Engine Controls - Tests W/codes: Diagnosis Nissan Altima U13

DIAGNOSTIC MODES

Self-diagnostic system can detect engine control system malfunctions and store related trouble codes. Trouble codes, including intermittent codes, are stored in ECM memory and are available for retrieval unless codes have been cleared.

Self-diagnostic system uses single or dual Light Emitting Diodes (LED), located on ECM. See ECM LOCATION table. For system application, see SELF-DIAGNOSTIC SYSTEM table.

ECM LOCATIONS

SELF-DIAGNOSTIC SYSTEM

Mode II (Self-Diagnostics)

When Mode II is accessed (engine not running), codes stored in ECM memory will be flashed by CHECK ENGINE light (if equipped) and Red LED on side of ECM.

Long flashes (.6 second) indicate first digit of code. Short flashes (.3 second) indicates second digit of code. For example: one long flash followed by 2 short flashes indicate a Code 12. (Scheme 1)

Scheme 1

Mode III (Self-Diagnostics)

When Mode III is accessed, codes stored in ECM memory will be flashed by Green LED and Red LED on side of ECM. Green LED will flash first digit of code, while Red LED will flash second digit of code. For example: 3 flashes of Green LED followed by 5 flashes of Red LED indicate a Code 35.

Mode V (Test Mode)

Mode V represents a real-time diagnostic test of crank angle sensor, ignition signal. This mode is accessed for an in-bay running test of vehicle. Red and Green LEDs must be monitored carefully during this test, with special attention paid to number of flashes before each pause.

Malfunction code will be displayed only once and will not be stored in memory. If Red LED blinks on and off evenly, a fault exists in crank angle sensor. If Green LED flashes twice before a pause, a fault exists in airflow meter. If Red LED blinks 3 times before a pause, a fault exists in fuel pump circuit. If Green LED blinks 4 times before a pause, a fault exists in ignition signal.

TROUBLE CODE DEFINITION

Note. Not all trouble codes will activate CHECK ENGINE light.

TROUBLE CODE IDENTIFICATION CHART

DIAGNOSTIC TROUBLE CODE (DTC) TESTS

Note. Procedures using Nissan Consult Tester (J-38465) will be provided when available. If circuit test is being performed without Consult tester, use alternate test procedure.

Scheme 2

Scheme 3

DTC 11: CRANKSHAFT POSITION (CKP) SENSOR

1. Check Power Supply - Turn ignition off and disconnect CKP sensor harness connector. Turn ignition on. Measure voltage between CKP sensor harness connector terminal "b" and ground. (Scheme 4) If battery voltage is present, go to next step. If battery voltage is not present, repair wiring harness and/or connector as necessary.
2. Check Ground Circuit - Turn ignition off. Leave CKP sensor harness connector disconnected. Check for continuity between CKP sensor harness connector terminal "a" and ground. (Scheme 5) If continuity is present, go to next step. If continuity is not present, repair wiring harness and/or connector as necessary.
3. Check Input Signal Circuit - Turn ignition off. Disconnect ECM harness connector. Ensure continuity exists between CKP sensor harness connector terminal "c" (Yellow wire) and ECM connector terminals No. 31 and 40 (one degree signal), and between CKP terminal "d" and ECM connector terminals No. 22 and 30 (180 degree signal). (Scheme 3)and (Scheme 6). If continuity is present, go to next step. In continuity is not present, repair wiring harness or connectors as necessary.
4. Check Component - Inspect CKP sensor. See «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. If CKP sensor is defective, replace as necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article. If CKP sensor is okay, repair ECM pin terminals and/or wiring harness connector.

Scheme 4

Scheme 5

Scheme 6

DTC 12: MASS AIRFLOW (MAF) SENSOR

1. Check Power Supply - Turn ignition off. Disconnect MAF sensor harness connector. (Scheme 7) Turn ignition on. Measure voltage between MAF sensor harness connector terminal "b" and ground. (Scheme 8) If battery voltage is present, go to next step. If battery voltage is not present, repair harness or connectors as necessary.
2. Check Ground Circuit - Turn ignition off. Disconnect ECM harness connector. Check continuity between MAF sensor connector terminal "c" and ECM terminal No. 17. (Scheme 3)and (Scheme 9). If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
3. Check Input Signal Circuit - Check continuity between MAF sensor connector terminal "d" and ECM harness connector terminal No. 16. (Scheme 3)and (Scheme 10). If continuity is not present, repair harness or connectors as necessary.
4. Check MAF Sensor - Inspect MAF sensor. See «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. Replace MAF sensor if necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article. If MAF sensor is okay, repair ECM pin terminals and/or wiring harness connector.

Scheme 7

Scheme 8

Scheme 9

Scheme 10

DTC 13: ENGINE COOLANT TEMPERATURE (ECT) SENSOR

1. Check Power Supply - Turn ignition off and disconnect ECT sensor harness connector. (Scheme 11) Turn ignition on. Measure voltage between ECT sensor harness connector terminal "a" and ground. (Scheme 12) If voltage is about 5 volts, go to next step. If voltage is not as specified, repair harness or connectors as necessary.
2. Check Ground Circuit - Turn ignition off. Check for continuity between terminal "b" and engine ground. (Scheme 13) If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
3. Check Component - Inspect ECT sensor. See «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. Replace ECT sensor if necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article. If ECT sensor is okay, repair ECM pin terminals and/or wiring harness connector.

Scheme 11

Scheme 12

Scheme 13

DTC 14: VEHICLE SPEED SENSOR (VSS)

1. Check Speedometer Operation - VSS is built into speedometer. Ensure speedometer operates properly. If speedometer operates properly, go to next step. If speedometer does not operate properly, remove VSS from transaxle. Set voltmeter on AC scale. Turn VSS pinion gear. Connect voltmeter to VSS connector terminals. Voltage should be about 0.5 volt. If voltage is not correct, replace vehicle speed sensor. If voltage is correct, go to next step.
2. Check Input Signal Circuit - Turn ignition off. Disconnect ECM and combination meter wiring harness connector. Check harness continuity between ECM terminal No. 32 and combination meter terminal No. 5 (models without head-up display) or No. 58 (models with head-up display). (Scheme 14) If continuity is present, check ECM wiring harness connector and repair or replace as necessary. If continuity is not present, repair harness or connectors as necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article.

Scheme 14

DTC 21: IGNITION SIGNAL

1. Check Power Supply - Turn ignition off. Disconnect ignition coil harness connector. (Scheme 15) Turn ignition on. Measure voltage between ignition coil harness connector terminal "a" and ground. (Scheme 18) If battery voltage is not present, check wire between ignition coil and ignition switch for open or short circuit. If battery voltage is present, go to next step.
2. Check Ground Circuit - Turn ignition off. Disconnect power transistor and resistor/condenser wiring harness connector. (Scheme 16)and (Scheme 17). Check continuity between ignition coil connector terminal "b" and following: power transistor connector terminal "i" and resistor/condenser connector terminal "d". (Scheme 19) Check continuity between power transistor connector terminal "h" and engine ground. If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
3. Check Input Signal Circuit - Turn engine off. Leave power transistor and resistor/condenser wiring harness disconnected. Disconnect ECM harness connector. Check continuity between resistor/condenser connector terminal "c" and ECM terminal No. 3. (Scheme 20) If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
4. Check Output Signal Circuit - Ensure ignition is off. Check for continuity between ECM terminal No. 1 and power transistor connector terminal "g". (Scheme 21) If continuity is present, inspect ignition coil and power transistor. See «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. Replace ignition coil and/or power transistor if necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article. If continuity is not present, repair harness or connectors as necessary.

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

DTC 31: ECM

Turn ignition on. Erase diagnostic test Mode II (self-diagnostic results) memory. Perform diagnostic test Mode II (self-diagnostic results). If ECM displays DTC 31 again, replace ECM.

DTC 32: EGR FUNCTION

1. Check Vacuum Source To EGR Valve - Start engine and warm to operating temperature. Disconnect hose from EGR valve and check vacuum. Vacuum should not be present. Raise engine speed to about 2000 RPM and check vacuum. Vacuum should be present. If vacuum is not as specified, go to next step. If vacuum is as specified, inspect EGR valve and EGR Control-BPT valve. See «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. Repair or replace as necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article.
2. Check Control Function - If vacuum is not present at about 2000 RPM, measure voltage between ECM terminal No. 105 and ground. (Scheme 3)and (Scheme 22). At idle, voltage should be about zero volts. At 2000 RPM, voltage should be battery voltage. If voltage is not as specified, go to next step. If voltage is as specified, inspect vacuum hose for clogging, cracks or proper connection. Repair vacuum hose as necessary.
3. Check Power Supply - Turn ignition off. Disconnect EGR and canister control solenoid valve harness connector. (Scheme 23) Turn ignition on. Measure voltage between wiring harness connector terminal "b" and ground. (Scheme 24) If battery voltage is not present check 10 amp fuse, wiring harness and harness connectors. Repair or replace as necessary. If battery voltage is present, go to next step.
4. Check Output Signal Circuit - Turn engine off. Leave ECM disconnected. Check continuity between ECM terminal No. 105 and EGR and canister control solenoid valve harness connector terminal "a". (Scheme 3)and (Scheme 24) for terminal identification. If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
5. Check Component - Inspect EGR and canister control solenoid valve. See «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. Measure resistance of EGR temperature sensor. See the «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. Replace EGR and canister control solenoid valve and/or EGR temperature sensor if necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article.
6. Check Component Using Consult Tester (J-38465) - Turn ignition off and connect Consult tester. Connect ECM harness connector and EGR and canister control solenoid valve harness connector. Turn ignition on. Using Consult tester, perform EGRC SOL/V CIRCUIT in FUNCTION TEST mode. Turn EGR and canister control solenoid valve on and off using Consult tester in ACTIVE TEST mode. Replace EGR and canister control solenoid valve if operating sounds are not heard. Perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article.

Scheme 22

Scheme 23

Scheme 24

DTC 33: OXYGEN SENSOR

1. Check System Function - During self-diagnostic test Mode II, Red LED on ECM and MIL on instrument panel should blink 5 times within 10 seconds when engine speed is about 2000 RPM. If lights are as specified, testing is complete. If lights are not as specified, go to next step.
2. Check Input Signal Circuit - Turn ignition off. Disconnect oxygen sensor harness connector and ECM harness connector. Check continuity between oxygen sensor connector terminal and ECM connector terminal No. 19. (Scheme 3)and (Scheme 24). If continuity is present, replace oxygen sensor and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article. If continuity is not present, repair harness or connectors as necessary.
3. Check Voltage Using Consult Tester (J-38465) - Turn ignition off. Connect Consult tester, oxygen sensor harness connector and ECM harness connector. Select DATA MONITOR mode with Consult tester. Ensure M/R F/C MNT indicates RICH and LEAN 5 times within 10 seconds when engine speed is about 2000 RPM. If conditions are as specified, system is okay and testing is complete. If conditions are not as specified, go to step 2).

Scheme 25

DTC 34: KNOCK SENSOR

1. Check Input Signal Circuit - Turn ignition off. Disconnect ECM. Disconnect engine harness No. 2 connector. (Scheme 26) Check continuity between engine harness No. 2 connector terminal "g" (White wire) and ECM terminal No. 27. (Scheme 3)and (Scheme 27). If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
2. Check Component - Inspect knock sensor. See «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. Replace knock sensor if necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article. If knock sensor is okay, repair ECM pin terminals and/or wiring harness connector.

Scheme 26

Scheme 27

DTC 35: EGR TEMPERATURE SENSOR (CALIF.)

1. Check Power Supply - Turn ignition off. Disconnect EGR temperature sensor harness connector. (Scheme 28) Turn ignition on. Measure voltage between EGR temperature sensor connector terminal "a" (Red/Blue wire) and ground. (Scheme 29) If voltage is 5 volts or less, go to next step. If voltage is more than 5 volts, repair harness or connectors as necessary.
2. Check Ground Circuit - Turn ignition off. Ensure continuity between EGR temperature sensor connector terminal "b" (Black wire) and engine ground. (Scheme 30) If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
3. Check Component - Inspect EGR temperature sensor. See the «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. Replace EGR temperature sensor if necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article. If EGR temperature is okay, repair ECM pin terminals and/or wiring harness connector.

Scheme 28

Scheme 29

Scheme 30

DTC 43: THROTTLE POSITION (TP) SENSOR

1. Check Power Supply - Turn ignition off and disconnect TP sensor harness connector. (Scheme 31) Turn ignition on. Measure voltage between TP sensor connector terminal "c" (Red/Yellow wire) and ground. (Scheme 32) If voltage is about 5 volts, go to next step. If voltage is not as specified, repair harness or connectors as necessary.
2. Check Ground Circuit - Turn ignition off. Check continuity between TP sensor connector terminal "a" (Black wire) and engine ground. (Scheme 33) If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
3. Check Input Signal Circuit - Disconnect ECM harness connector. (Scheme 2) Ensure continuity exists between ECM connector terminal No. 20 and TP sensor connector terminal "b" (White wire). (Scheme 3)and (Scheme 34). If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
4. Check Component - Inspect TP sensor. See «SYSTEM/COMPONENT TESTS»(ref-17477) article in the ENGINE PERFORMANCE section. Replace TP sensor if necessary and perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article. If TP sensor is okay, repair ECM pin terminals and/or wiring harness connector.

Scheme 31

Scheme 32

Scheme 33

Scheme 34

DTC 45: INJECTOR LEAK

1. Clear Self-Learning Data - Start engine and bring to operating temperature. Stop engine and disconnect Mass Airflow (MAF) sensor connector. Start engine and run for at least 30 seconds at 2000 RPM. Stop engine and connect MAF sensor connector. Ensure DTC 12 is displayed in diagnostic test Mode II. Erase self-diagnosis memory. Ensure DTC 55 is displayed in diagnostic test Mode II.
2. Clear Self-Learning Data Using Consult Tester (J-38465) - Select SELF-LEARNING CONT in ACTIVE TEST mode. Clear self-learning control coefficient by touching CLEAR.
3. Perform Diagnostic Test Mode II (Self-Diagnostic Results) - If DTC 45 does not return, test is complete. If DTC 45 does return, release fuel pressure. Remove injector assembly. DO NOT remove fuel hose or injector from injector gallery. Turn ignition on. Ensure fuel does not drip from injector(s). Repair or replace injector(s) as necessary. Perform «FINAL CHECK»(ref-17456-S13717969332000122900000) in this article.