Engine Controls - Tests W/codes - 2.0L Turbo: Diagnosis Saab 900 II

SELF-DIAGNOSTIC SYSTEM

MALFUNCTION INDICATOR LIGHT (MIL) INSPECTION

Note. The Malfunction Indicator Light (MIL) on the instrument panel may also be referred to as CHECK ENGINE light. Inspect MIL to ensure it is operational and will come on if a DTC is stored.

1. Turn ignition on with engine off. MIL should come on and remain on. If MIL does not come on, check bulb circuit on instrument panel and wiring circuit between MIL and ECM. The ECM is located in the engine compartment behind the partition on the left side. See wiring diagram in the «WIRING DIAGRAMS»(ref-15435-S40931677462001010800000) section at the end of this article.
2. Start engine and ensure MIL goes off. If MIL remains on with engine running, a malfunction is detected. Proceed to «RETRIEVING DIAGNOSTIC TROUBLE CODES (DTC)»(ref-15435-S31167784412001010800000) .

TESTING & REPAIR PROCEDURE

The following check list of procedures is suggested to be followed to ensure correct diagnosis and repair

Retrieve Diagnostic Trouble Codes (DTC)

Connect appropriate scan tool. Retrieve DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTC) .

Visual Inspection

Inspect all connectors of suspect circuit or component. Ensure all connections are clean and tight.

Confirm Symptoms & DTCs

Perform road test. Determine if original symptoms are still present. Retrieve DTCs.

Diagnose & Repair DTCs

Perform diagnosis and repair procedures as needed. Refer to DIAGNOSTIC TESTING . If no codes are present, see the TESTS W/O CODES - 2.0L TURBO article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).

RETRIEVING DIAGNOSTIC TROUBLE CODES (DTC)

Note. MIL/DTCs (flash codes) should be used only for diagnosing faults. It is not absolutely certain that they indicate a faulty component.

DTC Retrieval (Without Scan Tool)

1. Access Data Link Connector (DLC). Carefully connect jumper wire between DLC terminal No. 2 and ground. (Схема №1)
2. Turn ignition on, engine off. The MIL will come on for about 6 seconds, go off, very briefly, then come on for about 3 seconds. This 3 second flash indicates that the DTC flash codes are about to begin.
3. The MIL will indicate any stored DTCs as a series of flashes denoting the single digit DTC. Flashes of.4 second duration will indicate the number of the DTC. Following a interval of 3 seconds, the next stored DTC will be indicated by another series of.4 second duration flashes.
4. If more than one DTC is stored, an interval of 2 seconds will separate the individual DTCs. After all stored DTCs have been retrieved, there will be a pause of about 3 seconds, then the DTCs will be repeated. The MIL will continue to flash any stored DTCs as long as DLC terminal No. 2 is grounded and ignition remains on. See the «MIL/DTC FLASH CODE IDENTIFICATION»(ref-15435-S00576275582001010800000) table.

MIL/DTC FLASH CODE IDENTIFICATION

DTC Retrieval (With Scan Tool)

Access Data Link Connector (DLC), under right front seat. Connect and operate scan tester in accordance with manufacturer's instructions. Turn ignition on. Turn on scan tool. Following scan tool instructions, retrieve any DTCs stored in memory. See the DTC CODES IDENTIFICATION table.

DTC CODES IDENTIFICATION

CLEARING DTC

Follow manufacturer's instructions to enter clear DTC(s) with scan tool. If scan tool is not available, DTCs may be cleared by unplugging ECM harness connector for a minimum of 5 minutes. This procedure will also erase ECM program. See PROGRAMMING ECM .

DIAGNOSTIC TESTING

Note. For component location information, refer to the THEORY/OPERATION - 2.0L TURBO article. The ISAT scan tool will be referred to simply as "scan tool".

Symptoms

Poor driveability, and MIL is on.

MIL is on.

Hard cold starting, poor driveability, and MIL is on.

Diagnosis & Repair Procedure

1. Connect scan tool to Data Link Connector (DLC). Start engine. Select READ FUNCTIONS. Select COOLANT TEMP. Check that scan tool readout indicates the approximate intake air temperature. If scan tool reading is incorrect, go to next step. If scan tool reading is correct, go to step 5). NOTE: In the event of an internal ECT sensor fault, scan tool will indicate 26°C. Replace ECT sensor and retest system.
2. Unplug the 2-pin ECT sensor connector. Measure specified values between indicated ECT sensor connector terminals and battery. See «ECT SENSOR CIRCUIT TEST»(ref-15435-S40068638632001010800000) table. (Схема №3) If all readings are as specified, go to next step. If all readings are not as specified, go to step 4). ECT SENSOR CIRCUIT TEST Terminals Approximate Value 1 & Battery (+) 12 Volts 2 & Battery (-) 5 Volts 1 & 2 1.8 Milliamps (mA)
3. Measure resistance of ECT sensor. See «SENSOR RANGE CHARTS - 2.0L TURBO»(ref-15467) article. If ECT sensor is good, go to next step. If ECT sensor does not test as specified, replace sensor and retest system.
4. Check wiring between ECT sensor connector and ECM for continuity and short circuits. See wiring diagram in «WIRING DIAGRAMS»(ref-15435-S40931677462001010800000) section. If wiring is good, go to next step. If any problems are found, repair circuit(s) as necessary.
5. Clear DTC(s) and road test vehicle. If DTC is reset, retest system. If DTC is not reset, repair is complete.

High idle speed, A/C inoperative, and MIL is on.

1. Connect scan tool to Data Link Connector (DLC). Start engine. Select READ FUNCTIONS. Select THROTTLE POSITION. If scan tool readout is about 10%, go to next step. If scan tool readout is about 2% or about 99%, go to step 5). NOTE: In the event of an internal TP sensor replacement, idle must be readjusted. See «ADJUSTMENTS - 2.0L TURBO»(ref-15425) article.
2. Depress the accelerator pedal very slowly, taking 20-30 seconds to achieve Wide Open Throttle (WOT). Observe scan tool during throttle advance. Readout should indicate a continuous, steady increase from 10% to 90%. Any break in the increase will cause a readout of 99% for a short time. If the scan tool readout is not as specified, go to next step. If the scan tool readout is as specified, go to step 5).
3. Unplug the 3-pin TP sensor connector. Measure specified values between indicated TP sensor connector terminals and battery. See «TP SENSOR CIRCUIT TEST»(ref-15435-S15827634612001010800000) table. (Схема №2) If all readings are not as specified, go to next step. If readings are as specified, go to step 5). TP SENSOR CIRCUIT TEST Terminals Approximate Value 1 & Battery (-) 5 Volts 3 & Battery (-) 5 Volts 2 & Battery (+) 12 Volts 2 & 3.1 Milliamps (mA)
4. Check wiring between TP sensor connector and ECM for continuity and short circuits. See wiring diagram in «WIRING DIAGRAMS»(ref-15435-S40931677462001010800000) section. If wiring is good, go to next step. If any problems are found, repair circuit(s) as necessary.
5. Clear DTC(s) and road test vehicle. If DTC is reset, retest system. If DTC is not reset, repair is complete.

MIL is on.

MIL is on.

Driveability problems, rough idle, and MIL is on.

1. Connect scan tool to Data Link Connector (DLC). Retrieve all stored DTCs. If DTC(s) P0105, P0106, P0107 and/or P0108 are displayed, service those DTCs and retest system. If DTC(s) specified do not exist, go to next step.
2. If DTC(s) P0130, P0131 and/or P0132 are displayed, service those DTCs and retest system. If DTC(s) specified do not exist, go to next step.
3. Check hose for air leaks between MAP sensor and the intake manifold. Check for air leak between fuel pressure regulator and intake manifold. If no leak(s) is found, go to next step. If leak(s) is found, repair as necessary. Retest system.
4. Test operation of MAP sensor. See DTC P0105, P0106, P0107 AND/OR P0108 diagnostic test procedure. If MAP sensor or circuit(s) are good, go to next step. If MAP sensor or circuit(s) are faulty, repair or replace as necessary.
5. Ensure exhaust system has no air leaks between engine and HO2S. If no problem is found, go to next step. If any problem(s) exists, repair as necessary.
6. Check fuel pressure. See procedures in the «SYSTEM/COMPONENT TESTS - 2.0L TURBO»(ref-15426) article. If no problems are found, go to next step. If problems are found, repair as necessary and retest system.
7. Clear DTC(s) and road test vehicle. If DTC is reset, retest system. If DTC is not reset, repair is complete.

Driveability problems, retarded ignition timing, and MIL on.

MIL is on.

1. Connect scan tool to Data Link Connector (DLC). Start engine. Select ACTIVATE. Select EVAP VALVE. Valve should be activated for 10 seconds at a frequency of 8 Hz. If valve can be heard clicking, go to next step. If valve cannot be heard clicking, go to step 3).
2. Unplug EVAP purge valve connector. Measure resistance between purge EVAP valve terminals. If resistance is 23-29 ohms, go to step 6). If resistance is not as specified, replace EVAP purge valve. Retest system.
3. To check the power supply, connect a test light between EVAP purge valve harness connector terminals. Activate scan tool command EVAP VALVE. The test light should flash at a frequency of 10 Hz for 10 seconds. If the test light flashes as specified, replace EVAP purge valve and retest system. If the test light does not flash as specified, go to next step
4. Turn ignition on. Activate scan tool command EVAP VALVE. Measure voltage at EVAP purge valve harness connector terminal No. 2. (Схема №2) If battery voltage exists, go to next step. If battery volt age does not exist, check wiring for open circuit. See wiring diagram in «WIRING DIAGRAMS»(ref-15435-S40931677462001010800000) section.
5. Check for continuity or short circuit between EVAP purge valve harness connector terminal No. 2 and ECM connector terminal No. 27. (Схема №5)and (Схема №2). If wiring is good, go to next step. If wiring is faulty, repair as necessary and retest system.
6. Clear DTC and road test vehicle. If DTC is reset, retest system. If DTC is not reset, repair is complete.

ABS light may be on, SHIFT UP light inoperative, fuel shut-off in all gears.

Idle low, high or hunting. Idle is sensitive to load changes.

1. Start engine and operate at idle. Restrict airflow through IAC valve by clamping air hose with pliers. If engine speed is not reduced sharply, go to next step. If engine speed is reduced sharply, go to step 3).
2. Check for the following: Air leakage after throttle plates. Incorrect throttle adjustment. Faulty brake servo. EVAP purge valve stuck open. If problems are found, repair as necessary.
3. Turn ignition on, engine off. Unplug 2-pin IAC valve harness connector. Connect test light between IAC valve harness connector terminals. Connect scan tool to Data Link Connector (DLC). Start engine. Select IAC VALVE. Select ACTIVATE. The test light should come on and glow steadily for about 10 seconds. If the test light does not come on, go to next step. If test light comes on, go to step 6).
4. Measure resistance between IAC valve harness connector terminal No. 1 and ground. (Схема №3) Measure the resistance with the ignition turned on and the with the ignition turned off. If the resistance is not 5-15 ohms, go to next step. If resistance is 5-15 ohms, repair faulty Green/Red wire between IAC harness connector terminal No. 2 and crimped connector J67 located on engine. See wiring diagram in «WIRING DIAGRAMS»(ref-15435-S40931677462001010800000) section.
5. Check for continuity between IAC valve connector terminal No. 1 and ECM connector terminal No. 49. (Схема №3)and (Схема №5). If continuity does not exist, repair wiring as necessary. If continuity exists, replace ECM. Retest system after repair.
6. Measure resistance between IAC valve terminals. If resistance is 7.6-7.8 ohms, go to next step. If resistance is not 7.6-7.8 ohms, replace IAC valve and retest system.
7. Disconnect air hoses from IAC valve. Ensure IAC valve harness connector is properly connected. On scan tool, select IAC VALVE. Select ACTIVATE. System will be activated for about 10 seconds. Repeat activation if longer time is needed to complete test. Visually check for valve slide operation. If valve slide operates, go to next step. If slide does not operate, replace IAC valve and retest system.
8. Clear DTC(s), then road-test vehicle. If DTC(s) resets, replace ECM and retest system. If DTC(s) does not reset, repairs are complete.

MIL is on, various system functions may be affected according to nature of internal malfunction.

1. Clear DTC and road test vehicle. If DTC is reset, remove and check the following: Condition of connector and connector sleeves. ECM ground connection. ECM power connection. If no fault is found, go to next step. If fault is found, repair or replace as necessary.
2. Clear DTC and road test vehicle. If DTC is not reset, repair is complete. If DTC is reset, replace ECM and retest system.

Driveability may be affected.