Home ReviewsRefund
Home/Volvo/960/Volvo 960 I рестайлинг (1994-1997)/Repair manual/Testing & Diagnostics/Engine Controls - Tests W/codes: Other
Contents Section: Testing & Diagnostics All sections

Engine Controls - Tests W/codes: Other Volvo 960 I рестайлинг

Testing & Diagnostics 2 illustrations ~1884 words

RETRIEVING CODES

CAUTIONNever disconnect or connect ECU connector with ignition switch in ON position. Ensure ignition is off and fuse No. 24 is removed.

ECU is equipped with diagnostic functions in form of self-diagnostics (Test Mode No. 1), function testing (Test Mode No. 2) and control testing (Test Mode No. 3). Access to diagnostic system is provided by socket No. 2 on diagnostic unit with ignition on.

CLEARING CODES

  1. Turn ignition on. Display fault codes. Operate test button for more than 5 seconds. Release test button. LED should light after 3 seconds. Press button again for more than 5 seconds. Release button. LED should be out.
  2. Ensure fault codes have been cleared by pressing test button once for more than one second (but not more than 3 seconds). Fault codes have been cleared if code 1-1-1 is displayed.

FAULT CODE DEFINITION

CodeFaultRepair
1-1-1No FaultsNone
1-1-2ECUReplace ECU
1-1-3Fuel InjectorsCheck Fuel Injectors
1-2-1Mass Airflow Signal(1) Check Airflow Meter & Main Relay
1-2-3Coolant Temp. Sensor Signal(1) Check Sensor
1-3-1Timing Pick-Up Signal(2)
1-3-2Battery Voltage(2)
1-4-3No Front Knock Sensor Signal(2)
2-1-2Oxygen Sensor Signal(1) Check Oxygen Sensor
2-1-4Timing Pick-Up Signal(2)
2-2-3No Idle Valve Signal(2)
2-3-1Lambda Rich/Lean In Part-Load Range(2)
2-3-2Lambda Rich/Lean At Idle(2)
2-3-3Idle Control Not In Range(2)
2-4-1EGR Flow Too Low(2)
2-4-3Throttle Switch Signal Absent Or Faulty(2)
3-1-1Speedometer Signal(2)
3-1-4Camshaft Sensor Signal(2)
3-2-2Airflow Meter Hot Wire(2)
4-3-1EGR Temp Sensor Absent/Faulty(2)
4-3-3No Rear Knock Sensor Signal(2)
5-1-2Short Term Fuel Trim(2)
(1) See the SYSTEM/COMPONENT TESTS article. (2) See FAULT CODE TESTING under SELF-DIAGNOSTIC SYSTEM.
(1)See the SYSTEM/COMPONENT TESTS article.
(2)See FAULT CODE TESTING under SELF-DIAGNOSTIC SYSTEM.

FAULT CODES

CONNECTING MEASURING UNIT TO ECU

Note. Measuring unit may also be known breakout box.

CAUTIONWhile connecting and disconnecting adapter, ECU must not have live voltage as it could be damaged.

Connect measuring unit. Turn ignition off. Remove fuse No. 1 (11B/1) in central relay unit. Disconnect ECM. Connect measuring unit to ECU connector.

Scheme 8

Scheme 8
Scheme 8

CODE 1-3-1 OR 2-1-4: TIMING PICK-UP SIGNAL

  1. Enter test mode No. 2. See TEST MODE NO. 2 under «RETRIEVING CODES»(ref-15250-S02490740322000122900000) . Operate starter motor. Code 1-4-1, indicating a timing pick-up signal, should be displayed.
  2. Disconnect ECU connector. Connect a voltmeter capable of measuring millivolts between ECU connector terminals No. 47 (Pink wire) and No. 48 (White/Black wire). Operate starter motor. Voltmeter should indicate 300-400 millivolts.
  3. Turn ignition off. Connect an ohmmeter between timing pick-up connector terminals No. 47 (Pink wire) and No. 48 (White/Black wire). Resistance should be about 200-400 ohms.
  4. Reconnect ECU with Measuring Unit (999-3070 ) connected to ECU. See «CONNECTING MEASURING UNIT TO ECU»(ref-15250-S10153784032004021300000) . Connect an ohmmeter between measuring unit terminals No. 48 and 19. Resistance should be zero ohms. Measure resistance between terminals No. 48 and 30. Resistance should be zero ohms. On automatic transmission equipped vehicles, check test mode No. 1 if speed signal fault code is displayed. See TEST MODE NO. 1 under «RETRIEVING CODES»(ref-15250-S02490740322000122900000) .

CODE 1-3-2: BATTERY VOLTAGE

  1. This code is set if battery voltage decreases to less than 8 volts or exceeds 16 volts for 5 seconds after engine start. To check, connect Measuring Unit (999-3070 ) to ECU. See «CONNECTING MEASURING UNIT TO ECU»(ref-15250-S10153784032004021300000) . Connect voltmeter between measuring unit terminals No. 18 and 19.
  2. Start engine and check battery voltage. Check battery and charging system if voltage is too low or high.

CODE 1-4-3 OR 4-3-3: NO FRONT/REAR KNOCK SENSOR SIGNAL

Disconnect knock sensor connector and jumper terminals. Measure resistance between knock sensor terminal No. 2 (Green/Gray wire) and terminal No. 11 (Green wire) or terminal No. 29 (Brown/Orange wire), depending upon whether front or rear knock sensor is being checked. If zero ohms is present, replace knock sensor. Tighten sensor to 15 ft. lbs. (20 N.m).

CODE 2-2-3: NO IDLE VALVE SIGNAL

  1. Check operation of idle valve in test mode No. 3. See TEST MODE NO. 3 under «RETRIEVING CODES»(ref-15250-S02490740322000122900000) . If valve does not operate, check wiring.
  2. Connect Measuring Unit (999-3070 ) to ECU. See «CONNECTING MEASURING UNIT TO ECU»(ref-15250-S10153784032004021300000) . Start engine. Connect voltmeter between measuring unit terminals No. 4 and 24. About 11 volts should be present. Connect voltmeter between measuring unit terminals No. 22 and 24. About 7.5 volts should be present.
  3. Turn engine off (ignition on). Using a voltmeter, check voltage at measuring unit terminals No. 4 and 22. Voltage should be about 8-9 volts. If no voltage is present, check wiring to idle valve.
  4. Turn ignition off. Using an ohmmeter, check resistance across measuring unit terminals No. 4 and 22. Resistance should be about 25 ohms. If not, replace idle valve.

CODE 2-3-1: LAMBDA CONTROL RICH OR LEAN IN PART-LOAD RANGE, CODE 2-3-2: LAMBDA CONTROL RICH OR LEAN AT IDLE

  1. Control unit receives information from oxygen sensor on whether fuel/air mixture is too rich or too lean in part-load and idling ranges. Control unit adaptive system compensates for this by making mixture leaner or richer as necessary. If mixture must be compensated excessively, a fault code is set.
  2. Start engine. Connect voltmeter between terminals No. 1 and 2 in starter motor 2-pin connector. Voltmeter should indicate battery voltage. If no voltage is present, check fuse No. 30.
  3. Stop engine. Disconnect starter motor connector. Connect ohmmeter between starter motor connector terminals No. 1 and 2. Ohmmeter should show 3-13 ohms, depending on resistor temperature.
  4. Connect Measuring Unit (999-3070 ) to ECU. See «CONNECTING MEASURING UNIT TO ECU»(ref-15250-S10153784032004021300000) . Start engine. Connect voltmeter between measuring unit terminals No. 28 and 30. After a short interval, voltmeter should oscillate between 0.1-1.0 volt.
  5. If voltage remains constant at zero volts, sensor is interpreting fuel/air mixture as lean. If voltage is constant at one volt, sensor is interpreting fuel/air mixture as rich.
  6. If either fault code 2-3-1 or 2-3-2 is displayed and voltmeter is oscillating between 0.1-1.0 volt, Lambda control is correctly adjusting CO content even though ECU is indicating fault.

CODE 2-3-3: IDLE CONTROL NOT IN RANGE

  1. If control unit has to open or close idling valve too much to maintain constant idling conditions, control unit will interpret this as a fault and record a fault code.
  2. Start engine and run it until it reaches normal operating temperature. Ensure gear selector is in Neutral and A/C is off. To determine whether an air leak is present, clamp air valve hose and observe engine speed. If engine speed exceeds 600-700 RPM, air leakage is present or throttle disc is incorrectly adjusted.

CODE 2-4-1: EGR FLOW TOO LOW

  1. Enter test mode No. 3. See TEST MODE NO. 3 under «RETRIEVING CODES»(ref-15250-S02490740322000122900000). Turn ignition on. Press test button on diagnostic unit 3 times for more than one second each. Light should flash as EGR converter is activated. Turn ignition off.
  2. If EGR converter is not activated, measure resistance between pins No. 6 (Blue wire) and No. 15 (Red/Green wire). Resistance should be about 75-95 ohms. If resistance is not as specified, check wiring and connectors.
  3. Disconnect EGR converter connector, located next to power steering fluid reservoir. (Scheme 9) Remove wire directly opposite Black/White wire between pin No. 1 and control unit. Reconnect connector.
  4. Start engine and run it until it reaches normal operating temperature. Touch loose lead to engine ground. If engine starts to run unevenly, EGR system is operating correctly.

Scheme 9

Scheme 9
Scheme 9

CODE 2-4-3: THROTTLE SWITCH SIGNAL ABSENT OR FAULTY

  1. Enter test mode No. 2. See TEST MODE NO. 2 under «RETRIEVING CODES»(ref-15250-S02490740322000122900000) . Turn throttle slightly. Throttle function is correct in idling position if flashing code 3-3-2 is displayed.
  2. Turn throttle to full-load position and release. Throttle function is correct in full-load position if flashing code 3-3-3 is displayed.
  3. Connect Measuring Unit (999-3070 ) to ECU. See «CONNECTING MEASURING UNIT TO ECU»(ref-15250-S10153784032004021300000) . Turn ignition on. Connect voltmeter between measuring unit terminals No. 30 and 53. Voltmeter should indicate about 0.5 volts at idle and about 4.5 volts at full load.
  4. Connect voltmeter between measuring unit terminals No. 12 and 30. Voltmeter should indicate 5 volts. Turn ignition off. Ensure measuring unit terminal No. 30 is grounded. Connect an ohmmeter between measuring unit terminals No. 19 and 30. Ohmmeter should indicate zero ohms.

CODE 3-1-1: SPEEDOMETER SIGNAL

  1. Control unit is dependent on this signal for WOT enrichment, fan control, etc. A fault code will be set if speed exceeds 3390 RPM, load signal corresponds to part load and signal is absent for 3 seconds.
  2. To check speedometer signal, raise vehicle with rear wheels suspended. Connect Measuring Unit (999-3070 ) to ECU. See «CONNECTING MEASURING UNIT TO ECU»(ref-15250-S10153784032004021300000) . Connect voltmeter between measuring unit terminals No. 9 and 19. Turn ignition on. Spin rear wheels and check voltmeter. Voltage should be 0.1-12.0 volts.
  3. If voltage is not present, check wiring between control unit and instrument cluster. Connect ohmmeter between measuring unit terminal No. 9 and terminal at rear of instrument cluster (Green/Orange wire). Ohmmeter should indicate zero ohms.
  4. If no reading is obtained, check wiring between instrument cluster and control unit. If reading is obtained, check wiring between instrument cluster and rear axle. On A/T models, check test mode No. 1 if speed signal fault is obtained. See TEST MODE NO. 1 under «RETRIEVING CODES»(ref-15250-S02490740322000122900000) .

CODE 3-1-4: CAMSHAFT SENSOR SIGNAL

  1. Camshaft sensor enables control unit to determine which cylinder requires fuel and ignition. A fault code is recorded if signal remains constantly high or low for more than 30 seconds.
  2. To check camshaft sensor signal, remove fuse No. 31 to prevent engine from starting and connect Measuring Unit (999-3070 ) to ECU. See «CONNECTING MEASURING UNIT TO ECU»(ref-15250-S10153784032004021300000) . Turn ignition switch to ON position. Connect voltmeter across measuring unit terminals No. 8 and 19. Operate starter motor. Voltage should oscillate between .1 and .5 volt. Install fuse No. 31.
  3. If signal is absent or faulty, ensure voltage across measuring unit terminals No. 10 and 30 is about 11 volts. Turn ignition off. Ensure measuring unit terminal No. 30 is grounded. Connect an ohmmeter between measuring unit terminals No. 30 and 19. Ohmmeter should indicate zero ohms.

CODE 3-2-2: AIRFLOW METER HOT WIRE

  1. About 4 volts is routed to platinum wire in airflow meter from ECU terminal No. 5. Ground is supplied from ECU terminal No. 7. Fault code is set if voltage between ground and terminal No. 7 does not exceed 2.5 volts.
  2. Turn ignition off. Connect Measuring Unit (999-3070 ) to ECU. See «CONNECTING MEASURING UNIT TO ECU»(ref-15250-S10153784032004021300000) . To ensure airflow meter is grounded, connect ohmmeter between measuring unit terminals No. 19 and 26. Zero ohms should be present. Connect ohmmeter between airflow meter connector terminal No. 1 (Brown wire) and ground. Reading should be about zero ohms.
  3. Connect ohmmeter between measuring unit terminals No. 7 and 26. Reading should be about 2.5-4.0 ohms. If resistance is not to specification, measure resistance between airflow meter terminals No. 2 (Brown/White wire) and No. 3 (Green/Yellow wire).
  4. Turn ignition on. Connect voltmeter between measuring unit terminals No. 7 and 19. About 1.4 volts should be present. Start engine. Voltage should increase to 2.3-2.6 volts when idling. Voltage should be 2.3 volts with engine hot.
  5. If voltage reading is too low, connect voltmeter between measuring unit terminals No. 25 and 19. Increase speed to 1800 RPM and stop engine. Voltage should be about 4 volts. On A/T models, check test mode No. 1 if load signal fault code is displayed. See TEST MODE NO. 1 under «RETRIEVING CODES»(ref-15250-S02490740322000122900000) .

CODE 4-3-1: EGR TEMPERATURE SENSOR ABSENT/FAULTY

Measure resistance between terminals No. 14 (Black wire) and No. 22 (Yellow/Black wire). Resistance should be 500-1000 ohms. If resistance is not 500-1000 ohms, check wiring, connectors and ground terminal on intake manifold.

Fault Condition

The ECM receives information from the HO2S on air/fuel mixture. If air/fuel mixture deviates from l=1, the short-term fuel trim compensates for it by adjusting the injection period. If the short-term fuel trim remains lean for more than 3 minutes and engine temperature exceeds 75°C (167°F), DTC 5-1-2 is set.

Substitute Value

None is provided.

Possible Sources

Faulty sensor signal or high fuel pressure.

SUMMARY

If no hard fault codes (or only pass codes) are present, driveability symptoms exist or intermittent codes exist, proceed to the TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.

More articles — Engine Controls - Tests W/codes