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Engine Controls - Tests W/codes - Testing - 2.4: Other Nissan Altima L30

Testing & Diagnostics 34 illustrations ~10664 words

Procedure "A"

  1. Turn ignition off. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect MAF sensor harness connector and turn ignition on. (Scheme 9) Using DVOM, measure voltage between MAF sensor harness connector terminal No. 3 and ground. (Scheme 10) If battery voltage is present, go to next step. If battery voltage is not present, check and repair wiring harness between ECCS relay, PCM and MAF sensor. See WIRING DIAGRAMS article.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 48 and MAF sensor harness connector terminal No. 2. see scheme 2and (Scheme 10). If continuity exists, go to next step. If continuity does not exist, check and repair open in appropriate Black/Red wire between PCM and MAF sensor.
  3. Check continuity between PCM harness connector terminal No. 47 and MAF sensor harness connector terminal No. 1. If continuity exists, go to next step. If continuity does not exist, repair open in appropriate Black/Red wire between PCM and MAF sensor.
  4. Reconnect all connectors. Start engine and warm engine to operating temperature. Pull rubber protector away from MAF sensor connector so terminals can be backprobed. At MAF sensor connector, measure voltage between connector terminal No. 1 (Black/Red wire) and ground. See «MAF SENSOR VOLTAGE TEST»(ref-18071-S13381363572000122900000) table.
  5. If voltage is as specified, check PCM connector for damage or corrosion. If voltage is not as specified, check for dust or foreign material in hot wire air passage of MAF sensor. If air passage is okay, replace MAF sensor.
ApplicationVolts With KOEO (2)Volts At Idle
AltimaLess Than 1.01.2-1.5
(1) Engine speed between idle and 4000 RPM; 1.2-2.7 volts. (2) Key On, Engine Off.
(1)Engine speed between idle and 4000 RPM; 1.2-2.7 volts.
(2)Key On, Engine Off.

MAF SENSOR VOLTAGE TEST (1)

Procedure "B"

  1. Check air duct, vacuum hoses and intake air passage between air duct to collector for disconnected parts or leaks. Reconnect or repair as necessary. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect MAF sensor harness connector. (Scheme 9) Turn ignition on. Using DVOM, measure voltage between MAF sensor harness connector terminal No. 3 and ground. (Scheme 10) If battery voltage is present, go to next step. If battery voltage is not present, check and repair open or short White/Red wire between ECCS relay, PCM and MAF sensor.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 48 and MAF sensor harness connector terminal No. 2. see scheme 2and (Scheme 10). If continuity exists, go to next step. If continuity does not exist, check and repair open in appropriate Black/Red wire between PCM and MAF sensor.
  3. Check continuity between PCM harness connector terminal No. 47 and MAF sensor harness connector terminal No. 1. If continuity exists, go to next step. If continuity does not exist, repair open in appropriate Black/Red wire between PCM and MAF sensor.
  4. Reconnect all connectors. Start engine and warm to operating temperature. Pull rubber protector away from MAF sensor connector so terminals can be backprobed. At MAF sensor connector, measure voltage between connector terminal No. 1 (Black/Red wire) and ground. See «MAF SENSOR VOLTAGE TEST»(ref-18071-S13381363572000122900000) table.
  5. If voltage is as specified, check PCM connector for damage or corrosion. If voltage is not as specified, check for dust or foreign material in hot wire air passage of MAF sensor. If air passage is okay, replace MAF sensor.

Scheme 9

Scheme 9
Scheme 9

Scheme 10

Scheme 10
Scheme 10
  1. Turn ignition off. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect AP sensor harness connector. Ensure water does not exist around AP sensor connector. Turn ignition on. Using DVOM, measure voltage between AP sensor harness connector Red wire and ground. If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, check and repair open or short Red wire between PCM and AP sensor.
  2. Turn ignition off. Using DVOM, check continuity between AP sensor harness connector Black wire and ground. If continuity exists, go to next step. If continuity does not exist, repair open or short in Black wire between PCM, TCM and AP sensor.
  3. Disconnect PCM harness connector. Check continuity between PCM harness connector terminal No. 66 and AP sensor harness connector White wire. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open or short in White wire between PCM and AP sensor.
  4. Reconnect all connectors. Start engine and warm to operating temperature. Turn ignition off. Pull rubber protector away from AP sensor connector so terminals can be backprobed. Turn ignition on. At AP sensor connector, measure and record voltage between connector White wire and ground.
  5. Voltage should be 3.2-4.8 volts. Disconnect vacuum line to AP sensor. Using a vacuum pump, apply 7.87 in. Hg of vacuum to AP sensor. Voltage should now be 1.0-1.4 volts less than previously measured. If voltage is not as specified, replace AP sensor. If voltage is as specified, check and repair PCM connector for damage or corrosion and retest system.
  1. Start engine and warm to operating temperature. Turn ignition off. Connect a vacuum gauge with a vacuum "T" in between MAP/BARO solenoid and AP sensor. Turn ignition on.
  2. Vacuum should not be indicated on gauge with engine stopped. Start engine and ensure vacuum is indicated on gauge. If vacuum exists, go to next step. If vacuum does not exist, check and repair vacuum hoses, vacuum port (clogged) or intake system (leaks).
  3. Start engine and warm to operating temperature. Turn ignition off. Pull rubber protector away from AP sensor connector so terminals can be backprobed. Turn ignition on. At AP sensor connector, measure and record voltage between connector White wire and ground.
  4. Voltage should be 3.2-4.8 volts. Disconnect vacuum line to AP sensor. Using a vacuum pump, apply 7.87 in. Hg of vacuum to AP sensor. Voltage should now be 1.0-1.4 volts less than previously measured. If voltage is as specified, go to next step. If voltage is not as specified, replace AP sensor.
  5. Check MAP/BARO solenoid. See «DTC P1105»(ref-18071-S04700628572000122900000) MANIFOLD ABSOLUTE PRESSURE (MAP)/BAROMETRIC PRESSURE (BARO) SOLENOID. If MAP/BARO solenoid is bad, replace solenoid and retest system. If MAP/BARO solenoid is okay, check and repair PCM connector for damage or corrosion and retest system.

Procedure

  1. Turn ignition off. Disconnect IAT sensor harness connector. (Scheme 11) Using DVOM, measure voltage between IAT sensor harness connector Red/Yellow wire and ground. If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, repair open or short in Red/Yellow wire between PCM and IAT sensor.
  2. Turn ignition off. Using DVOM, check continuity between IAT sensor harness connector Black wire and ground. If continuity exists, go to next step. If continuity does not exists, repair open in Black wire between PCM, TCM and IAT sensor.
  3. Leave IAT sensor disconnected. Measure resistance between IAT sensor terminals. See INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE table. If resistance is not as specified, replace IAT sensor. If resistance is as specified, check system connectors for damage or corrosion and retest.
Temperature - °F (°C)Ohms
68 (20)2100-2900
176 (80)300-330

INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE

Scheme 11

Scheme 11
Scheme 11
  1. Turn ignition off. Disconnect ECT sensor harness connector. (Scheme 12) Turn ignition on. Using DVOM, measure voltage between ECT sensor harness connector Brown/Yellow wire and ground. If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, repair open or short in Brown/Yellow wire between PCM and ECT sensor.
  2. Turn ignition off. Using DVOM, check continuity between ECT sensor harness connector Black wire and ground. If continuity exists, go to next step. If continuity does not exist, repair open Black wire between PCM, TCM and ECT sensor.
  3. Leave ECT sensor disconnected. Measure resistance between ECT sensor terminals. See ENGINE COOLANT TEMPERATURE (ECT) SENSOR RESISTANCE table. If resistance is not as specified, replace ECT sensor. If resistance is as specified, check thermostat for correct operation. If thermostat operation is okay, check PCM connector for damage or corrosion. Repair or replace as necessary.
Temperature - °F (°C)Ohms
68 (20)2100-2900
122 (50)680-1000
194 (90)236-260

ENGINE COOLANT TEMPERATURE (ECT) SENSOR RESISTANCE

Scheme 12

Scheme 12
Scheme 12
  1. Turn ignition off. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect TP sensor harness connector. (Scheme 13) Turn ignition on. Using DVOM, measure voltage between TP sensor harness connector Red wire and ground. If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, repair open or short in Red wire between PCM and TP sensor.
  2. Turn ignition off. Using DVOM, check continuity between TP sensor harness connector Black wire and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between PCM, TCM and TP sensor.
  3. Disconnect PCM harness connector. Using DVOM, check continuity between PCM harness connector terminal No. 23 and TP sensor harness connector Yellow wire. If continuity exists, go to next step. If continuity does not exist, repair open or short in Yellow wire between PCM and TP sensor.
  4. Leave TP sensor harness connector disconnected. While opening and closing throttle, measure resistance between TP sensor Yellow wire terminal and Black wire terminal. See THROTTLE POSITION (TP) SENSOR RESISTANCE TEST table. If resistance is as specified, check wiring harness for damaged pins or corrosion. If no faults are found, adjust TP sensor. See ADJUSTMENTS article. If resistance is still not as specified after adjustment, replace TP sensor.
Throttle PositionOhms
Fully Closed(1) 500
Partially Opened500-4000
Fully Open(1) 4000
(1) Approximate resistance.
(1)Approximate resistance.

THROTTLE POSITION (TP) SENSOR RESISTANCE TEST

Scheme 13

Scheme 13
Scheme 13
  1. Turn ignition off. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect TP sensor harness connector. (Scheme 13) Turn ignition on. Using DVOM, measure voltage between TP sensor harness connector Red wire and ground. If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, repair open or short in Red wire between PCM and TP sensor.
  2. Turn ignition off. Using DVOM, check continuity between TP sensor harness connector Black wire and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between PCM, TCM and TP sensor.
  3. Disconnect PCM harness connector. Using DVOM, check continuity between PCM harness connector terminal No. 23 and TP sensor harness connector Yellow wire. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open or short in Yellow wire between PCM and TP sensor.
  4. Leave TP sensor disconnected. While opening and closing throttle, measure resistance between TP sensor Yellow wire terminal and Black wire terminal. See «THROTTLE POSITION (TP) SENSOR RESISTANCE TEST»(ref-18071-S17163918632000122900000) table. If resistance is as specified, go to next step. If no faults are found, adjust TP sensor. See ADJUSTMENTS article. If resistance is still not as specified after adjustment, replace TP sensor.
  5. Check the following components for malfunction: Mass Airflow (MAF) sensor, Camshaft Position (CMP) sensor and fuel injectors. See SYSTEM/COMPONENT TESTS article for testing procedures. Replace as necessary and retest system.

Procedure "C"

  1. Check TP sensor adjustment and adjust as necessary. See ADJUSTMENTS article. Check air duct, vacuum hoses and intake air passage between air duct to collector for disconnected parts or leaks. Reconnect or repair as necessary.
  2. Turn ignition off. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect TP sensor harness connector. (Scheme 13) Turn ignition on. Using DVOM, measure voltage between TP sensor harness connector Red wire and ground. If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, repair open or short in Red wire between PCM and TP sensor.
  3. Turn ignition off. Using DVOM, check continuity between TP sensor harness connector Black wire and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between PCM, TCM and TP sensor.
  4. Disconnect PCM harness connector. Using DVOM, check continuity between PCM harness connector terminal No. 23 and TP sensor harness connector Yellow wire. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open or short in Yellow wire between PCM and TP sensor.
  5. Leave TP sensor disconnected. While opening and closing throttle, measure resistance between TP sensor Yellow wire terminal and Black wire terminal. See «THROTTLE POSITION (TP) SENSOR RESISTANCE TEST»(ref-18071-S17163918632000122900000) table. If resistance is as specified, check wiring harness for damaged pins or corrosion. If resistance is not as specified, replace TP sensor.
  1. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Start engine and run at idle. Check for leaks in exhaust system before three way catalyst. Check for leaks in intake system after Mass Airflow (MAF) sensor. Repair or replace faulty components as required. If no leaks are detected, go to next step.
  2. Start engine and warm to operating temperature. Turn ignition off. Disconnect MAF sensor harness connector. (Scheme 9) Start engine and run for at least 3 seconds at idle speed. Turn ignition off and reconnect MAF sensor harness connector. Turn ignition on and ensure DTC P0100 is set. Erase all codes. Start engine and let idle for at least 10 minutes. Recheck codes. If DTC P0171 or P0172 is set and vehicle is difficult to start, diagnose those codes first. See «DTC P0171 OR P0172: FUEL INJECTION SYSTEM FUNCTION»(ref-18071-S10943909872000122900000). If DTCs P0171 or P0172 are not detected and it is not difficult to start engine, go to next step.
  3. Turn ignition off. Disconnect front HO2S and PCM harness connectors. see scheme 1and (Scheme 14). Using DVOM, check continuity between PCM harness connector terminal No. 46 and HO2S harness connector White wire. see scheme 2 If continuity does not exist, repair open White wire. If continuity exists, check continuity between PCM terminal No. 46 (White wire) and ground. If continuity exists, repair short in White wire. If continuity does not exist, go to next step.
  4. Turn ignition off. Disconnect front HO2S harness connector. Measure resistance between outer terminals. Resistance should be 2.3-4.3 ohms at 77°F (25°C). Check continuity between both outer terminals and center terminal. Continuity should not exist. Replace HO2S if not as specified. If HO2S is okay, go to next step.
  5. Check MAF sensor and PCV valve. Replace as necessary. Disconnect PCM and HO2S harness connectors. Check terminals for damage or corrosion. Repair as necessary. If fault is still present, replace front HO2S sensor.

Scheme 14

Scheme 14
Scheme 14
  1. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Start engine and check exhaust and intake systems for leaks. Repair as necessary.
  2. Start engine and warm to operating temperature. Turn ignition off. Disconnect MAF sensor harness connector. (Scheme 9) Start engine and run for at least 3 seconds at idle speed. Turn ignition off and reconnect MAF sensor harness connector. Turn ignition on and ensure DTC P0100 is set. Erase all codes. Start engine and let idle for at least 10 minutes. Recheck codes. If DTC P0171 or P0172 is set and vehicle is difficult to start, diagnose those codes first. See «DTC P0171 OR P0172: FUEL INJECTION SYSTEM FUNCTION»(ref-18071-S10943909872000122900000). If DTCs P0171 or P0172 are not detected and it is not difficult to start engine, go to next step.
  3. Turn ignition off. Disconnect front HO2S harness connector. Measure resistance between outer terminals. Resistance should be 2.3-4.3 ohms at 77°F (25°C). Check continuity between both HO2S connector outer terminals and center terminal. Continuity should not exist. Replace HO2S if not as specified. If HO2S is okay, go to next step.
  4. Disconnect PCM and HO2S harness connectors. Check terminals for damage or corrosion. Repair as necessary. If fault is still present, replace front HO2S sensor.
  1. Turn ignition off. Disconnect front HO2S harness connector Turn ignition on. (Scheme 14) Using DVOM, measure voltage between front HO2S harness connector terminal No. 3 (Light Green/Black wire) and ground. (Scheme 15) If battery voltage is not present, check for blown fuse or repair open or short in Light Green/Black wire as required. If battery voltage is present, go to next step.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 115 and HO2S harness connector terminal No. 1 (Orange wire). see scheme 2and (Scheme 15). If continuity does not exist, repair open in Orange wire. If continuity exists, go to next step.
  3. Turn ignition off. Leave front HO2S harness connector disconnected. Measure resistance between outer terminals. Resistance should be 2.3-4.3 ohms at 77°F (25°C). Check continuity between both outer terminals and center terminal. Continuity should not be present. Replace HO2S if resistance is not as specified. If HO2S is okay, go to next step.
  4. Check PCM and HO2S harness connector terminals for damage or corrosion. Repair as necessary. If fault is still present, replace front HO2S sensor.

Scheme 15

Scheme 15
Scheme 15
  1. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Start engine and warm to operating temperature. Turn ignition off. Disconnect MAF sensor harness connector. (Scheme 9) Start engine and run for at least 3 seconds at idle speed. Turn ignition off and reconnect MAF sensor harness connector.
  2. Turn ignition on and ensure DTC P0100 is set. Erase all codes. Start engine and let idle for at least 10 minutes. Recheck codes. If DTC P0171 or P0172 is set and vehicle is difficult to start, diagnose those codes first. See «DTC P0171 OR P0172: FUEL INJECTION SYSTEM FUNCTION»(ref-18071-S10943909872000122900000). If DTCs P0171 or P0172 are not detected and it is not difficult to start engine, go to next step.
  3. Turn ignition off. Disconnect rear HO2S and PCM connectors. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 46 and HO2S harness connector terminal No. 1 (White wire). see scheme 2and (Scheme 16). If continuity does not exist, repair open White wire. If continuity exists, check continuity between PCM terminal No. 46 (White wire) and ground. If continuity exists, repair short in White wire. If continuity does not exist, go to next step.
  4. Check continuity between rear HO2S harness connector terminal No. 4 (Black wire) and ground. If continuity exists, go to next step. If continuity does not exist, repair open Black wire between PCM, HO2S and ground.
  5. Reconnect all connectors. Start engine and warm to normal operating temperature. Turn ignition off. Connect DVOM positive lead to PCM harness connector terminal No. 52. Connect DVOM negative lead to PCM harness connector terminal No. 43.
  6. While monitoring DVOM, restart engine and steadily increase engine speed to 4000 RPM and release. Repeat at least 10 times. If voltage does not rise more than.48 volt at least one time, go to next step. If voltage rises more than.48 volt at least one time, rear HO2S is okay. Check wiring harness and connectors for poor connection and damaged or corroded terminals. Repair as necessary.
  7. Idle engine for 10 minutes and recheck voltage. If voltage does not fall less than.43 volt at least once, replace rear HO2S and retest system. If voltage drops less than.43 volt at least once, rear HO2S is okay. Check wiring harness and connectors for poor connection and damaged or corroded terminals. Repair as necessary.

Scheme 16

Scheme 16
Scheme 16
  1. Disconnect rear HO2S harness connector. Turn ignition on. Using DVOM, measure voltage between rear HO2S harness connector terminal No. 2 (Brown/Yellow wire) and ground. (Scheme 16) If battery voltage is present, go to next step. If battery voltage is not present, check for open or short in Brown/Yellow wire. Repair as required.
  2. Turn ignition off. Disconnect PCM harness connector. Using DVOM, check continuity between rear HO2S harness connector terminal No. 3 (Red/Yellow wire) and PCM harness connector terminal No. 110. see scheme 2and (Scheme 16). If continuity exists, go to next step. If continuity does not exist, repair open in Red/Yellow wire between PCM and rear HO2S.
  3. Leave rear HO2S harness connector disconnected. Measure resistance between HO2S terminals No. 2 (Brown/Yellow wire) and No. 3 (Red/Yellow wire). Resistance should be 2.3-4.3 ohms at 77°F (25°C). Check continuity between both outer terminals and center terminal. Continuity should not be present. Replace HO2S if not as specified. If HO2S is okay, go to next step.
  4. Check PCM and HO2S harness connector terminals for damage or corrosion. Repair as necessary. If fault is still present, replace rear HO2S sensor.
  1. Start engine and run at idle. Check for leaks in exhaust system before three way catalyst. Check for leaks in intake system after MAF sensor. Repair or replace faulty components as required. If no leaks are detected, go to next step.
  2. Turn ignition off. Disconnect front HO2S and PCM harness connectors. see scheme 1and (Scheme 14). Using DVOM, check continuity between PCM harness connector terminal No. 46 and front HO2S harness connector terminal No. 2 (White wire). see scheme 2and (Scheme 15). Continuity should exist. check Continuity between PCM terminal No. 46 (White wire) and ground. Continuity should not exist. If continuity is as specified, go to next step. If continuity is not as specified, repair fault in White wire between PCM, HO2S and ground.
  3. Turn ignition off. Relieve fuel pressure. See REMOVE/INSTALL/OVERHAUL article. Install fuel pressure gauge. With ignition on, fuel pressure should be about 43 psi (3.0 kg/cm 2 ). At idle, fuel pressure should be about 34 psi (2.4 kg/cm 2 ). If fuel pressure is not as specified, check for fault in fuel pump and related circuits. See FUEL SYSTEM in SYSTEM/COMPONENT TESTS article. If fuel pressure is okay, inspect MAF sensor. See «DTC P0100: MASS AIRFLOW (MAF) SENSOR»(ref-18071-S34762042582000122900000). If MAF sensor is okay, go to next step.
  4. With engine idling, listen to each injector and ensure each one is clicking. Turn ignition off and remove injector assembly. Keep all associated fuel lines connected. Place a suitable cup under each injector to collect fuel. Disconnect ignition coil harness connectors. Turn ignition on. Verify fuel is not dripping from injectors. Replace injectors which are leaking. Crank engine for 3 seconds and ensure each injector sprays fuel. If injectors are okay, check PCM pins and terminals for damage or corrosion and repair as necessary.
  1. Disconnect TFT sensor harness connector. Turn ignition on. Using DVOM, measure voltage between TFT harness connector terminal "T" (Light Green/Red wire) and ground. (Scheme 17) If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, repair open or short in Light Green/Red wire between PCM and TFT sensor.
  2. Turn ignition off. Using DVOM, check continuity between TFT harness connector terminal "E" (Black wire) and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between TFT sensor and ground.
  3. Leave TFT sensor disconnected. Measure resistance between sensor connector terminals "T" and "E". See «TANK FUEL TEMPERATURE (TFT) SENSOR RESISTANCE»(ref-18071-S14132563992000122900000) table. If resistance is not as specified, replace TFT sensor. See REMOVE/INSTALL/OVERHAUL article. If resistance is as specified, check PCM connector for damage or corrosion.
Temperature - °F (°C)Ohms
68 (20)2300-2700
122 (50)790-900

TANK FUEL TEMPERATURE (TFT) SENSOR RESISTANCE

Scheme 17

Scheme 17
Scheme 17
  1. Start engine and run at idle. Check for intake air leaks. If a leak is detected, repair as necessary. Stop engine and visually inspect exhaust system, three way catalyst and muffler for damage. Repair as necessary. If no problems are detected, go to next step.
  2. Ensure EGR operation is normal. See «DTC P0400: EGR FUNCTION»(ref-18071-S33339687532000122900000) . Repair as necessary. If no faults are detected, perform power balance test. Start engine and allow to idle. Individually, disconnect fuel injector connectors. If engine speed momentarily drops, go to step 4). If engine speed does not momentarily drop, check appropriate fuel injector. See FUEL SYSTEM in SYSTEM/COMPONENT TESTS article. Injector should be rapidly clicking at engine idle speed. If no sound is detected, check injector harness for open or short conditions, check injector for proper operation. If no faults are detected, go to next step.
  3. Disconnect ignition wire from spark plug. Connect a known good spark plug. Place end of spark plug against a suitable ground and crank engine. If no spark is detected, check ignition wires for defects and repair as necessary. Check ignition coil, power transistor and related circuits. See «DTC P1320: IGNITION SIGNAL»(ref-18071-S15333028822000122900000) . If spark is detected, go to next step.
  4. Remove spark plugs. Inspect for proper gap, fouling or damage. Replace spark plugs as necessary. Check cylinder compression. See SPECIFICATIONS article. If compression is not within specifications, check pistons, rings, valves. Check fuel pressure. If pressure is not within specifications, check fuel pump and related circuits. Check ignition timing and adjust as necessary. Check front HO2S sensor. See «DTC P0130, P0133, P0134: FRONT HEATED OXYGEN SENSOR»(ref-18071-S21423455852000122900000) (HO2S). Check MAF sensor. See «DTC P0100: MASS AIRFLOW (MAF) SENSOR»(ref-18071-S34762042582000122900000) .
  5. Inspect ignition wires for cracks, damage, burned terminals and improper fit. See IGNITION CHECKS in BASIC TESTING article. Repair or replace as necessary. If no faults are found, go to next step.
  6. Inspect PCM pin terminals for damage or corrosion, and repair as necessary. Connect PCM and retest vehicle. Check to see if DTC is still present. If DTC is still present, repeat step 1).
  1. Disconnect PCM harness connector. see scheme 1 Using DVOM, measure resistance PCM harness connector terminal No. 54 and ground. see scheme 2 Resistance should be 500-620 k/ohms. If resistance is as specified, go to next step. If resistance is not as specified, repair open or short in White wire between PCM and knock sensor. If wiring harness is okay, replace knock sensor. 2) Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect engine harness No. 2 connector. (Scheme 18) Using DVOM, check continuity between engine harness No. 2 connector terminal No. 2 (White wire) and ground. If continuity does not exist, repair open in White wire. If continuity exists, check PCM pin terminals and engine harness No. 2 connector for damage or corrosion. Repair as necessary.

Scheme 18

Scheme 18
Scheme 18
  1. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect PCM and CKP sensor harness connectors. see scheme 1and (Scheme 19). Using DVOM, check continuity between PCM harness connector terminal No. 53 and CKP sensor harness connector terminal No. 1 (Brown wire). see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open or short in Brown wire between PCM connector.
  2. Reconnect PCM harness connector. Using DVOM, check continuity between CKP sensor harness connector terminal No. 2 (Black/Red wire) and ground. If continuity exists, go to next step. If continuity does not exist, repair open or short in Black/Red wire between PCM and CKP sensor connectors.
  3. Verify flywheel gear teeth are not damaged. If chipping or damage is observed, replace flywheel or drive plate. Disconnect and remove CKP sensor by loosening sensor fixing bolt. With ambient temperature about 77°F (25°C), measure resistance between CKP sensor terminals. Resistance should be 432-528 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace CKP sensor.
  4. Disconnect PCM harness connector. Check connector pins for damage or corrosion. Check all circuit connectors for clean, tight fit and repair as necessary. If fault is still present, replace CKP sensor.

Scheme 19

Scheme 19
Scheme 19
  1. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect CMP sensor connector. (Scheme 20) Turn ignition on. Using a voltmeter, measure voltage between CMP sensor harness connector terminal No. 5 (White/Red wire) and ground. (Scheme 21) If battery voltage is present, go to next step. If battery voltage is not present, repair open or short in White/Red wire between ECCS relay and CMP sensor.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 41 and CMP sensor harness connector terminal No. 4 (Black/White wire). see scheme 2and (Scheme 21). Check continuity between PCM connector terminals No. 40, 44 and CMP sensor connector terminal No. 3 (Blue and Blue/Yellow wire). Continuity should exist between each measurement. If continuity is as specified, go to next step. If continuity is not as specified, repair open or short in appropriate wire between PCM and CMP sensor.
  3. Using DVOM, check continuity between CMP sensor harness connector terminal No. 6 (Black wire) and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between CMP sensor and ground.
  4. Reconnect all connectors. Start engine, warm to operating temperature and let engine idle. Set DVOM on AC scale. Using DVOM to backprobe CMP harness connector, measure and record voltage between terminal No. 3 (Blue wire) and ground. (Scheme 21) Measure and record voltage between CMP sensor connector terminal No. 4 (Black/White wire) and ground. Accelerate engine speed to 2000 RPM and measure voltages again. Voltage should be as specified. See «CAMSHAFT POSITION (CMP) SENSOR VOLTAGE SPECIFICATIONS»(ref-18071-S33936896182000122900000) table. If voltage is as specified, go to next step. If voltages are not as specified, replace distributor assembly and retest system.
  5. Disconnect PCM harness connector. Check connector pins for damage or corrosion. Check all circuit connectors for clean, tight fit and repair as necessary. If fault is still present, replace CMP sensor.
Measured Between Terminal No. & GroundVoltage
Idling
32.5
4.1-.5
2000 RPM
32.3-2.5
4.2-.4

CAMSHAFT POSITION (CMP) SENSOR VOLTAGE SPECIFICATIONS

Scheme 20

Scheme 20
Scheme 20

Scheme 21

Scheme 21
Scheme 21
  1. Check exhaust system for leaks. Start engine and warm to operating temperature. Raise and support vehicle so drive wheels are off the ground. Set engine speed between 2000-4000 RPM with transmission in "1" position. Disconnect vacuum hose to EGR valve. (Scheme 22) If vacuum exists, check EGR valve for proper operation. See SYSTEM/COMPONENT TESTS article. If vacuum does not exist, inspect and repair vacuum hose for clogging, cracks or improper connection. If hoses are okay, go to next step.
  2. Turn ignition off and wait for at least 5 seconds. Turn ignition on. Start engine and accelerate to 2000 RPM with transmission in "1" position. While disconnecting and reconnecting EGR valve solenoid harness connector, listen for clicking sound of solenoid operating. If solenoid is okay, go to next step. If solenoid is not okay, replace EGR valve solenoid and retest system.
  3. Inspect EGR valve and EVAP canister purge control solenoid valve. See SYSTEM/COMPONENT TESTS article. Repair or replace EGR valve and/or EVAP canister purge control solenoid valve as required. If no faults are found, go to next step.
  4. Inspect EVAP canister and canister purge control solenoid. Check vacuum hose into EVAP canister for clogging, cracks or improper connection. Repair or replace as required. If no faults are found, go to next step.
  5. Inspect EGRC-BPT valve. See «DTC P0402: EGR CONTROL BACKPRESSURE TRANSDUCER (EGRC-BPT) VALVE»(ref-18071-S22873190802000122900000). Replace EGRC-BPT valve as required. If EGRC-BPT valve is okay, disconnect and reconnect harness connectors. Check all circuit connectors for clean, tight fit and repair as necessary.

Scheme 22

Scheme 22
Scheme 22

Ensure vacuum system hoses are routed correctly. (Scheme 23) Check vacuum lines for clogging, cracks or improper connection. Check CMP sensor, MAF sensor, EGR solenoid valve, EGR valve, EGRC-BPT valve and EGR system. See SYSTEM/COMPONENT TESTS article. Repair or replace as required and retest system.

Scheme 23

Scheme 23: Procedure
Scheme 23: Procedure
  1. Inspect exhaust system for damage and repair as necessary. Start engine and run at idle. Check for exhaust leak before three way catalyst. Check for intake air leak after MAF sensor. Repair or replace faulty components as required. If no leaks are detected, go to next step.
  2. Turn ignition on. Using DVOM, check for battery voltage between PCM terminals No. 102 (Red/Black wire), No. 104 (Green/Black wire), No. 107 (Yellow/Black wire) and No. 109 (Blue/Black wire) and ground. see scheme 2 If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short in appropriate wire(s) as required.
  3. Disconnect ignition wires from spark plugs individually and connect a known good spark plug to wire. Place spark plug on good ground. Crank engine and check for spark. If spark exists at every plug wire, go to next step. If spark does not exist, check and repair spark plug wires, ignition coil and power transistor. See SYSTEM/COMPONENT TESTS.
  4. Turn ignition off. Remove injector assembly. Keep all associated fuel lines connected. Disconnect CMP sensor harness connector. Turn ignition on. Verify fuel is not dripping from injectors. Replace injectors which are leaking. If no injectors are faulty, go to next step.
  5. Check ignition timing and adjust as necessary. See ADJUSTMENTS article. Check PCM pins and terminals for damage and check connection of PCM harness connector. Reconnect PCM harness connector and retest. If DTC resets, replace three way catalyst.
  1. Verify fuel filler cap closes properly and does not contain any foreign matter. Verify fuel filler cap is original equipment. Check fuel filler cap vacuum relief valve (inside cap). Wipe valve housing clean. Apply vacuum through cap. There should be a slight resistance, accompanied by valve clicks, indicating valve is okay. Blow air on fuel tank side. Air should pass freely through valve. If valve is clogged or no resistance is felt replace cap assembly. If cap tests okay, go to next step.
  2. Disconnect EVAP canister purge volume control solenoid valve harness connector and vacuum lines. (Scheme 24) Connect fused battery voltage to EVAP canister purge volume control solenoid valve terminals. (Scheme 25) Air should only pass through "A" and "B" ports with battery voltage applied. If operation is as specified, go to next step. If operation is not as specified, replace EVAP canister purge volume control solenoid valve and retest system.
  3. Disconnect EVAP canister vent control valve harness connector. (Scheme 26) Connect fused battery positive voltage to EVAP canister vent control valve terminal No. 1 and battery negative to terminal No. 2. (Scheme 27) Verify there is no air passage continuity from "A" to "B" ports. Disconnect battery and verify there is air passage continuity from "A" to "B" ports. If airflow is as specified, go to next step. If airflow is not as specified, replace control valve and retest system.
  4. Remove EVAP canister with EVAP canister vent control valve attached. See VACUUM DIAGRAMS article for canister location. Turn EVAP canister over and check for water leaking from EVAP canister vent control valve. If water is not leaking from valve, go to next step. If water is leaking from valve, weigh EVAP canister with valve attached. If canister is less than 4.0 lbs. (1.8 kg), go to next step. If canister is equal to or more than 4.0 lbs. (1.8 kg), replace EVAP canister and retest system.
  5. Ensure engine is warmed to operating temperature. Turn ignition off. Raise and support drive wheels. Disconnect EVAP canister purge control solenoid vacuum hose. Start engine and raise engine speed to 2000 RPM. If vacuum is present at vacuum hose, go to next step. If vacuum is not present, check vacuum lines for disconnection or clogging.
  6. Check AP sensor. See «DTC P0105»(ref-18071-S08617428522000122900000) ABSOLUTE PRESSURE (AP) SENSOR. If sensor tests okay, check MAP/BARO switch solenoid. See «DTC P1105»(ref-18071-S04700628572000122900000) MANIFOLD ABSOLUTE PRESSURE (MAP)/BAROMETRIC PRESSURE (BARO) SOLENOID. If solenoid tests okay, check TFT sensor. See «DTC P0180: TANK FUEL TEMPERATURE (TFT) SENSOR»(ref-18071-S19254623432000122900000). If sensor tests okay, check EVAP control system pressure sensor. See «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR»(ref-18071-S13972897472000122900000). If sensor tests okay, go to next step. If any sensor or switch does not test okay, replace as necessary and retest system.
  7. Check EVAP purge line for cracks. Inspect EVAP system components for damage or poor connections. Check refueling control valve. See I - SYSTEM & COMPONENT TESTS article. Disconnect and reconnect harness connectors in circuit. Check PCM connector for damage or corrosion. Repair as necessary.

Scheme 24

Scheme 24
Scheme 24

Scheme 25

Scheme 25
Scheme 25

Scheme 26

Scheme 26
Scheme 26

Scheme 27

Scheme 27
Scheme 27
  1. With ignition off, disconnect EVAP canister purge volume control solenoid valve harness connector. (Scheme 24) Measure voltage between EVAP canister purge volume control solenoid harness connector No. 2 (White/Red wire) and ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open or short in White/Red wire between ECCS relay and EVAP canister purge volume control solenoid valve.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between EVAP canister purge volume control solenoid valve harness connector No. 1 (Blue wire) and PCM connector terminal No. 5. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open or short in Blue wire between PCM and EVAP canister purge volume control solenoid valve.
  3. Connect fused battery voltage to EVAP canister purge volume control solenoid valve terminals. (Scheme 25) Air should only pass through "A" and "B" ports with battery voltage applied. If operation is as specified, go to next step. If operation is not as specified, replace EVAP canister purge volume control solenoid valve and retest system.
  4. Check PCM connector pins for damage or corrosion. Check all circuit connectors for clean, tight fit. If fault is still present, repeat procedure starting at step 1).
  1. Turn ignition off. Disconnect EVAP canister vent control valve harness connector. (Scheme 26) Turn ignition on. Using a DVOM, measure voltage between EVAP canister vent control valve harness connector terminal No. 1 (Brown wire) and ground. If battery voltage is present, go to next step. If battery voltage is not present, check and repair for blown fuse, open or short in Brown wire. See WIRING DIAGRAMS article.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 108 and EVAP canister vent control valve harness connector terminal No. 2 (Purple wire). see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open or short in Purple wire between PCM and EVAP canister vent control valve.
  3. Check and repair rubber tube to EVAP canister vent control valve for obstructions or damage. Check EVAP canister vent control valve. See «DTC P0440 OR P1440»(ref-18071-S18946807012000122900000) EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM. If no faults are found, check PCM harness connector for corrosion or terminal damage. Repair as necessary.
  1. Check rubber hose to EVAP control system pressure sensor for damage or clogging. Repair as necessary. Loosen and retighten 2 ground wires located on intake manifold near fuel injectors. Disconnect EVAP control system pressure sensor harness connector. (Scheme 28) Turn ignition on. Using DVOM, measure voltage between EVAP control system pressure sensor harness connector terminal No. 3 (Red wire) and ground. If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, check and repair for open or short in Red wire between PCM and EVAP control system pressure sensor.
  2. Turn ignition off. Using DVOM, check continuity between EVAP control system pressure sensor harness connector terminal No. 1 (Black wire) and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between PCM and EVAP control system pressure sensor.
  3. Leave ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between EVAP control system pressure sensor harness connector terminal No. 2 (White wire) and PCM connector terminal No. 67. see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open or short in White wire between PCM and EVAP control system pressure sensor.
  4. Check EVAP canister purge volume control solenoid valve and EVAP canister vent control valve. See «DTC P0440»(ref-18071-S18946807012000122900000): EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM. Repair or replace as necessary. If components are okay, go to next step.
  5. Remove EVAP control system pressure sensor. Reconnect harness connectors. Connect vacuum pump to vacuum port. Turn ignition on. Measure voltage between ground and EVAP control system pressure sensor harness connector terminal No. 2 (White wire) by backprobing. Without vacuum applied, voltage should be 3.0-3.6 volts. Apply 2.8 in. Hg to sensor. With vacuum applied, voltage should be about 0.4-0.6 volt. If voltage is not as specified, replace EVAP control system pressure sensor. If voltage is as specified, go to next step.
  6. Check EVAP purge line for cracks. Inspect EVAP system components for damage or poor connections. Remove EVAP canister with EVAP canister vent control valve attached. See VACUUM DIAGRAMS article for canister location. Turn EVAP canister over and check for water leaking from EVAP canister vent control valve. If water is not leaking from valve, go to next step. If water is leaking from valve, weigh EVAP canister with valve attached. If canister is less than 4.0 lbs. (1.8 kg), go to next step. If canister is equal to or more than 4.0 lbs. (1.8 kg), replace EVAP canister and retest system.
  7. Disconnect and reconnect harness connectors in circuit. Check PCM connector for damage or corrosion. Repair as necessary.

Scheme 28

Scheme 28
Scheme 28
  1. Turn ignition off. Disconnect PCM harness connector and combination meter harness connectors. see scheme 1 Using DVOM, check continuity between combination meter harness connector terminal No. 5 and PCM harness connector terminal No. 26 (Purple/Red wire). see scheme 2and (Scheme 29). If continuity exists, go to next step. If continuity does not exist, repair open or short in Purple/Red wire between PCM and combination meter harness connectors.
  2. Reconnect all connectors. Check speedometer operation. If speedometer does not function, disconnect VSS harness connector. Remove VSS from transaxle. Check resistance between VSS connector terminals. If resistance is 250 ohms, go to next step. If resistance is not 250 ohms, replace VSS and retest system.
  3. Set DVOM to AC scale. Connect DVOM leads to VSS connector terminals. Turn VSS pinion gear to generate voltage. Voltage should generate about 0.5 volt (AC). If voltage is as specified, replace vehicle speed sensor. If VSS unit is okay, repair PCM pin terminals and/or harness connectors.

Scheme 29

Scheme 29
Scheme 29
  1. Turn ignition off. Disconnect IAC valve harness connector. (Scheme 30) Turn ignition on. Using DVOM, measure voltage between IAC valve harness connector terminal No. 1 (Brown wire) and ground. If battery voltage is present, go to next step. If battery voltage is not present, check appropriate fuse. See WIRING DIAGRAMS article. If fuse is okay, repair open or short in Brown wire between IAC valve and fuse block.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Check continuity between PCM harness connector terminal No. 101 and IAC valve harness connector terminal No. 2 (Light Blue wire). see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open or short in Light Blue wire between IAC valve and PCM.
  3. Measure resistance between IAC valve terminals. Resistance should be approximately 10 ohms at 77°F (25°C). If resistance is not as specified, service IAC valve plunger and spring. If resistance is as specified, IAC valve is okay. Check PCM connector terminals for corrosion or damage. Repair as necessary.

Scheme 30

Scheme 30
Scheme 30
  1. Turn ignition off. Disconnect closed Throttle Position (TP) switch harness connector. Turn ignition on. Using DVOM, measure voltage between closed TP switch harness connector terminal No. 5 (Brown wire) and ground. (Scheme 31) If battery voltage is present, go to next step. If battery voltage is not present, check for blown 10-amp fuse or open or short in Brown wire. Repair or replace as required.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 27 and closed TP switch harness connector terminal No. 6 (Yellow wire). If continuity exists, go to next step. If continuity does not exists, repair open or short in Yellow wire.
  3. Adjust closed TP switch as necessary. See ADJUSTMENTS article. If closed TP switch adjustment is okay, go to next step.
  4. Ensure engine is warmed to operating temperature. Turn ignition off. Disconnect closed TP switch harness connector. Check continuity between TP sensor terminals No. 5 (Brown wire) and No. 6 (Yellow wire) as follows: With accelerator closed, continuity should exist. With accelerator partially opened, continuity should not exist. If continuity is not as specified, replace closed TP switch. If continuity is as specified, disconnect harness connectors and check for damage or corrosion. Repair as necessary.

Scheme 31

Scheme 31
Scheme 31
  1. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Disconnect Transmission Control Module (TCM) harness connector. (Scheme 32) Using DVOM, check continuity between the following harness connector terminals: see scheme 2and (Scheme 33). PCM harness connector terminal No. 24 and TCM harness connector terminal No. 10 (Yellow/Brown wire). PCM harness connector terminal No. 29 and TCM harness connector terminal No. 11 (Yellow/Green wire). PCM harness connector terminal No. 30 and TCM harness connector terminal No. 12 (Yellow/Red wire). If continuity does not exist, repair open wires as necessary. If continuity exists, go to next step.
  2. Using DVOM, check continuity between ground and PCM harness connector terminals No. 24 (Yellow/Brown wire), No. 29 (Yellow/Green wire) and No. 30 (Yellow/Red wire). see scheme 2 If continuity exists, repair short in wires as necessary. If continuity does not exist, go to next step.
  3. Check PCM pins and terminals for damage and check connection of PCM harness connector. Reconnect PCM harness connector and retest.

Scheme 32

Scheme 32
Scheme 32

Scheme 33

Scheme 33
Scheme 33

Turn ignition on. Erase DTCs from PCM memory. See CLEARING CODES in TESTS W/CODES - INTRODUCTION article. If DTC P0605 is reset, replace PCM.

  1. Disconnect vacuum hose and connect vacuum "T" in line between MAP/BARO solenoid and AP sensor. Connect vacuum gauge to vacuum "T". Start engine and allow to idle. While monitoring vacuum gauge, check vacuum at hose. If vacuum is present, go to next step. If vacuum is not present, check vacuum hoses for damage or poor connection. If hoses are okay, check fuel intake system for vacuum leaks. Repair or replace if necessary.
  2. Turn ignition off. Disconnect MAP/BARO solenoid harness connector. Using DVOM, measure voltage between MAP/BARO solenoid harness connector terminal No. 1 (Red wire) and ground. If battery voltage is present, go to next step. If battery voltage is not present, repair blown fuse or open in Red wire. See WIRING DIAGRAMS article.
  3. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, measure voltage between PCM harness connector terminal No. 69 and MAP/BARO solenoid harness connector terminal No. 2 (Gray/Red wire). If battery voltage is present, go to next step. If battery voltage is not present, check for blown 10-amp fuse or short in Gray/Red wire.
  4. Check AP sensor. See «DTC P0105»(ref-18071-S08617428522000122900000) ABSOLUTE PRESSURE (AP) SENSOR. Repair as necessary. If AP sensor is okay, apply battery voltage and ground to MAP/BARO solenoid terminals No. 1 and 2. (Scheme 34) With battery voltage applied, air should pass between ports "A " and "B". Air should not pass between ports "A" and "C". With no voltage applied, air should pass between ports "A" and "C". Air should not pass between ports "A" and "B". Replace MAP/BARO solenoid if airflow is not as specified. If solenoid valve is okay, disconnect and reconnect harness connectors in circuit.

Scheme 34

Scheme 34
Scheme 34

This DTC is set when vehicle will not enter closed loop. See DTC P0130, P0133 OR P0134 FRONT HEATED OXYGEN SENSOR (HO2S) for testing procedures.

  1. Turn ignition off. Disconnect ignition coil 2-pin harness connector. (Scheme 20) Turn ignition on. Using DVOM, measure voltage between ignition coil harness connector Black/Red wire and ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open or short in Black/Red wire as necessary and retest system.
  2. Turn ignition off. Disconnect power transistor harness connector. (Scheme 20) Using DVOM, check continuity between power transistor harness connector terminal No. 2 (Black wire) and ground. (Scheme 21) If continuity does not exist, repair open in Black wire. If continuity exists, go to next step.
  3. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 1 and power transistor harness connector terminal No. 1 (White/Black wire). see scheme 2and (Scheme 21). If continuity does not exist, repair open in White/Black wire as necessary. If continuity exists, go to step 6).
  4. Turn ignition off. Disconnect ignition coil harness connector. (Scheme 20) Strip off tape covering resistor and condenser. Disconnect resistor connector. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between resistor harness connector Green wire terminal and ignition coil harness connector Green wire terminal. If continuity exists, go to next step. If continuity does not exist, repair open in Green wire and retest system.
  5. Check continuity between resistor harness connector Orange/Black wire terminal and PCM harness connector terminal No. 2 (Orange/Black wire). see scheme 2 If continuity does not exist, repair open in Orange/Black wire. If continuity exists, go to step 8).
  6. Disconnect ignition coil harness connector. Using DVOM, measure resistance between connector terminals. Resistance should be approximately 1.0 ohm at 68°F (20°C). Measure resistance between ignition coil secondary tower and Blue wire (positive) terminal of ignition coil connector. Resistance should be about 10,000 ohms at 68°F (20°C). If resistance is as specified, go to next step. If either resistance is not as specified, replace ignition coil and retest system.
  7. Disconnect camshaft position sensor/power transistor harness connector and ignition coil harness connector. Check resistance between power transistor harness connector terminal No. 2 and ignition coil harness connector Blue wire. If zero ohm (no resistance) is present, replace the distributor. If resistance is other than zero ohm is present, go to next step.
  8. Disconnect resistor harness connector. Measure resistance between resistor terminals. Resistance should be 2200 ohms at 77°F (25°C). If resistance is as specified, disconnect harness connectors and check for damage or corrosion. Repair as necessary. If resistance is not as specified, replace resistor and retest system.
  1. Turn ignition off. Disconnect EGR control solenoid valve harness connector. (Scheme 35) Turn ignition on. Using DVOM, measure voltage between EGR control solenoid valve harness connector terminal No. 1 (Red wire) and ground. If battery voltage does not exist, check for blown fuse or open or short in Red wire. If battery voltage exists, go to next step.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between EGR control solenoid valve harness connector terminal No. 2 (Pink wire) and PCM harness connector terminal No. 103 (Pink wire). see scheme 2 If continuity exists, go to next step. If continuity does not exist, repair open in Pink wire between PCM and EGR control solenoid valve.
  3. Connect battery voltage to EGR control solenoid valve terminals. (Scheme 34) With battery voltage connected, air should pass only through ports "A" and "B". With battery voltage disconnected, air should pass only through ports "A" and "C". If solenoid valve operation is as specified, go to next step. If solenoid valve operation is not as specified, replace EGR control solenoid valve and retest system.
  4. Disconnect and reconnect harness connectors in circuit. Check all connectors for corrosion or terminal damage. Repair as necessary and retest system.

Scheme 35

Scheme 35
Scheme 35
  1. Turn ignition off. Disconnect EGR temperature sensor harness connector. Turn ignition on. Using DVOM, measure voltage between EGR temperature sensor harness connector terminal No. 1 (Blue/Yellow wire) and ground. If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, repair fault in Blue/Yellow wire between PCM and EGR temperature sensor.
  2. Turn ignition off. Using DVOM, check continuity between EGR temperature sensor harness connector terminal No. 2 (Black wire) and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between PCM and EGR temperature sensor.
  3. Reconnect all connectors. Start engine and allow to idle. As engine warms up, measure voltage between EGR temperature sensor terminals by backprobing. See EGR TEMPERATURE SENSOR SPECIFICATIONS table. If voltage is not as specified, replace EGR temperature sensor. If voltage is as specified, turn ignition off. Check PCM connector terminals for damage or corrosion. Repair or replace as necessary and retest system.
Temperature - °F (°C)(1) Volts
32 (0)4.61
122 (50)2.53
212 (100)0.87
(1) Voltage values are approximate.
(1)Voltage values are approximate.

EGR TEMPERATURE SENSOR SPECIFICATIONS

  1. Check vacuum lines and hoses for cracks, clogging or improper connection. Repair as necessary and go to next step.
  2. Raise and support vehicle enough to allow drive wheels to clear floor. Start engine and warm to operating temperature. Place shift lever in "1" position and operate engine at 2000 RPM. If EGR control solenoid valve can be heard operating with engine running, go to next step. If EGR control solenoid valve cannot be heard operating with engine running, check EGR control solenoid valve. See «DTC P1400: EGR CONTROL SOLENOID VALVE»(ref-18071-S17884858262000122900000) .
  3. If EGR control solenoid valve is okay, check EGR valve. See I - SYSTEM & COMPONENT TESTS article for testing EGR valve. Replace as necessary. If EGR valve is okay, check EGR control backpressure transducer valve. See I - SYSTEM & COMPONENT TESTS article. Replace as necessary. If EGR control backpressure transducer valve is okay, go to next step.
  4. Check circuit harness connectors for terminal damage or corrosion. If connectors are okay, check EGR temperature sensor. See «DTC P1401: EGR TEMPERATURE SENSOR»(ref-18071-S41070811282000122900000) . Replace as necessary.
  1. Check EVAP canister for damage or leaking. See I - SYSTEM & COMPONENT TESTS article. If canister is okay, go to next step. If canister is not okay, replace as necessary and retest system.
  2. Start engine and warm to operating temperature. Turn ignition off. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port and install vacuum gauge. See EMISSION SYSTEMS in THEORY & OPERATION article. Start engine and let idle for at least 80 seconds. While monitoring vacuum gauge, accelerate engine to 2000 RPM. Release accelerator pedal and note vacuum. Vacuum should exist with engine speed at 2000 RPM and no vacuum should exist at idle. If operation is as specified, go to next step. If operation is not as specified, turn ignition off. Check vacuum lines for clogging and check EVAP canister purge volume control solenoid valve. See «DTC P0443 OR P1444: EVAP CANISTER PURGE VOLUME»(ref-18071-S06708894422000122900000) CONTROL SOLENOID VALVE. Replace as necessary and retest system.
  3. Check vacuum line to EVAP control system pressure sensor. (Scheme 28) Repair or replace as necessary. If vacuum line is okay, remove EVAP control system pressure sensor with harness connector connected. Using vacuum pump, apply 2.8 in Hg to EVAP control system pressure sensor vacuum port. Using DVOM, measure voltage between EVAP control system pressure sensor harness connector terminal No. 2 (center wire) and ground by backprobing. With vacuum applied, voltage should be.4-.6 volt. Without vacuum applied, voltage should be 3.0-3.6 volts. If voltage is as specified, go to next step. If voltage is not as specified, replace EVAP control system pressure sensor and retest system.
  4. Check EVAP canister vent control valve and "O" ring. See «DTC P0446, P1446 OR P1448: EVAP CANISTER VENT CONTROL VALVE»(ref-18071-S23663367182000122900000). If valve is okay, check EVAP purge line for damage or leaks. Repair or replace as necessary. If purge line is okay, check harness connectors for pin damage or corrosion. Repair as necessary and retest system.
  1. Turn ignition off. Disconnect vacuum cut valve by-pass valve harness connector. (Scheme 28) Turn ignition on. Using DVOM, measure voltage between vacuum cut valve by-pass valve harness connector terminal No. 2 (Brown wire) and ground. If battery voltage is present, go to next step. If voltage is not present, check fuse. See WIRING DIAGRAMS article. If fuse is okay, repair open or short in Brown wire between fuse box and vacuum cut valve by-pass valve.
  2. Turn ignition off. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between vacuum cut valve by-pass valve harness connector terminal No. 1 (Purple/Red wire) and PCM harness connector terminal No. 117. see scheme 2 If continuity exists, go to next step. If continuity does not exist, check and repair open in Purple/Red wire between PCM and vacuum cut valve by-pass valve. Reconnect all connectors and retest system.
  3. Remove vacuum cut valve by-pass valve. Ensure air does not flow through valve ports with harness connector disconnected. Apply battery voltage between vacuum cut valve by-pass valve terminals, ensure air passes through valve ports. If vacuum cut valve by-pass valve operation is as specified, vacuum cut valve by-pass valve is okay. If vacuum cut valve by-pass valve operation is not as specified, replace vacuum cut valve by-pass valve.
  1. Remove EVAP vacuum cut valve with vacuum cut valve by-pass valve connected. Apply battery voltage between vacuum cut valve by-pass valve terminals. (Scheme 25) With battery voltage applied, air should flow freely through ports "A" and "B" in both directions. If operation is as specified, check and repair EVAP purge line between canister and fuel tank (clogging). If operation is not as specified, check and repair by-pass hoses (clogging). If hoses are okay, go to next step.
  2. Check vacuum cut valve by-pass valve. See «DTC P1490: EVAP VACUUM CUT VALVE BY-PASS VALVE»(ref-18071-S33084818002000122900000). Check vacuum cut valve. Remove vacuum cut valve and disconnect hoses to by-pass valve. Plug vacuum cut valve ports "C" and "D". Apply vacuum to port "A" and ensure there is no suction at port "B". (Scheme 36) Apply vacuum to port "B" and verify that there is suction at port "A". Blow into port "B" and verify that a restriction in air flow exists out of port "A". Remove your fingers from ports "C" and "D". Blow into port "A" and verify air flows freely out of port "C". Blow air into port "B" and verify it floes freely out of port "D". If operation is as specified, go to next step. If operation is not as specified, replace vacuum cut valve and retest system.
  3. Remove and check EVAP system control pressure sensor. See «DTC P1447: EVAP CONTROL SYSTEM PURGE FLOW MONITORING»(ref-18071-S04603865172000122900000). Repair or replace as necessary. If pressure sensor is okay, go to next step.
  4. Check EVAP canister vent control valve. See «DTC P0446, P1446 OR P1448: EVAP CANISTER VENT CONTROL VALVE»(ref-18071-S23663367182000122900000). Replace as necessary and retest system. If vent control valve is okay, check EVAP canister. See «DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR»(ref-18071-S13972897472000122900000). Repair or replace as necessary. If canister is okay, check for an intermittent fault in wiring connectors or repeat procedure from step 1).

Scheme 36

Scheme 36
Scheme 36
  1. Turn ignition off. Disconnect PCM and Transmission Control Module (TCM) harness connectors. see scheme 1and (Scheme 32). Using DVOM, check continuity between PCM harness connector terminal No. 7 and TCM harness connector terminal No. 45 (Purple wire). see scheme 2and (Scheme 33). If continuity exists, go to next step. If continuity does not exist, repair open in Purple wire between PCM and TCM.
  2. Disconnect and reconnect PCM and TCM harness connectors. Check terminals for damage or corrosion. Repair as necessary and retest system.

MIL 0208: COOLING FAN CIRCUIT

Note. Using the following diagnostic procedure assumes the presence of a current (hard) DTC or the ability to duplicate the setting of the DTC using described procedures, intermittent recreation procedures or a test drive under conditions stored in freeze frame data. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article. If DTC cannot be duplicated, proceed to TESTS W/O CODES article for diagnosis by symptom.

  1. Turn ignition off. Start engine. Turn A/C switch and blower fan switch to ON position. Allow engine to idle for several minutes. Verify cooling fan operates at low speed. If fan operates at low speed, go to next step. If fan does not operate at low speed, go to step 3).
  2. Turn ignition off. Turn A/C switch and blower fan switch to OFF position. Disconnect Engine Coolant Temperature (ECT) sensor harness connector. (Scheme 12) Connect 150-ohm resistor between ECT sensor harness connector terminals. Restart engine. Verify cooling fan operates at higher than low speed. If cooling fan does not operate as specified, go to step 7). If cooling fan operates as specified, check cooling system for leaks, radiator cap pressure and thermostat operation. Repair as necessary. Inspect ECT sensor. See «DTC P0115 OR P0125: ENGINE COOLANT TEMPERATURE (ECT) SENSOR»(ref-18071-S20700839392000122900000). Replace as necessary.
  3. Turn ignition off. Disconnect cooling fan relay No. 1 and cooling fan motor No. 2. (Scheme 37)and (Scheme 38). Turn ignition on. Using DVOM, measure voltage between ground and cooling fan relay No. 1 harness connector terminals No. 1, 3 and 6. (Scheme 39) If battery voltage is present, go to next step. If battery voltage is not present, repair blown fuse or open in appropriate wire between cooling fan relay No. 1 and appropriate fuse. See WIRING DIAGRAMS article.
  4. Turn ignition off. Disconnect cooling fan motors No. 1 and 2 harness connectors. Using DVOM, check continuity between cooling fan motor No. 1 harness connector terminal "a" and cooling fan relay No. 1 harness connector terminal No. 5 (Green/Black wire). (Scheme 40) Check continuity between cooling fan motor No. 2 harness connector terminal "e" and cooling fan relay No. 1 harness connector terminal No. 7 (Green/Red wire). (Scheme 39)and (Scheme 40). If continuity exists in both circuits, go to next step. If continuity does not exist in either circuit, repair open in appropriate wire.
  5. Using DVOM, check continuity between cooling fan motor No. 1 harness connector terminal "d" (Black wire) and ground. (Scheme 40) Also, check continuity between cooling fan motor No. 2 harness connector terminal "h" (Black wire) and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between appropriate connector and ground.
  6. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 14 and cooling fan relay No. 1 harness connector terminal No. 2 (Light Green/Red wire). see scheme 2and (Scheme 40). If continuity exists, go to step 10). If continuity does not exist, repair open in Light Green/Red wire.
  7. Turn ignition off. Disconnect cooling fan relays No. 2 and 3. (Scheme 38) Turn ignition on. Using DVOM, measure voltage between cooling fan relay No. 2 and 3 harness connector as follows: (Scheme 39) Terminal No. 1 (Brown wire) and ground. Terminal No. 3 (Green or Green/White wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, check for fault in appropriate wire, blown fuses or faulty connectors. See WIRING DIAGRAMS.
  8. Turn ignition off. Leave cooling fan relays No. 2 and 3 disconnected. Disconnect cooling fan motors No. 1 and 2 harness connectors. (Scheme 38) Using DVOM, check continuity as follows: (Scheme 39)and (Scheme 40). Between cooling fan motor No. 1 connector terminal "b" and cooling fan relay No. 2 connector terminal No. 5 (Green/Yellow wire). Between cooling fan motor No. 2 connector terminal "f" and cooling fan relay No. 3 connector terminal No. 5 (Green/Orange wire). Between cooling fan motor No. 1 connector terminal "c" (Light Green/Black wire) and cooling fan relay No. 2 connector terminal No. 6. Between ground and cooling fan relay No. 2 connector terminal No. 7 (Black wire). Between cooling fan motor No. 2 connector terminal "g" (Light Green/Red wire) and cooling fan relay No. 3 connector terminal No. 6. Between ground and cooling fan relay No. 3 connector terminal No. 7 (Black wire). If continuity exists, go to next step. If continuity does not exist, repair open in circuit.
  9. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 13 and cooling fan relay No. 2 and 3 connector terminal No. 2 (Light Green wire). see scheme 2and (Scheme 39). If continuity exists, go to next step. If continuity does not exist, repair open in Light Green wire between PCM and cooling fan relay.
  10. Using DVOM, check continuity of cooling fan relays as follows: (Scheme 41) With battery voltage applied between cooling fan relay terminals No. 1 and, continuity should exist between terminals No. 3 and 5 and between terminals No. 6 and 7. Without battery voltage applied, continuity should not exist between terminals No. 3 and 5 and between terminals No. 6 and 7. If continuity is as specified, go to next step. If continuity is not as specified, replace cooling fan relay.
  11. Disconnect cooling fan motor harness connectors. Connect positive terminal of 12-volt battery to terminal "a" of appropriate cooling fan motor. Connect negative terminal of battery to terminal "d" of appropriate cooling fan motor. Fan motor should operate at low speed.
  12. Disconnect appropriate cooling fan motor connector. Connect positive terminal of 12-volt battery to terminal "a" and negative terminal of battery to terminal "d" of appropriate cooling fan motor. (Scheme 42) Fan motor should operate at high speed. Connect positive terminal of battery to terminal "b" and negative terminal of battery to terminal "c" of cooling fan motor. Fan motor should operate at high speed. If motor does not operate as specified, replace cooling fan motor. If cooling fans and relays are okay, check PCM pin terminals and/or harness connectors.

Scheme 37

Scheme 37
Scheme 37

Scheme 38

Scheme 38
Scheme 38

Scheme 39

Scheme 39
Scheme 39

Scheme 40

Scheme 40
Scheme 40

Scheme 41

Scheme 41
Scheme 41

Scheme 42

Scheme 42
Scheme 42

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