Engine Controls - Tests W/codes - 2.2l Ford Probe I

INTRODUCTION

Ensure all steps in the BASIC TESTING article have been followed. If no faults were found while performing BASIC TESTING , proceed with self-diagnostics. If no service codes (and ONLY pass codes) are found during self-diagnostics, proceed to the TESTS W/O CODES article for diagnosis of intermittents or driveability symptoms.

DIAGNOSTIC FORMATS

The EEC system uses 3 diagnostic formats: DIAGNOSTIC ROUTINES, QUICK TESTS and CIRCUIT TESTS (TESTS A1 to D3). The DIAGNOSTIC ROUTINES format categorizes the problem by symptom and directs the technician to the most logical procedure. QUICK TEST procedures allow the technician to identify problem(s), and to retrieve and record service codes.

Note. Always start with the QUICK TEST procedures before attempting any CIRCUIT TESTS. The QUICK TEST procedures allow the technician to retrieve and identify any service codes which are used as a reference to find the correct CIRCUIT TEST.

The CIRCUIT TESTS give procedures for testing circuits, sensors and actuators. If a vehicle passes all QUICK TEST procedures, and there are no driveability symptoms or intermittent faults, the EEC system is okay.

SERVICE CODE DESCRIPTION

There are 2 types of service codes retrieved in the QUICK TEST procedures

1. Key On Engine Off (KOEO)
2. Key On Engine Running (KOER)

Codes may be cleared from the ECA memory after they have been recorded or repaired. See RETRIEVING & CLEARING CODES .

KOEO & KOER CODES (HARD FAULTS)

These codes indicate a hard fault that is actually present at the time of testing. These hard faults may cause the CHECK ENGINE or SERVICE ENGINE SOON light to come on and remain on until the fault is repaired. If KOEO or KOER codes are retrieved during the Self-Test, see SERVICE CODE REFERENCE CHART under HOW TO USE CIRCUIT TESTS for testing and repair.

INTERMITTENT FAULTS

These faults indicate a defect that may or may not be present at the time of testing. Some faults may illuminate the CHECK ENGINE or SERVICE ENGINE SOON light. If the fault does not reoccur, the code will continue to be stored in the ECA until erased.

Intermittent faults may be caused by sensor, connector or wiring related problems. See INTERMITTENTS in the H - "Engine Type" TESTS W/O CODES article. Service codes may be cleared from memory by the technician. See RETRIEVING & CLEARING CODES.

RETRIEVING & CLEARING CODES

Note. The EEC system will not display a PASS code.

RETRIEVING CODES

Service codes are retrieved from the EEC system through the Self-Test connector by using a Scan tool, analog volt/ohmmeter or the CHECK ENGINE light. The KOEO and KOER SELF-TESTS are used for this purpose. After these codes have been recorded or repaired, they may be cleared from the ECA memory.

All service codes are 2 digit numbers, which are generated one digit at a time. These codes indicate a current fault in the system. They must be serviced in the order in which they appear. Use the appropriate service code chart to find the correct CIRCUIT TEST.

If a Scan tool diagnostic tester is used, it will count the pulses and display them as a digital code. The SUPER STAR II tester will add a zero (0) to single digit codes. (Scheme 1)

Scheme 1

If an analog voltmeter or the CHECK ENGINE light is being used, pay careful attention to the length of the pauses between signals in order to read the codes correctly. The first digit in a service code will be indicated by 1.2 second signals separated by a 0.4 second pause. There is a 1.6 second pause between the first digit and second digit. The second digit is indicated by 0.4 second signals separated by 0.4 second pauses. There will be a 4 second pause between each service code.

CLEARING CODES

To clear trouble codes, run the KOEO SELF-TEST. Deactivate the Self-Test by disconnecting the jumper wire from the STI connector. Disconnect the negative (-) battery cable and depress the brake pedal for 5-10 seconds. The STI connector is located at the left rear of the engine compartment.

SELF-TEST CONNECTOR LOCATION

KOEO & KOER SELF-TEST CODES

All service codes are output by the ECA, one digit at a time. These codes indicate a current fault in the system. They should be serviced in the order in which they appear. Use the SERVICE CODE REFERENCE CHART to find the correct CIRCUIT TEST.

If a Scan tool is used, it will count the pulses and display them as a digital code. Codes are shown as voltage pulses (needle sweeps) on an analog Volt/Ohmmeter (VOM). If the CHECK ENGINE light is used, service codes will be displayed as flashes.

Pay careful attention to the length of the pauses to read the codes correctly. There will be a O.4 second pause between the number of sweeps or flashes indicating a digit and a 1.6 second pause between each digit in a code. There will be a 4 second pause between each code.

TEST EQUIPMENT

The following equipment is recommended to diagnose and test the EEC system. Some equipment is REQUIRED to perform tests. DO NOT attempt to test this system without proper equipment. Damage to vehicle components may result if improper equipment is used.

1. The Self-Test Automatic Read-Out (SUPER STAR II) diagnostic tester is recommended but not required. It is specially built for EEC systems and is used to display the 2-digit (numeric) service codes that are programmed into the control module. Aftermarket Scan tools are also available.
2. Analog Volt/Ohmmeter (VOM) with 0-20V DC range. This can be used, as an alternative to a diagnostic tester, to read codes only.
3. Digital Volt/Ohmmeter (DVOM) with minimum 10-megohm input impedance.
4. Breakout Box. This is a jumper wire assembly that connects between the vehicle harness and the ECA. The breakout box is required to perform certain tests on the system. Ford Motor Co. specifically states that back-probing will cause PERMANENT DAMAGE to the ECA connector. The test pin No. called out in CIRCUIT TESTS refers to test pin numbers on breakout box. Once the breakout box has been installed during a test sequence, it may remain connected for the remainder of that test unless otherwise specified. Aftermarket breakout boxes are available.
5. Vacuum gauge with 0-30 in. Hg range and resolution (units on scale) of 1 in. Hg.
6. Tachometer with 0-6000 RPM range, accuracy +/- 40 RPM, and a resolution of 20 RPM.
7. Vacuum pump with 0-30 in. Hg range.
8. Timing light.
9. Spark Tester (D81P-6666-A or ST-125). A modified side electrode spark plug IS NOT sufficient for these testing procedures.
10. Fuel Injection Pressure Gauge (T80L-9974-A).
11. 12-volt test light (non-powered type).
12. Jumper wire, about 15" long.

When servicing the EEC system, always refer to the DIAGNOSTIC ROUTINE charts and QUICK TESTS before using CIRCUIT TESTS. The DIAGNOSTIC ROUTINE charts identify specific problems and refer the technician to specific repair areas, QUICK TESTS or CIRCUIT TESTS.

The QUICK TEST procedure is designed to allow the technician to identify problems and retrieve service codes. The CIRCUIT TESTS give procedures for testing circuits and checking sensors and actuators. If a vehicle passes the QUICK TEST procedures and there are no driveability problems, the EEC system is okay. Problem exists somewhere other than the EEC system.

DESCRIPTION

The QUICK TEST diagnostic procedure is a functional test of the EEC system. It consists of 4 basic test steps

1. VISUAL CHECK & VEHICLE PREPARATION
2. EQUIPMENT HOOK-UP
3. KEY ON ENGINE OFF (KOEO) SELF-TEST
4. KEY ON ENGINE RUNNING (KOER) SELF-TEST

These basic steps must be carefully followed in sequence, otherwise misdiagnosis, or replacement of non-faulty components may result. The QUICK TEST procedures should be used only when you are directed here by the DIAGNOSTIC ROUTINE charts. Anytime a repair is made.

1. The negative (-) battery cable should be disconnected.
2. The brake pedal should be depressed for 5-10 seconds.
3. The Self-Test sequence should be repeated to ensure the repair was effective and no codes are present.

Note. Correct test results depend on the correct operation of non-EEC components and systems. All non-EEC problems in the engine, ignition or fuel system should be corrected before attempting to diagnose the EEC system.

VISUAL CHECK & VEHICLE PREPARATION

Before hooking up any equipment to diagnose the EEC system, make the following visual checks and perform the preparation procedures

1. Verify condition of air cleaner and air ducting.
2. Check all vacuum hoses for leaks, restrictions, and proper routing.
3. Check the EEC system wiring harness electrical connections for corrosion, bent or broken pins, loose wires or terminals, and proper routing.
4. Check the ECA, sensors and actuators for physical damage.
5. Check engine coolant level.
6. Perform all necessary safety precautions to prevent personal injury or vehicle damage.
7. Set parking brake and place shift lever in Park for automatic transmissions, and Neutral for manual transmissions. DO NOT move shift lever during test unless specifically directed to do so.
8. Turn off all lights and accessories. Ensure vehicle doors are closed when making voltage or resistance readings.
9. Start engine, and idle until upper radiator hose is hot and pressurized, and throttle is off fast idle. Check for leaks around exhaust manifold, exhaust gas oxygen sensor, and vacuum hose connections.
10. Turn ignition off. Service items as required, then go to EQUIPMENT HOOK-UP.

ANALOG VOLT/OHMMETER (VOM)

Turn ignition switch to OFF position. Connect a jumper wire from Self-Test connector STI terminal to ground. Set VOM at 0-20V DC range, and connect positive (+) lead of VOM to Self-Test connector STO terminal. Connect the negative (-) test lead to engine ground. (Scheme 2)

SUPER STAR II TESTER

Turn ignition switch to OFF position. Connect color coded adapter cable leads to diagnostic tester. Connect service adapter cables to vehicle Self-Test connectors. Ground the adapter cable. Slide switch to MECS position.

"CHECK ENGINE" MALFUNCTION INDICATOR LIGHT (MIL)

Connect a jumper wire between the STI connector and ground. (Scheme 2)

Scheme 2

KEY ON ENGINE OFF (KOEO) SELF-TEST

Note. The following items should be noted before beginning KOEO test procedure

1. DO NOT depress throttle during KOEO SELF-TEST.
2. When the ignition key is turned to the ON position, a 3-second series of signals will be displayed.
3. It may be necessary to repair non-electronic faults before running the QUICK TEST procedures.
4. If no codes are displayed or a 00 is displayed on the Scan tool, proceed to the KOER SELF-TEST.
5. If no codes are displayed and vehicle is a no start, or if a code is displayed but CHECK ENGINE light does not light prior to activating Self-Test, proceed to TEST D3.

TEST PROCEDURE

Turn ignition switch to OFF position. Ensure all procedures of PREPARATION & EQUIPMENT HOOK-UP have been followed. Engine should be at normal operating temperature.

Disconnect and reconnect the jumper wire from Self-Test Input (STI) pigtail to ground. Turn ignition on. Record displayed codes. Erase codes and repeat test procedure to ensure all codes are currently valid. Service only those codes which appear during the re-test. Refer to SERVICE CODE REFERENCE CHART to find the appropriate CIRCUIT TEST.

MALFUNCTION INDICATOR LIGHT (MIL)

Turn ignition switch to ON position. Connect a jumper wire between the STI connector and ground. (Scheme 2) Observe MIL light, and record pulses to determine codes stored.

Set center button in the TEST position. Turn ignition switch to ON position. Turn tester on. When activated, the tester should display 888 for 2 seconds. Release and reset button in the TEST position. After all codes are received, release center button. All codes received in tester memory may now be reviewed.

KEY ON ENGINE RUNNING (KOER) SELF-TEST

Note. The following items should be noted before beginning KOER test procedure

1. DO NOT depress throttle during KOER SELF-TEST.
2. Clear all codes before proceeding with this test.
3. Ensure a 00 pass code is displayed or no codes are present during the KOEO SELF-TEST before proceeding with this test.
4. If no codes are displayed and vehicle is a no start, or if a code is displayed but CHECK ENGINE light does not light prior to activating Self-Test, proceed to TEST D3.

1) Deactivate Self-Test. Ensure vehicle is at normal operating temperature. Start engine and run at 2000 RPM for 2 minutes to ensure EGO sensor is operating.

1) Set center button in the TEST position. Turn ignition switch to OFF position. Turn ignition on and wait 10 seconds. Start engine, and let it idle.

2) To activate Self-Test, release and reset button in the TEST position. Record all codes displayed. Refer to SERVICE CODE REFERENCE CHART to find the appropriate CIRCUIT TEST.

ANALOG VOLT/OHMMETER OR MALFUNCTION INDICATOR LIGHT

1) Jumper STI connector to ground. Turn ignition switch to OFF position. Turn ignition on and wait 10 seconds. Start engine, and let it idle.

2) Activate Self-Test by connecting STI jumper to ground. Record all codes displayed. Refer to SERVICE CODE REFERENCE CHART to find the appropriate CIRCUIT TEST.

HOW TO USE CIRCUIT TESTS

1) DO NOT perform any CIRCUIT TEST unless directed to do so by a QUICK TEST procedure. Ensure all non-EEC related faults are corrected. FOLLOW EACH TEST STEP IN ORDER UNTIL FAULT IS FOUND. DO NOT replace any part unless directed to do so. When more than one service code is received, start with the first code displayed.

2) CIRCUIT TESTS require that you prove the electrical circuits are okay before you replace sensors or any other components. Always test circuits for continuity between the sensor and the ECA. Test all circuits for shorts to power, opens, or shorts to ground. Voltage Reference (VREF) and Voltage Power (VPWR) circuits should be tested with KOEO or as specified in the specific CIRCUIT TESTS (TESTS A1 to D3).

3) DO NOT measure voltage or resistance at ECA or connect any test light, unless specified in testing procedure. DO NOT pierce wiring. If backprobing is specified, always backprobe harness side of connector, never the connector side. Isolate both ends of a circuit and turn key off whenever checking for shorts or continuity, unless specified.

4) Unless otherwise specified, an open circuit is defined as a circuit which has a resistance greater than 5 ohms. Disconnect solenoids and switches before checking circuit continuity or energizing solenoids.

5) A short is defined as any resistance to ground of less than 10,000 ohms, unless otherwise specified.

Note. In the following tests, circuits and illustrations are supplied courtesy of Ford Motor Co. Complete EEC system wiring diagrams may be found at the end of this article.

SERVICE CODE-TO-TEST MENU

SERVICE CODE REFERENCE CHART

Scheme 3

CIRCUIT TEST INFORMATION

Due to a lack of space on the menu screen, CIRCUIT TESTS titles have been renamed to TEST only, followed by a short description. For example: TEST A1 - IGNITION DIAGNOSTIC MONITOR (IDM), TEST A2 - CRANKSHAFT POSITION SENSOR (CPS), etc.

The abbreviations for wire colors used in the individual CIRCUIT TEST diagrams and/or identification tables are as follows

1. "BK" Black
2. "BR" Brown
3. "DB" Dark Blue
4. "DG" Dark Green
5. "GY" Gray
6. "GN" Green
7. "BL" Blue
8. "LB" Light Blue
9. "LG" Light Green
10. "N" Natural
11. "O" Orange
12. "PK" Pink
13. "P" Purple
14. "R" Red
15. "T" Tan
16. "W" White
17. "Y" Yellow

IDM Circuit & Connector Identification (Non-Turbo). Scheme 4

Note. Enter this test only when Code 01 is displayed during QUICK TEST procedures. This test is intended to diagnose only the following: spark (EEC controlled) and electrical circuits (PIP, ignition ground and VPWR).

IDM CIRCUIT PIN IDENTIFICATION

CHECKING SYSTEM INTEGRITY

Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step for non-turbo engines or step 5 for turbo engines.

Note. Non-turbo vehicle circuit testing begins at step 1. For circuit testing on turbo vehicles, go to step 5.

1) Checking Coil IDM To ECA Circuit (Non-Turbo Engines) Connect spark tester between coil secondary cable and ground. Crank engine. If spark is not present, go to step 2. If spark is present, connect test light between ignition coil IDM (Yellow/Blue wire) and PWR (Black/White wire). Crank engine. If test light flashes, replace ECA. If test light does not flash, repair IDM circuit.

2) Continuous IDM At Coil Disconnect coil connector. Connect test light between ignition coil IDM (Yellow/Blue wire) and PWR (Black/White wire). Crank engine. If test light does not flash, go to step 4. If test light flashes, measure voltage between ignition coil PWR wire and ground. If voltage is greater than 10 volts, replace coil. If not, repair PWR circuit.

3) Continuous IDM At Ignition Module Disconnect ignition module connector. Jumper PWR wire to connector. Ensure IDM wire is disconnected. Connect test light between ignition coil IDM (Yellow/Blue wire) and PWR (Black/White wire). Crank engine. If test light flashes, service IDM circuit between ignition module and coil. If test light does not flash, go to step 4.

4) Checking Power to Ignition Module Disconnect ignition module connector. Turn ignition on. Measure voltage between ignition module PWR terminal and ground. If voltage is greater than 10 volts, replace ignition module. If voltage is less than 10 volts, repair PWR circuit between ignition module and ignition switch.

IDM Circuit & Connector Identification (Turbo). Scheme 5

5) Checking Coil IDM To ECA Circuit (Turbo Engines) Connect spark tester between coil secondary cable and ground. Crank engine. If spark is not present, go to step 7. If spark is present, disconnect ignition module connector. Connect test light between VPWR (Red/Black wire) and SPOUT (Yellow/Black wire). Crank engine. If test light is on, check SPOUT wire for short to ground. If okay, replace ignition module.

6) If test light does not come on, turn ignition off. Disconnect the ECA connector and install Breakout Box. Check for continuity between Breakout Box test pin No. 36 and ignition module SPOUT terminal. If continuity is present, check SPOUT circuit for short circuit. If okay and no other codes are present, replace ECA. If continuity is not present, repair circuit between ignition module SPOUT terminal and ECA.

7) Continuous IDM At Coil Disconnect coil connector. Connect test light between ignition coil IDM (Blue/Red wire) and PWR (Black/White wire). Crank engine. If test light does not flash, go to step 8. If test light flashes, measure voltage between ignition coil PWR wire and ground. If voltage is greater than 10 volts, disconnect coil connector. Connect test light between PWR wire and coil ground wire. If light is on, replace coil. If not, repair coil ground wire.

8) Continuous IDM At Ignition Module Disconnect ignition module connector. Jumper PIP, SPOUT, VPWR, and GND wires to connector. Ensure IDM wire is disconnected. Connect test light between ignition module IDM (Yellow wire) and VPWR. Crank engine. If test light flashes, repair IDM circuit between ignition module and coil.

9) If test light does not flash, turn ignition on. Measure voltage between ignition module VPWR wire and ground. If voltage is less than 10 volts, repair VPWR circuit between ignition module and main relay. If voltage is greater than 10 volts, connect test light between ignition module VPWR wire and ignition module ground.

10) Checking Power to Ignition Module If test light does not come on, repair ignition module ground circuit. If test light is on, connect analog voltmeter between ignition module PIP wire and ground. Set voltmeter on 5-volt scale and crank engine. If voltmeter indicator pulses, go to step 12.

11) If voltmeter indicator does not pulse, turn ignition off and disconnect ECA. Install breakout box at ECA wire harness connector. Leave ECA disconnected. Check for continuity between Breakout Box PIP terminal and PIP terminal at ignition module. If continuity is present, service short in PIP wire and any remaining codes in ECA memory. If problem continues, replace ECA.

12) If voltmeter indicator did pulse in step 10, connect test light between ignition module VPWR wire and ignition module SPOUT wire. Crank engine. If light comes on, check ignition SPOUT wire for short to ground. If okay, replace ignition module.

13) If light does not come on, turn ignition off and disconnect ECA. Install Breakout Box at ECA wire harness connector. Leave ECA disconnected. Check for continuity between Breakout Box SPOUT terminal and SPOUT terminal at ignition module. If continuity is present, service short in SPOUT wire and any remaining codes in ECA memory. If problem continues, replace ECA. If continuity is not present, check wiring between ignition module SPOUT and ECA connector for wire for short or open circuit.

CPS Circuit & Connector Identification. Scheme 6

CPS CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when Code 02 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking Resistance of CPS Circuit Turn the key off, and install breakout box. Leave ECA disconnected. Set VOM on 1000-ohm scle. Measure resistance between test pins No. 42 and 56. If resistance is 210-260 ohms, go to step 4. If not, go to next step.

3) Checking Resistance of CPS Turn key off and disconnect CPS. set VOM on 1000-ohm scale. Measure resistance between terminals "A" (Blue wire) and "B" (White wire) at CPS connector. If resistance is 210-250 ohms, go to next step. If resistance is not 210-250 ohms, replace CPS.

4) Checking CPS Input Voltage Install breakout box to harness connector leaving ECA disconnected. Crank engine while measuring voltage between terminals "A" (Blue wire) and "B" (White wire) at CPS connector. Voltage should be 0.6-0.8 volt. If not, replace CPS. If voltages are 0.6-0.8 volt and problem still exists but no other problems can be found, replace ECA.

CID1 Circuit & Connector Identification. Scheme 7

Note. Enter this test only when Code 03 is displayed during QUICK TEST procedures or when directed here from another CIRCUIT TEST. This test is intended to diagnose only the following: CID1, CIDREF, VPWR, & distributor ground.

CID1 CIRCUIT PIN IDENTIFICATION

Note. The CID is incorporated with the Crankshaft Position Sensor (CPS), inside the distributor.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking CID1 Circuit Resistance Turn ignition off and install breakout box. Leave ECA disconnected. Set VOM on 1000-ohm scale. Check resistances between CID1 and CIDREF test pins. If resistance is 210-260 ohms, go to step 4. If not, go to next step.

3) Checking CID1 Sensor Resistance Turn key off and disconnect distributor connector. Set VOM on 1000-ohm scale. Measure resistance between CID1 and CIDREF terminals. If resistances is not 210-260 ohms, replace CID1 sensor. If resistances is 210-260 ohms, repair CID1 (Green wire) or CIDREF (White wire) circuit from distributor to ECA.

4) Checking CID1 Circuit Voltage Disconnect distributor harness connector. Measure voltage between CID1 (Green) and CIDREF (White) test pin while cranking engine. If voltage is 0.6-0.8 volt, circuit is okay. If not, replace CID1 sensor.

CID2 Circuit & Connector Identification. Scheme 8

Note. Enter this test only when Code 04 is displayed during QUICK TEST procedures or when directed here from another CIRCUIT TEST. This test is intended to diagnose only the following: CID1, CIDREF, VPWR, & distributor ground.

CID2 CIRCUIT PIN IDENTIFICATION

Note. The CID is incorporated with the Crankshaft Position Sensor (CPS), inside the distributor.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking CID1 Circuit Resistance Turn key off and install breakout box. Leave ECA disconnected. Set VOM on 1000-ohm scale. Check resistances between CID2 and CIDREF test pins. If resistance is 210-260 ohms, go to step 4. If not, go to next step.

3) Checking CID1 Sensor Resistance With key off, disconnect distributor connector. Set VOM on 1000-ohm scale. Measure resistance between CID2 and CIDREF terminals. If resistances is not 210-260 ohms, replace CID2 sensor. If resistances is 210-260 ohms, repair CID2 (Red) or CIDREF (White) circuit from distributor to ECA.

4) Checking CID2 Circuit Voltage Disconnect distributor harness connector. Measure voltage between CID2 and CIDREF test pin while cranking engine. If voltage is 0.6-0.8 volt, circuit is okay. If not, replace CID2 sensor.

KS Sensor Circuit & Connector Identification. Scheme 9

KCU & KS CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when a Code 05 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST. This test is intended to diagnose only circuits KCU and KS.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking KCU Voltage Install breakout box. With key on, measure voltage between test pins No. 24 and 39 (ground). Start engine and tap lightly on engine lifting "eye" bracket with a small hammer while varying engine speed between 2500 and 4000 RPM. Voltage should be 3.3-5.0 volts and decrease when engine is tapped with hammer. If not, go to next step.

3) Checking KCU Signal Disconnect KCU connector. With connector removed, attach jumper wires between GND, KS and VPWR terminals. Leave KCU wire disconnected. Measure voltage between KC unit KC terminal and ground. Start engine and tap lightly on engine lifting "eye" bracket with a small hammer while varying engine speed between 2500 and 4000 RPM. If voltage is 3.3-5.0 volts and decreases when engine is tapped with hammer, repair KC wire between KC unit and ECA. If not, go to next step.

4) Checking VPWR At KC Unit Disconnect KCU connector. Turn key on and measure voltage between KCU VPWR wire and ground. If voltage is greater than 10.0 volts, go to step 5. If voltage is less than 10.0 volts, go to TEST A6.

5) Checking KCU Ground Circuit Disconnect KCU connector. Turn key on and measure voltage between KCU KC wire and ground. If voltage is greater than 10.0 volts, go to step 6. If voltage is less than 10.0 volts, repair KCU GND wire.

6) Checking KC Circuit Disconnect KCU connector. Set VOM on AC scale. Turn ignition on. Measure AC voltage between KCU KS wire and ground. Tap lightly on engine lifting "eye" bracket with a small hammer. If voltage is more than .03 volts when engine is tapped with hammer, replace KCU. If NOT, go to next step.

7) Disconnect knock sensor connector. Set VOM on AC scale. Measure AC voltage between knock sensor KS wire and ground. Tap lightly on engine lifting "eye" bracket with a small hammer. If voltage is more than .03 volts when engine is tapped with hammer, repair KS wire to KC unit. If not, replace knock sensor.

Power Relay Circuit & Connector Identification. Scheme 10

CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when directed here from CIRCUIT TESTS. To prevent replacement of good components, note that the following non-EEC components may be faulty: ignition switch, alternator, battery cables, ground straps or voltage regulator. This test is intended to diagnose only the following: ECA, wiring harness circuits, and battery voltage.

1) Checking Battery Circuit Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary.

2) Check Battery Charge If no faults are found, check battery voltage and charge condition. Service if necessary and go to next step.

3) Power Check Turn ignition off and install breakout box. Turn ignition on. Measure voltage between the followings points

1. VPWR test pin and battery ground.
2. VPWR test pin and each ground test pin.
3. VPWR test pin and each ECA ground wire.

If all voltages are greater than 10 volts, go to TEST A3. If all voltages are not greater than 10 volts, go to next step.

4) Checking Relay Ground Circuit Turn ignition off. Locate ain power relay inside rectangular cover behind master cylinder reservoir. Disconnect main power relay 4-wire connector. Using jumper wire, attach BATT, PWR, and GND terminals to connector. Leave VPWR wire disconnected.

5) Turn ignition on. Measure voltage between main power relay VPWR terminal and ground. If voltage is more than 10 volts, repair VPWR circuit between main power relay and ECA. If not, measure voltage between main power relay BATT wire and ground.

6) If voltage is less than 10 volts, repair BATT circuit between main power relay and battery. If there are more than 10 volts, measure voltage between main power relay PWR wire and ground. If voltage is less than 10 volts, repair PWR circuit between main power relay and ignition switch.

7) If not, measure voltage between main power relay BATT wire and main power relay ground. If voltage is less than 10 volts, repair main power relay ground wire. If not, ground circuit is okay. Replace main power relay.

TEST A7 - REFERENCE VOLTAGE & SIGNAL RETURN

Note. You should perform this test when a check for VREF has failed in the sensor input CIRCUIT TEST.

Reference Voltage Circuit & Connector Identification. Scheme 11

CIRCUIT PIN IDENTIFICATION

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Voltage Check Disconnect throttle position sensor connector. Turn ignition on. Check voltage between Throttle Position Sensor VREF and SIGRTN wires. See CIRCUIT COLOR IDENTIFICATION . If voltage is 4-5 volts, circuit is okay. If voltage is 10-12 volts, repair short to battery. If voltage is zero volts, go to step 3.

CIRCUIT COLOR IDENTIFICATION

3) Turn ignition off and install breakout box. Remove ECA connector. Measure resistance between the ECA connector VREF pin and ECA connector pin terminal of the following circuits

1. TPS
2. EVP

On all except non-turbo MTX models, measure resistance between the ECA connector VMREF pin and VAF pin. If any resistance is greater than 5 ohms, repair circuits as necessary.

4) If any resistance is less than 5 ohms, turn ignition off and install breakout box. Remove ECA connector. Remove EVP, TPS and VAF connectors. Measure resistance between breakout box pin 26 and ground. If resistance is less than 10,000 ohms, repair short in VREF circuit.

5) If resistance is greater than 10,000 ohms, remove ECT, EVP, TPS and VAF connectors. Measure resistance between the ECA connector SIGRTN pin and SIGRTN terminal of the connector that were removed. Repair any circuit that has greater than 5 ohms.

6) If circuit has less than 5 ohms, measure voltage at ECA SIGRTN connector pin terminal. If less than one volt is present, circuit is okay. If not, repair circuit short to battery.

Vehicle Speed Sensor Circuits. Scheme 12

CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when Code 06 is displayed during QUICK TEST procedures. This test is intended to diagnose only vehicle speed sensor circuits.

Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

1) Checking VSS Input Signal With key off, install breakout box and leave ECA disconnected. Disconnect speedometer cable from transaxle. Measure continuity between VSS test pin and ground.

2) Rotate speedometer cable. Continuity should exist 4 times per speedometer cable revolution. If continuity is correct, VSS circuit is okay. If continuity is not correct, go to next step.

3) Disconnect VSS connector. With speedometer cable disconnected from transaxle, rotate speedometer cable. Measure continuity between speed sensor VSS terminal and ground terminal. Continuity should exist 4 times per speedometer cable revolution.

4) If continuity is correct and speedometer is working, repair VSS or GND circuit between VSS sensor and ECA. If continuity is not correct, and speedometer is working, replace instrument cluster.

5) If continuity is correct and speedometer is not working, check speedometer drive gear. If okay, repair VSS or GND circuit between VSS sensor and ECA. If continuity is not correct, and speedometer is not working, check speedometer cable. If okay, replace instrument cluster.

VAF Meter Circuits. Scheme 13

CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when a Code 08 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST. To avoid unnecessary use of diagnostic time, check for unmetered air leaks between VAF meter and throttle body. This test is intended to diagnose only VAF and VMREF circuits.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking VAF Meter Voltage Install breakout box. Turn key on. Measure voltage between VAF and SIGRTN test pins. Voltage should be as listed in VAF METER VOLTAGE VALUES . If not, go to step 3. If voltage is correct, measure voltage between VMREF and SIGRTN test pins. If voltage is 7-9 volts, circuit is okay. Fault is in another circuit or ECA. If voltage is not 7-9 volts, repair VMREF circuit between ECA and VAF meter.

VAF METER VOLTAGE VALUES

3) Checking Signal From VAF Meter Locate VAF meter measuring vane and remove connector. Connect SIGRTN, VMREF and VPWR to VAF using jumper wire. Leave VAF circuit open. Turn ignition on. Measure voltage between terminal VAF terminal and SIGRTN terminal. Voltage should be as listed in VAF METER VOLTAGE VALUES . If not, go to step 4. If voltage is correct, repair VAF circuit between ECA and VAF meter.

4) Checking VREF At VAF Meter Turn ignition off. Remove VAF meter connector. Turn ignition on. Measure voltage between VAF wire and SIGRTN wire. If voltage is 4.5-5.5 volts replace VAF meter. If not, go to TEST A7.

5) VAF Signal Without VMREF Locate VAF meter air door. Turn ignition off. Remove meter connector. Using jumper wire, attach SIGRTN and VPWR connector terminals to VAF meter. Leave VAF and VMREF circuits open. Turn ignition on. Measure voltage between VAF terminal and SIGRTN terminal on VAF meter. Voltage should be as listed in VAF METER VOLTAGE VALUES as flap is moved. If voltage is correct, repair VMREF circuit between ECA and VAF meter. If not, go to step 6.

6) SIGRTN/VPWR At VAF Meter Remove VAF meter connector. Turn ignition on. Measure voltage between VPWR terminal and SIGRTN terminal at VAF meter. If voltage is greater than 10 volts replace VAF meter. If voltage is less than 10 volts, go to TEST A7.

ECT Sensor Circuits. Scheme 14

CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when a Code 09 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST. To prevent unnecessary diagnosis, inspect coolant level, oil level, cooling fan, thermostat and airflow to radiator for obstruction prior to electronic testing.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking ECT Voltage Ensure engine is at operating emperature. With key off, install breakout box. Turn ignition on. Measure voltage between ECT and SIGRTN test pins. Compare voltage to specifications shown in ECT SENSOR SPECIFICATIONS . If voltage is within specification, ECT circuit is okay. Fault is in another circuit or ECA. If voltage is not within specification, go to step 3.

3) Checking ECT Resistance Ensure engine is at operating temperature. With key off, install breakout box. Measure resistance between ECT and SIGRTN test pins. Compare resistance to specifications shown in ECT SENSOR SPECIFICATIONS . If resistance is within specification, go to step 4. If resistance is not to specification, go to step 5.

ECT & VAT SENSORS

4) ECT Circuit Isolation Install breakout box. Leave ECA disconnected. Remove ECT connector. Check continuity between ECT and SIGRTN test pins. If continuity is present, repair circuit between ECT sensor and ECA. If continuity is not present, replace ECA.

5) ECT Sensor Resistance Disconnect ECT sensor. With key off, measure sensor resistance. Compare resistance to specifications shown in ECT SENSOR SPECIFICATIONS . If resistance is okay, repair circuit between ECT sensor and ECA. If resistance is not to specification, replace ECT sensor.

VAT Circuits. Scheme 15

CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when a Code 10 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST. Ambient temperature must be greater than 50°F (10°C) for this test.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking VAT Voltage Ensure engine is at operating temperature. With key off, install breakout box. Turn ignition on. Locate VAT sensor in VAF meter. Measure voltage between VAT and SIGRTN test pins. Compare voltage to specifications shown in VAT SENSOR VOLTAGE SPECIFICATIONS . If voltage is within specification, VAT circuit is okay. Fault is in another circuit or ECA. If voltage is not within specification, go to step 3.

VAT SENSOR VOLTAGE SPECIFICATIONS

3) Checking VAT Resistance - Ensure engine is at operating temperature. With ignition off and breakout box installed, measure resistance between VAT and SIGRTN test pins. Compare resistance to specifications shown in VAT SENSOR RESISTANCE SPECIFICATIONS . If resistance is within specification, go to step 4. If resistance is not to specification, go to step 5.

VAT SENSOR RESISTANCE SPECIFICATIONS

4) VAT Circuit Isolation With breakout box installed, leave ECA disconnected. Remove VAF meter connector. Measure resistance between VAT and SIGRTN test pins. If resistance is less than 5 ohms, repair VAT sensor circuit to VAF meter. If resistance is more than 5 ohms, replace ECA.

5) VAT Sensor Resistance Disconnect VAF meter connector. Locate VAT sensor in VAF meter. With key off, measure sensor resistance. Compare resistance to specifications shown in VAT SENSOR RESISTANCE SPECIFICATIONS . If resistance is okay, repair circuit between VAT sensor and ECA. If resistance is not to specification, replace VAT sensor.

Throttle Position Sensor (TPS) Circuits. Scheme 16

CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when a Code 12 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST. To prevent replacement of good components, note the following non-EEC components may be at fault: idle speed or throttle stop adjustments, binding throttle shaft or linkage, binding cruise control linkage.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking TPS Voltage Ensure engine is at operating temperature. With key off, install breakout box. Turn ignition on. Measure voltage between TPS and SIGRTN test pins. Slowly depress accelerator pedal and compare voltage to specifications shown in THROTTLE POSITION SENSOR SPECIFICATIONS . If voltage is within specification, TPS circuit is okay. Fault is in another circuit or ECA. If voltage is not within specification, go to step 3.

3) Checking TPS Signal Return Remove TPS connector. Turn ignition on. Using jumper wire, attach SIGRTN and VREF connector terminals to TPS sensor. Attach voltmeter between sensor TPS terminal and SIGRTN terminal. Slowly depress accelerator pedal and compare voltage to specifications shown in THROTTLE POSITION SENSOR SPECIFICATIONS . If resistance is within specification, repair TPS circuit between ECA and TPS. If resistance is not to specification, go to step 4.

4) Checking SIGRTN/VREF At TPS Remove TPS connector. Turn ignition on. Measure voltage between TPS wire and SIGRTN wire. If voltage is 4.5-5.5 volts replace TPS. If not, go to TEST A7.

THROTTLE POSITION SENSOR SPECIFICATIONS

TEST B6 - BAROMETRIC PRESSURE SENSOR

Note. Enter this procedure only when a Code 14 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST. To prevent unnecessary replacement of components, note that the following non-EEC items may be at fault: unusually high or low atmospheric barometer reading, blocked vacuum lines and basic mechanical engine components.

Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, erase codes from memory. Perform KOEO and KOER SELF-TESTS. If code 14 continues to appear, replace ECA.

Note. The barometric pressure sensor is built into the ECA and cannot be replace separately. If code 14 is given and cannot be erased, ECA must be replaced.

TEST C1 - EXHAUST GAS/OXYGEN (EGO) SENSOR

EGO CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when a code 15 (lean) or code 17 (rich) is displayed during the QUICK TEST procedure.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking EGO Sensor Output Voltage Warm engine to operating temperature and let idle. Disconnect EGO sensor. Set VOM on 5-volt scale. Measure voltage between EGO sensor connector (sensor side) and ground. With engine at idle, voltage should be 0.2-0.8 volts.

3) Rapidly decrease and increase engine speed while reading voltmeter. When engine speed is decreasing, voltage should decrease. When engine speed is increasing, voltage should increase. If voltage is within specification, go to next step. If voltage is not to specification, replace EGO sensor.

4) Isolating Open Circuit In EGO Sensor With key off, install breakout box. Leave ECA disconnected. Disconnect EGO sensor connector. Measure continuity between EGO test pin and all other test pins. If EGO is shorted to any other circuit, repair as necessary. If circuit is okay, fault is in another circuit or ECA.

EVP Sensor Circuit. Scheme 17

EVP CIRCUIT PIN IDENTIFICATION

Note. Enter this test only when a Code 16 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST.

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking EGR Voltage Ensure engine is at operating emperature. With key off, install breakout box. Attach voltmeter to EVP and SIGRTN test pins. Turn ignition on. Install vacuum pump to EGR vacuum port. Slowly apply vacuum to EGR VALVE. Compare voltage to specifications shown in EGR SENSOR SPECIFICATIONS . If voltage is within specification, EVP circuit is okay. Fault is in another circuit or ECA. If voltage is not within specification, go to step 3.

3) Checking EGR Signal Return Remove EVP sensor connector. Using jumper wire, attach connector VREF (Green/Red) and SIGRTN (Green/Yellow) wire back to EVP sensor. Install vacuum pump to EGR vacuum port. Attach voltmeter to EVP and SIGRTN terminal on EVP sensor. Turn ignition on. Slowly apply vacuum to EGR VALVE.

4) Checking SIGRTN/VREF At EGR Compare voltage to specifications shown in EGR SENSOR SPECIFICATIONS . If voltage is within specification, repair EVP circuit between sensor and ECA. If voltage is not to specification, measure voltage between connector VREF wire and SIGRTN wire. Turn ignition on. If voltage is 4.5-5.5 volts replace EVP sensor. If not, go to TEST A7.

EGR SENSOR SPECIFICATIONS

PRC Sensor Circuit. Scheme 18

Note. Enter this test only when a Code 25 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST.

PRC CIRCUIT PIN IDENTIFICATION

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking Solenoid Function Install breakout box and leave ECA disconnected. Turn ignition on. Apply vacuum to fuel pressure regulator. Vacuum should hold. Jumper breakout box PRC test pin to ground. See PRC CIRCUIT PIN IDENTIFICATION . If vacuum releases, solenoid is functioning okay. Fault is in another circuit or ECA. If vacuum is held, go to step 3.

3) Check Voltage To PRC Solenoid Disconnect PRC solenoid connector. With ignition on, measure voltage between VPWR (Red/Black) wire and ground. If voltage reading is less than 10 volts, repair VPWR (Red/Black) wire to fuel pump relay. If voltage reading is than 10 volts, go to step 4.

4) Warm to operating temperature. Turn engine off. Measure voltage between solenoid VPWR and PRC (White/Black) wire while cranking engine. Replace solenoid if voltage is more than 10 volts. If voltage is less than 10 volts, go to next step.

5) PRC Circuit Continuity Check With breakout box installed and ECA disconnected, remove solenoid connector. Check for continuity between breakout box pin and connector terminal. See PRC CIRCUIT PIN IDENTIFICATION . If continuity does not exist, repair wire between solenoid connector and ECA.

6) If continuity is present, check for continuity between PRC breakout box pin and all other test pins. If continuity is found between PRC test pin and another test pin(s), PRC wire is shorted to that circuit. Repair as necessary and recheck circuit. If all circuits are okay, replace ECA.

Probe 2.2L Turbo Fuel Delivery System. Scheme 19

TEST C4 - CANISTER PURGE (CANP)

Note. Enter this test only when a Code 26 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST.

CANP Circuit & Connector Identification. Scheme 20

CANP CIRCUIT PIN IDENTIFICATION

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking Solenoid Function Install breakout box and leave ECA disconnected. Turn ignition on. Remove canister purge hose from intake manifold and apply vacuum. Jumper CANP test terminal to ground. If vacuum releases, solenoid is functioning okay. Fault is in another circuit or ECA. If not, go to step 3.

3) Check Voltage To CANP Solenoid Disconnect solenoid connector. With ignition on, measure voltage between VPWR and ground. If voltage reading is less than 10 volts, repair VPWR wire to fuel pump relay. If not, measure voltage between solenoid VPWR and CANP wire (ignition on).

4) Activate solenoid by operating vehicle in cruise or acceleration mode. Replace solenoid if voltage is more than 10 volts, when activated. If voltage is less than 10 volts, go to next step.

5) CANP Circuit Continuity Check With breakout box installed and ECA disconnected, remove CANP solenoid connector. Check for continuity between CANP test pin and CANP solenoid wire. If continuity does not exist, repair CANP circuit between solenoid and ECA.

6) If continuity is present, check for continuity between CANP test pin and all other test pins. If continuity is found between CANP test pin and another test pins, CANP wire is shorted to that circuit. Repair as necessary and recheck circuit. If all circuits are okay, replace ECA.

EGR Control & EGR Vent Circuit & Connector Identification. Scheme 21

Note. Enter this test only when a Code 28 (EGRC) or Code 29 (EGRV) is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST.

EGRC & EGRV CIRCUIT PIN IDENTIFICATION

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking Solenoid Function Install breakout box and leave ECA disconnected. Turn ignition on. Apply vacuum to EGR valve. Vacuum should not hold. Apply vacuum to EGR valve again. Jumper breakout box test pin terminal (EVRC or EVRV) to ground. If vacuum is held, solenoid is functioning okay. Fault is in another circuit or ECA. If not, go to step 3.

3) Voltage To Solenoid Check Disconnect solenoid connector. With ignition on, measure voltage between VPWR and ground. If voltage reading is less than 10 volts, repair VPWR wire to main relay. If voltage reading is more than 10 volts, measure voltage between solenoid VPWR and EGRC or EGRV wire (ignition on).

4) Activate solenoid by operating vehicle in cruise (EGRC) or wide open throttle (EGRV) mode. Replace solenoid if voltage is more than 10 volts, when activated. If voltage is less than 10 volts, go to next step.

5) EGRC/EGRV Circuit Continuity Check With breakout box installed and ECA disconnected, remove solenoid connector. Check for continuity between EGRC/EGRV test pin and EGRC/EGRV solenoid wire. If continuity does not exist, repair EGRC/EGRV circuit between solenoid and ECA.

6) If continuity is present, check for continuity between EGRC/EGRV test pin and all other test pins. If continuity is found between EGRC/EGRV test pin and another test pin(s), EGRC/EGRV wire is shorted to that circuit. Repair as necessary and recheck circuit. If all circuits are okay, replace ECA.

TEST C6 - EGR VACUUM RELEASE (EVR) SOLENOID

Note. Enter this test only when a Code 28 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST.

EVR Circuit & Connector Identification. Scheme 22

EVR CIRCUIT PIN IDENTIFICATION

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking Solenoid Function Install breakout box and leave ECA disconnected. Turn ignition on. Apply vacuum to EGR valve. Vacuum should hold. Apply vacuum to EGR valve again. Jumper breakout box EVR test pin to ground. If vacuum is held, EVR solenoid is functioning okay. Fault is in another circuit or ECA. If not, go to step 3.

3) Check Voltage To EVR Solenoid Locate EVR solenoid mounted on left side cowl panel. Disconnect solenoid connector. With ignition on, measure voltage between VPWR (Red/Black) wire and ground. If voltage reading is less than 10 volts, repair VPWR (Red/Black) wire to main relay. If not, start engine and warm to operating temperature.

4) Measure voltage between solenoid VPWR and EVR (White/Black) wire. With engine below 1500 RPM, solenoid should be activated. Replace solenoid if voltage is more than 10 volts, when activated. If voltage is less than 10 volts, go to next step.

5) EVR Circuit Continuity Check With breakout box installed and ECA disconnected, remove solenoid connector. Check for continuity between breakout box pin No. 33 and EVR connector (White/Black) wire. If continuity does not exist, repair EVR (White/Black) wire between solenoid and ECA.

6) If continuity is present, check for continuity between breakout box pin No. 33 and all other test pins. If continuity is found between EVR test pin and another test pin(s), EVR wire is shorted to that circuit. Repair as necessary and recheck circuit. If all circuits are okay, replace ECA.

TEST D1 - IDLE SPEED CONTROL (ISC)

Note. Enter this test only when a Code 34 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST.

ISC Circuit & Connector Identification. Scheme 23

ISC CIRCUIT PIN IDENTIFICATION

1) Checking System Integrity Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking Solenoid Function Install breakout box and leave ECA disconnected. Turn ignition on. Jumper breakout box test pin No. 41 to ground. Listen for clicking sound at solenoid. If clicking sound is heard, ISC solenoid is functioning okay. Fault is in another circuit or ECA. If not, go to step 3.

3) Check Voltage To ISC Solenoid Locate ISC solenoid mounted on throttle body. Disconnect solenoid connector. With ignition on, measure voltage between VPWR (Red/Black) wire and ground. If voltage reading is less than 10 volts, repair VPWR wire to main relay. If voltage reading is more than 10 volts, GO TO STEP 4.

4) Warm to operating temperature. Turn engine off. Measure voltage between ISC solenoid VPWR and ISC (White/Black) wire while cranking engine. Replace solenoid if voltage is more than 10 volts. If voltage is less than 10 volts, go to next step.

5) ISC Circuit Continuity Check With breakout box installed and ECA disconnected, remove solenoid connector. Check for continuity between breakout box pin No. 41 and ISC connector (White) wire. If continuity does not exist, repair ISC (White) wire between solenoid and ECA.

6) If continuity is present, check for continuity between breakout box pin No. 41 and all other test pins. If continuity is found between breakout box pin No. 41 and another test pin(s), ISC wire is shorted to that circuit. Repair as necessary and recheck circuit. If all circuits are okay, replace ECA.

TEST D2 - TURBOCHARGER BOOST CONTROL SOLENOID (BOOST)

Note. Enter this test only when a Code 42 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST.

BOOST Solenoid Circuit & Connector Identification. Scheme 24

BOOST CIRCUIT PIN IDENTIFICATION

1) Checking System Integrity Visually check all wiring, harness connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking Solenoid Function Install breakout box and leave ECA disconnected. Turn ignition on. Locate boost solenoid mounted on lower side of turbocharger. Apply vacuum to boost solenoid. Vacuum should hold. Jumper breakout box test pin No. 31 to ground. If vacuum is held, solenoid is functioning okay. Fault is in another circuit or ECA. If not, go to step 3.

3) Check Voltage To Boost Control Solenoid Disconnect solenoid connector. With ignition on, measure voltage between VPWR and ground. If voltage reading is less than 10 volts, repair VPWR wire to main relay. If voltage reading is more than 10 volts, measure voltage between solenoid VPWR and BOOST wire (ignition on).

4) Activate solenoid by quickly increasing engine speed above 4500 RPM. Replace solenoid if voltage is more than 10 volts, when activated. If voltage is less than 10 volts, go to next step.

5) Circuit Continuity Check With breakout box installed and ECA disconnected, remove BOOST solenoid connector. Check for continuity between BOOST test pin and BOOST solenoid wire. If continuity does not exist, repair BOOST circuit between solenoid and ECA.

6) If continuity is present, check for continuity between BOOST test pin and all other test pins. If continuity is found between BOOST test pin and another test pins, BOOST wire is shorted to that circuit. Repair as necessary and recheck circuit. If all circuits are okay, replace ECA.

SELF TEST INPUT (STI)

Note. Enter this test only when Star Tester displays STO LO or VOM displays zero volts.

STI CIRCUIT PIN IDENTIFICATION

1) Checking System Integrity Visually check all wiring and connectors for evidence of damage, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Install breakout box and leave ECA disconnected. Connect test light between STI test pin and 12 volt source. If light does not comes on, repair circuit between STI connector and ECA. If light does come on, go to SELF TEST OUTPUT (STO).

SELF TEST OUTPUT (STO)

Note. Enter this test only when codes cannot be retrieved or when directed by SELF TEST INPUT (STI).

STO Connector Identification. Scheme 25

STO CIRCUIT PIN IDENTIFICATION

1) Checking System Integrity Visually check all wiring and connectors for evidence of damage, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Install breakout box and leave ECA disconnected. Check for continuity between STO test pin and STO diagnostic connector terminal. If continuity is not present, repair circuit between ECA and STO diagnostic connector. If continuity is present, go to step 3.

3) Check for continuity between the STO test pin and all other test pins. If continuity is present between the STO test pin and any other test pin, circuit is shorted. Repair as necessary. If not, return to H - "Engine Type" TESTS W/O CODES article in this section.

2.2L Probe Main Fuse Assembly System Wiring Diagram. Scheme 26

2.2L (Auto. Trans.) EEC System Wiring Diagram. Scheme 27

2.2L (Man. Trans.) EEC System Wiring Diagram. Scheme 28

2.2L Turbo EEC System Wiring Diagram. Scheme 29

If more information is necessary, see the appropriate chassis wiring diagram in WIRING DIAGRAMS section.

See also:
• RETRIEVING & CLEARING CODES
• SERVICE CODE REFERENCE CHART