Engine Controls - Tests W/codes - 2.0L: Diagnosis Nissan 200SX S14

DIAGNOSTIC TROUBLE CODES (DTCs)

The Engine Control Module (ECM) monitors several different engine control circuits. If a malfunction occurs, ECM will record a Diagnostic Trouble Code (DTC). The next time engine is started and the same malfunction is detected ECM will turn on MIL signaling a DTC is in ECM memory.

After 3 consecutive drive cycles without a malfunction, ECM will turn off MIL, however DTC will be stored in ECM memory. If ECM does not detect a that fault for 40 drive cycles, DTC will be purged from ECM memory. ECM will purge a DTC for a misfire or fuel trim malfunction when fault is not detected for 80 drive cycles of engine with engine speed, coolant temperature, etc. similar to when malfunction first occurred.

Hard faults cause MIL to illuminate and remain on until the malfunction is repaired. If light comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined. If a sensor fails, ECM will use a substitute value in its calculations to continue engine operation. In this condition, vehicle is functional, but driveability will be affected.

VISUAL INSPECTION

Before proceeding with self-diagnostics, visually check the following and prepare vehicle as follows

1. Perform all necessary safety precautions to prevent personal injury or vehicle damage.
2. Block drive wheels. Set parking brake. Place shift lever in Park (A/T) or Neutral (M/T). DO NOT move shift lever during test unless specifically directed to do so.
3. Check condition of air cleaner and air ducting.
4. Check all vacuum hoses for leaks, restrictions and proper routing.
5. Check EEC system wiring harness connections for corrosion, damaged pins, loose wires and improper routing.
6. Check ECM, sensors and actuators for physical damage.
7. Check engine coolant and oil level.
8. Check battery condition. Turn off all lights and accessories. Ensure vehicle doors are closed when measuring voltage.
9. Check exhaust system for leaks.

Scheme 1

1. If use of an OBD-II type scan tool is not available, DTCs can be retrieved by changing MIL output from Mode 1 to Mode 2. Mode 1 is the normal malfunction warning mode. Mode 2 displays self-diagnostic results. NOTE: Before switching MIL to Mode 2, perform bulb check (key on engine off). If MIL is inoperative, check and repair MIL circuit as necessary.
2. To switch MIL output from Mode 1 to Mode 2, locate and gain access to ECM. See ECM LOCATION table. Turn ignition on. Using a screwdriver, turn test mode selector fully clockwise. (Scheme 1) After 2 seconds, turn test mode selector fully counterclockwise (back to original position). MIL should now be in Mode 2. When in Mode 2 with key on and engine off, MIL should begin flashing codes (Scheme 1): Turning Test Mode Selector ECM LOCATIONS Application Location 200SX Under Dash, Behind Center Console NOTE: DTCs retrieved by MIL may also be referred to as flash codes.
3. The 4-digit DTCs (flash codes) are read as two 2-digit numbers. The first 2-digit number is indicated by a series of long flashes followed by a series of short flashes. E.g. 1 long flash followed by 2 short flashes indicates DTC 0102. (Scheme 2) The DTCs retrieved by MIL are not numerically the same as DTCs retrieved from a scan tool.
4. Write down codes and repair in order retrieved. To determine which circuit test to use, see «DTC IDENTIFICATION»(ref-17820-S42243087372000122900000) table. After retrieving DTCs or performing a repair, clear DTCs from ECM memory.

Scheme 2

CLEARING CODES WITHOUT SCAN TOOL

Note. Clearing code procedure will clear the following: Diagnostic trouble codes. 1st trip diagnostic trouble codes. Freeze frame data. 1st trip freeze frame data. System readiness codes. Test values. Enter diagnostic Mode 2 as described in RETRIEVING CODES. See RETRIEVING CODES USING MIL . After retrieving codes in Mode II, turn test mode selector fully clockwise. Wait at least 2 seconds. Turn test mode selector fully counterclockwise. This will be erase DTCs from memory by switching PCM mode selector from diagnostic Mode 2, back to diagnostic Mode 1.

SELF-DIAGNOSTICS USING SCAN TOOL

Note. Procedures given are generic and may vary depending on equipment used. See scan tool manufacturers instructions for specifics.

RETRIEVING CODES USING SCAN TOOL

1. Ensure engine is warmed to normal operating temperature. If engine does not start, continue with testing. Turn ignition on. Ensure test equipment is properly attached.
2. Using the scan tool, select and enter the following data: Select vehicle and engine selection menu. Select year, engine, model and any additional information requested by scan tool. Select ECM. Select DTCs. Select DIAGNOSTIC TEST MODE RESULTS.
3. At this point, scan tool should display all DTCs. Write down codes in order displayed. If a communication problem exists between scan tool and ECM, check for loose power and data cables to scan tool. NOTE: If a DTC is retrieved, ECM may have stored data. See «FREEZE FRAME DATA»(ref-17820-S34466654182000122900000) . If desired, check freeze frame data before clearing codes. Clearing codes will erase freeze frame data.
4. To determine if codes will reappear, indicating a hard (non-intermittent) fault, clear codes and recheck for codes. See CLEARING CODES. If DTC immediately returns, malfunction is considered to be a hard fault. If a DTC does not immediately return, vehicle may need to be driven in a special pattern to cause code to reset. See «DRIVE CYCLES»(ref-17820-S14944108442000122900000) .
5. If one or more DTCs retrieved, service DTCs in order scan tool displayed them. Go to appropriate DTC test. If no DTCs or DTC P0000 (pass code) retrieved, proceed to «TESTS W/O CODES - 2.0L»(ref-17899) article.

CLEARING CODES USING SCAN TOOL

1. Ensure scan tool is properly connected. Select vehicle and engine selection menu (optional). Select year, engine, model and any additional information requested by scan tool.
2. Turn ignition on. Select DIAGNOSTIC TROUBLE CODES. Select ERASE. All codes should now be cleared from ECM memory. If problem has not been corrected or fault is still present, hard code will immediately be reset in ECM memory.

DIAGNOSTIC WORKFLOW

1. Verify Complaint. Get detailed information on conditions present when fault occurred.
2. Check and write down DTCs and freeze frame data. Erase DTCs.
3. Attempt to recreate conditions present when fault occurred (test drive etc.).
4. Recheck DTCs and data monitor information while duplication fault conditions.
5. If DTCs are retrieved, perform appropriate DTC testing.
6. If no DTCs are retrieved or only system okay DTC is retrieved, check suspect wiring for intermittents by wiggling wiring while checking data monitor.
7. If no response from scan tool attempted, retrieve DTCs using MIL.
8. Check ECM pin voltage values. See the «PIN VOLTAGE CHARTS»(ref-17819) article.
9. Ensure fault/symptom is repaired before returning vehicle.

DTC PO115 OR DTC PO125 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR

1. Check Ground Circuit Turn ignition switch to OFF position. Disconnect ECT harness connector. Using an ohmmeter, check continuity between harness connector terminal No. 1 (Black wire) and engine ground. If no continuity exists, repair open in Black wire. If continuity exists, go to next step.
2. Check Power Supply Turn ignition switch to ON position. Using a voltmeter, measure voltage between ECT sensor harness connector terminal No. 2 (Brown/Yellow wire) and ground. If voltage is not approximately 5 volts, repair fault in Brown/Yellow wire as required. If measured voltage is approximately 5 volts, go to next step.
3. Check Component Ensure ECT sensor is not damaged or contaminated. Check ECM and ECT sensor harness connectors for damage, corrosion or pushed-out pins. Repair if necessary. If no problems are found, ensure ignition is off. Measure resistance between ECT sensor connector terminals as follows: With temperature at 68°F (20°C), resistance should be 2100-2900 ohms. With temperature at 122°F (50°C), resistance should be 680-1000 ohms. With temperature at 194°F (90°C), resistance should be 236-260 ohms. If resistance is not as specified, replace ECT sensor.

DTC PO335 OR P1336 - CRANKSHAFT POSITION (CKP) SENSOR

1. Check Ground Circuit Turn ignition switch to OFF position. Disconnect CKP sensor harness connector. (Scheme 3) Using an ohmmeter, check continuity between CKP sensor harness connector terminal No. 2 (Black wire) and ground. If no continuity exists, repair open in Black wire. If continuity exists, go to next step.
2. Check Input Signal Circuit Disconnect ECM harness connector. Using an ohmmeter, check continuity between ECM harness connector terminal No. 53 and CKP sensor harness connector terminal No. 1 (White wire). If no continuity exists, repair open in White wire. If continuity exists, go to next step.
3. Check Component Inspect CKP sensor. See the «SYSTEM/COMPONENT TESTS - 2.0L»(ref-17821) article. Replace CKP sensor as required. Disconnect and reconnect harness connectors in circuit and perform «FINAL CHECK»(ref-17820-S16658626442000122900000).

Scheme 3