

Perform the following SST (EVAP System Tester 134-01049) self-test: NOTE: If the tester does not work correctly during the self-test, refer to the tester operator's manual for more detailed self-test procedure. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve. Connect the vehicle interface hose (part of the SST ) to the SELF TEST port located on the control panel. Hand tighten the fitting. (Do not overtighten). Turn the control valve to the TEST position. The gauge should read 331-381 mm {13-15 in} of water. If the gauge is not reading in this range, adjust the pressure by turning the black knob on the low pressure regulator at the nitrogen bottle. Turn the control valve to the HOLD position. Verify that the gauge holds pressure and that the flow meter reads no flow. If there is no drop in pressure and no flow, the tester passes the self-test. If the gauge leaks down, refer to the tester operator's manual.
Connect the SST to the vehicle. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve. Remove the fuel-filler cap from the vehicle. If the fuel-filler cap is not a MAZDA part or equivalent, replace it. Connect the receiver assembly ( SST : 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 change-over valve (COV) in the EVAP system leak detection pump. NOTE: The COV is closed for 10 min unless the following any actions are done: The engine is started. The ignition switch is turned off position.
Make sure the control valve on the 134-01049 is in the HOLD position and that the valve on the cylinder of nitrogen gas is open.
Turn the control valve to the open position and let the system fill. You should note a drop in the gauge pressure along with the flow meter being pegged at maximum flow for several minutes depending on how full or empty the fuel tank is, and how long it takes to completely fill and pressurize the evaporative emissions system hoses.
If the gauge and the flow meter do not settle to a measurable level after 2-3 min , then 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 preset 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 (L3): Diagnosis Mazda 6 GH

SYMPTOM DIAGNOSTIC INDEX [L3]

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Diagnostic procedure

Inspection Method for Sensors

Scheme 167

Intake Manifold Vacuum Inspection

Engine coolant temperature compensation inspection

Load compensation inspection

Throttle position (TP) sweep inspection

Fuel Cut Control System Inspection

Fuel Pump Control System Inspection

Spark Test

EGR Control System Inspection

Purge Control System Inspection

A/C Cut-off Control System Inspection

Evaporative Emission (EVAP) System Leak Inspection

EVAP system leak inspection using the M-MDS

Scheme 168

Scheme 169

Evaporative system test procedure

Scheme 170

Scheme 171

More articles — Symptom Troubleshooting - Engine Control System (L3)

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