Tests W/codes - Carbureted Ford Festiva I

INTRODUCTION

If no faults were found while performing BASIC TESTING , proceed with self-diagnostics. If no fault codes or only pass codes are present, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.).

HARD FAILURES

Hard failures cause "malfunction" light to illuminate and remain on until the malfunction is repaired. If light comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined using diagnostic (code) charts. If a sensor fails, control unit will use a substitute value in its calculations to continue engine operation. In this condition, vehicle is functional, but loss of good driveability will most likely be encountered.

INTERMITTENT FAILURES

Intermittent failures may cause "malfunction" light to flicker or illuminate and go out after the intermittent fault goes away. The corresponding trouble code, however, will be retained in control unit memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from control unit memory. Intermittent failures may be caused by sensor, connector or wiring related problems. See INTERMITTENTS in TESTS W/O CODES article.

RETRIEVING CODES

The EFC system is capable of detecting malfunctions, and storing and outputting fault codes for diagnostic purposes. ECA has built-in fail-safe functions which will control engine function during periods of failure.

To access fault codes, a special Tester (007-00028) is used. If codes are detected, install EEC-IV Breakout Box (014-00322) and Adaptor (007-00027) to diagnose system. If a special tester is not available, an analog voltmeter can be used to read fault codes.

READING FAULT CODES WITH ANALOG VOLTMETER

1) Ground one-pin check connector B-14 (Yellow/Blue wire terminal).

2) Connect analog voltmeter positive lead to Green/Red wire terminal of 6-pin self-test connector under dash. Connect voltmeter negative lead to ground.

3) Diagnostic codes may be read by observing voltmeter needle long and short pulses.

4) Codes are indicated by a 2-digit number. Long pulses indicate first digit. Short pulses indicate second digit. If zero is the first digit, no long pulses will be indicated and needle sweeps will begin with short pulses. A short pause will occur between codes. (Scheme 31)

MALFUNCTION INDICATOR LIGHT (MIL)

Malfunction indicator light comes on whenever an emissions related fault occurs. The fault warning light should go out after repairing fault in vehicle.

CLEARING CODES

A fault code will remain in ECA memory until erased. To erase memory, disconnect negative battery cable and depress brake pedal for at least 5 seconds. Reconnect battery cable and ensure malfunction indicator light is off.

SUMMARY

If no hard fault codes are displayed, proceed to TESTS W/O CODES article diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.), or intermittent diagnosis procedures. Also see I - SYS/COMP TESTS article.

Scheme 31

FAULT CODE/TEST MENU

ECA FAULT CODES-TO-TESTS MENU

ECA2, CODE 01 - IGN PULSE

1) Check for loose connectors, corrosion or damage at ignition coil negative terminal and ECA terminal 1M. Repair as necessary.

2) With key on and engine off, check voltage at terminal 1M at ECA. Voltage should read 12-14 volts. If voltage reading is correct, replace ECA.

3) If voltage reading is incorrect, check for short in White wire from coil negative terminal to terminal 1M of ECA. If symptom still persists, go to ECA55.

ECA 4, CODE 09 - COOLANT TEMPERATURE SENSOR (CTS) CIRCUIT

1) Check for loose connectors, corrosion or damage at coolant temperature sensor and ECA terminal 2I. Repair as necessary.

2) Check resistance across temperature sensor terminals. Resistance should be as shown in COOLANT TEMPERATURE SENSOR RESISTANCE . If resistance is incorrect, replace temperature sensor.

COOLANT TEMPERATURE SENSOR RESISTANCE

3) If resistance is within specification, turn ignition on and check for voltage at ECA terminal 2I. If voltage reading is 5 volts, check for open in wire between temperature sensor Brown/Red terminal and ECA terminal 2I. Repair as necessary.

4) If voltage reading is 0-2.5 volts, check for short in wire between temperature sensor Brown/Red terminal and ECA terminal 2I. Repair as necessary.

5) If no short is indicated, go to ECA 8. If symptom persists, go to ECA55.

ECA8, CODE 13 - MAP SENSOR

1) Check for loose connectors, corrosion or damage at MAP sensor and ECA terminals 2E and 2A. Repair as necessary.

2) Check for 12 volts at Black/White wire at MAP sensor connector. If 12-volt signal is not present, check for open in wire between ignition switch and MAP sensor. Repair as necessary.

3) Check voltage at MAP sensor Light Green wire terminal. Voltage reading should be about 5 volts. If 5-volt signal is not present, check for open or short in wire between MAP sensor and ECA terminal 2A. If no problem is found, replace ECA.

4) With engine warm and idling, check voltage at MAP sensor Brown/Black terminal. Voltage reading should be .8-1.5 volts. If voltage is not within specification, replace MAP sensor.

5) Check continuity of wiring from MAP sensor to ECA. Repair or replace as necessary. If symptom persists after repairs are made, go to ECA55.

6) Check wiring for shorts from MAP sensor Black terminal to ECA terminal 2C and from MAP sensor Black/Brown terminal to ECA terminal 2E. Repair as necessary. If no problems are found, replace ECA.

ECA14, CODE 15 - EGO SENSOR

1) Run engine at 2500 RPM for one minute. Recheck code. If code is no longer in memory, problem is intermittent.

2) If code is still stored, check for air leaks. Repair as necessary.

3) Check for fouled spark plugs. Clean and replace as necessary.

4) Connect voltmeter between EGO sensor connector and ground. Run engine at 4000 RPM until .55 volt is indicated. Increase and decrease engine speed quickly. Note voltage.

5) Speeds greater than 4000 RPM should produce a .5-1.0-volt signal. Decreased speed should produce a voltage of 0-0.4 volt. If voltage signal is not within specification, replace EGO sensor.

6) Check voltage at ECA terminal 2D. With key on and engine off, reading should be zero volts. With engine at idle, reading should be .05 volt. With engine running above 2000 RPM, voltage should read .2-.7 volt.

7) If voltage is incorrect, check for open or short in wiring between EGO sensor and ECA terminal 2D. Repair as necessary. If symptom persists, go to ECA55. If voltage is correct, replace ECA.

ECA19, CODE 16 - EGR VALVE POSITION (EGRVP) SENSOR

1) Check for loose connectors, corrosion or damage at EVP sensor and ECA terminals 2F and 2C. Repair as necessary.

2) Check resistance from Light Green wire terminal to Black wire terminal. Resistance should measure 4500-5500 ohms. Check resistance from Light Green wire terminal to Light Green/Black wire terminal. Resistance should measure 0-5500 ohms.

3) If resistance is not within specification, replace EVP sensor. If resistance is within specification, check EGR valve operation before continuing with diagnosis.

4) Check voltage at Light Green wire terminal to EVP sensor. If voltage reading is not about 5 volts, check for open or short in wiring between EVP sensor Light Green wire terminal and ECA terminal 2A. If no problem is found in wiring, replace ECA.

5) Check continuity between EVP sensor and ECA. Check continuity between Light Green/Black wire and ECA terminal 2F. Check continuity between Black EVP sensor wire and ECA terminal 2C. Check for shorts in same wires. If wiring is okay, replace ECA.

6) If continuity does not exist in wires, repair or replace as necessary. If symptom persists, go to ECA55.

ECA 23, CODE 17 - FEEDBACK (FDBK) SYSTEM

1) Run engine at 2500 RPM for one minute and recheck code. If code is no longer in memory, problem is intermittent.

2) If code is still stored, check for intake air leaks. Repair as necessary.

3) Check for fouled spark plugs. Clean and replace as necessary.

4) Connect voltmeter between EGO sensor connector and ground. Run engine at 4000 RPM until .55 volt is indicated. Increase and decrease engine speed quickly. Note voltage.

5) Speeds greater than 4000 RPM should produce a .5-1.0-volt signal. Decreased speed should produce a voltage of 0-.4 volt. If voltage reading is not within specification, replace EGO sensor.

6) Check voltage at ECA terminal 2D. With key on and engine off, reading should be zero volts. With engine at idle, reading should be .5 volt. With engine running above 2000 RPM, voltage should read .2-.7 volt.

7) If voltage is incorrect, check for open or short in wiring between EGO sensor and ECA terminal 2D. Repair as necessary. If symptom persists, go to ECA55. If voltage is correct, replace ECA.

ECA28, CODES 18, 19, 20 & 21 - AIR BLEED CONTROL VALVE (ABCV)

1) Check for loose connectors, corrosion or damage at ABCV and ECA terminals 3C, 3E, 3F and 3H. Repair as necessary.

2) Check ABCV resistance. If resistance is not within specification, replace ABCV.

AIR BLEED CONTROL VALVE (ABCV) RESISTANCE

3) Check for continuity between ABCV terminals and ECA. If continuity does not exist, check for open in wiring between ECA and ABCV. Repair as necessary. If symptom still persists, go to ECA55.

4) If continuity exists, check for shorts in wiring between ECA and ABCV. If no problem is found in wiring, replace ECA.

ABCV-TO-ECA CONTINUITY CHECK

ECA 31, CODE 22 - FUEL SHUTOFF SOLENOID

1) Check for loose connectors, corrosion or damage at fuel shutoff solenoid and ECA terminals. Repair as necessary.

2) Check for continuity across Black/White and Red/White wire terminals at fuel shutoff solenoid. If continuity does not exist, replace fuel shutoff solenoid.

3) Turn ignition on. Check for battery voltage at Black/White wire terminal of fuel shutoff solenoid valve. If voltage is not present, check for open or short in solenoid Black/White wire to ignition switch.

4) Check for continuity between solenoid Red/White wire and ECA terminal 2P. If continuity exists, check for short in wiring from solenoid to ECA. If short does not exist, replace ECA.

5) If continuity does not exist, check for open in wiring from solenoid to ECA. Repair as necessary. If symptom still persists, go to ECA55.

ECA 35, CODES 28 & 29 - EGR SOLENOID VALVE

1) Check for loose connectors, corrosion or damage at EGR solenoid valves and ECA terminals 2N and 2M. Repair as necessary.

2) Check continuity across EGR solenoid valve terminals. If continuity is not within specification, replace defective valve(s).

EGR SOLENOID VALVE CONTINUITY CHECK

3) Check for battery voltage at Black/White wire of each solenoid valve. If battery voltage is not present, check for open or short between EGR solenoid valve(s) and ignition switch. Repair as necessary.

4) Check continuity of wiring between EGR solenoid valves and ECA. If code 28 was stored in memory, check Brown wire from No. 1 solenoid valve to ECA terminal 2N. If code 29 was stored in memory, check No. 2 solenoid valve Brown/White wire to ECA terminal 2M.

5) If continuity exists between solenoid valves and ECA, check for short in wiring between ECA and solenoid valves. If no problem is found in wiring, replace ECA.

6) If continuity does not exist between EGR solenoid valves and ECA, check for open in wiring between EGR solenoid valve(s) and ECA. Repair or replace as necessary. If symptoms persist, go to ECA55.

ECA 39, CODE 31 - AIR CONTROL VALVE

1) Check for loose connectors, corrosion or damage at ACV and ECA terminal 2R. Repair as necessary.

2) Check continuity across terminals of ACV. If continuity does not exist, replace ACV.

3) Check for battery voltage at Black/White wire terminal of ACV. If voltage is not present, check for open or short in wiring between ACV and ignition switch. Repair as necessary.

4) Check continuity between ACV Yellow/Blue wire terminal and ECA terminal 2R. If continuity does not exist between ACV and ECA, check for open in wiring between ACV and ECA. Repair as necessary. If symptom persists, see ECA55.

5) If continuity exists between ACV Yellow/Blue wire terminal and ECA terminal 2R, check for short in wiring between ACV and ECA. If no problem is found in wiring, replace ECA.

ECA 43, CODES 34 & 35 - IDLE-UP SYSTEM

1) Check for loose connectors, corrosion or damage at idle-up solenoid valves and ECA terminals 1C and 2K. Repair as necessary.

2) Check for continuity across terminals of idle-up solenoid valves. If code 34 was set in memory, check continuity of Electrical Load (E/L) solenoid Black/White wire terminal to Light Green/Red wire terminal. If code 35 was set in memory, check continuity of A/C solenoid Black/White wire terminal to Blue/Yellow wire terminal. If continuity does not exist, replace defective solenoid(s).

3) Check for battery voltage on Black/White wire terminals of A/C and E/L solenoid. If voltage is not present, check for short or open in wiring between idle-up solenoid valves and ignition switch. Repair as necessary.

4) Check for continuity between idle-up solenoids and ECA. (Scheme 32) Check continuity between E/L solenoid Light Green/Red wire terminal and ECA terminal 1C. Check continuity between A/C solenoid Blue/Yellow wire terminal and ECA terminal 2K.

5) If continuity does not exist, check for open in wiring between idle-up solenoids and ECA. Repair as necessary. If symptom persists, go to ECA55.

6) If continuity exists, check for shorts in wiring between idle-up solenoids and ECA. If no problem is found in wiring, replace ECA.

Scheme 32

ECA 47, CODE 38 - EFE HEATER RELAY

1) Check for loose connectors, corrosion or damage at EFE heater relay and ECA terminal 2Q. Repair as necessary.

2) Check for continuity between EFE heater relay Black/White and Black/Red wire terminals. If continuity does not exist, replace EFE heater relay.

3) Check EFE heater relay Black/White lead for battery voltage. If battery voltage is not present, check for open or short in wiring between EFE heater relay and ignition switch.

4) Check for continuity between EFE heater relay Black/Red wire terminal and ECA terminal 2Q. If continuity does not exist, check for open in wiring between EFE heater relay and ECA. Repair as necessary. If symptom persists, go to ECA55.

5) If continuity does exist, check for short in wiring between EFE heater relay and ECA. If no problem is found in wiring, replace ECA.

ECA 51, CODE 70 - VACUUM SWITCH

1) Check for loose connectors, corrosion or damage at vacuum switch and ECA terminal 2J. Repair as necessary.

2) Apply vacuum to vacuum switch and test for continuity across switch terminals. (Scheme 33) If continuity does not exist, replace vacuum switch. Continuity should exist with as little as 2.36 in. Hg applied.

3) Check for continuity between vacuum switch Black wire and ground. If continuity does not exist, repair ground circuit.

4) Check for continuity between vacuum switch Blue/Black wire terminal and ECA terminal 2J. If continuity does not exist, check for open in wiring between vacuum switch and ECA. Repair as required. If symptom persists, go to ECA55.

5) If continuity does exist, check for short in wiring between vacuum switch and ECA. If no problem is found in wiring, replace ECA.

Scheme 33

ECA 55, NO CODE - KEEP ALIVE POWER

1) With key off, check for 12 volts at ECA terminal 3J. If battery voltage is not present, check for open or short in wiring between battery positive terminal and ECA terminal 3J. Repair as necessary.

2) With key on, check for 12 volts at ECA terminal 3J. If 12 volts is not present, check ignition switch for proper operation. Repair or replace as necessary.

See also:
• COOLANT TEMPERATURE SENSOR RESISTANCE