Cruise Control System Ford LTD Crown Victoria I

VISUAL INSPECTION

Visual inspection is an important part of the system diagnosis, and should be performed before undertaking any of the following diagnostic procedures.

When performing a visual inspection, check all items for abnormal conditions such as bare, broken or disconnected wires and damaged vacuum hoses. For the speed control system to function properly, it is necessary that the speedometer cables if so equipped be properly routed and securely attached. All vacuum hoses must be securely attached and routed with no sharp bends or kinks. The servo (throttle actuator), and throttle linkage should operate freely and smoothly.

The actuator cable should be adjusted as tight as possible without opening the throttle plate or increasing the idle speed. Electrical connections must be complete and tight. The wiring harness must be properly routed. Look for damaged wire insulation or evidence of shorts.

Any problem revealed by the visual inspection should be corrected before further tests of the speed control system are made.

ELECTRONIC INSTRUMENT CLUSTER

AC and DC voltage measurements required in diagnosis of speed control on vehicles with an electronic instrument cluster require the use of a Beckman model 3020, Fluke model 8022A, or an equivalent voltmeter.

The speed signal is provided by the electronic speedometer rather than the speed sensor. DO NOT perform the speed sensor test on vehicles equipped with the electronic speedometer. Rather connect an AC voltage across the Circuit 150 DG/W and ground leads at the amplifier. (Scheme 1) With the wheels raised and the vehicle speed at 30 mph, the AC voltmeter should read approximately 6-24 volts.

Refer to ELECTRONIC INSTRUMENT CLUSTER SPEED DIAGNOSIS CHART (Test Steps K1 through K4).

Speed Control Amplifier. Scheme 1

Speed Sensor Test. Scheme 2

The Integrated Vehicle Speed Control (IVSC) contains a self-test capability.

Key On, Engine Off (KOEO) and Key On, Engine Running (KOER) routines output error codes in a manner similar to EEC-IV subsystem "Quick Test", which then refer to Pinpoint Tests for specific component diagnosis.

The Rotunda Speed Control Automatic System Tester 007-00013 or equivalent cannot be used for IVSC diagnosis. The Rotunda Self-Test Automatic Readout (STAR) Tester 007-00017, Super STAR Tester 007-00019, or Analog volt-ohmmeter (VOM) 059-00010 or equivalent, 0-20 VDC (alternate to STAR) is required to perform the IVSC Quick Test and display error codes.

A Rotunda Breakout box 014-00322 or equivalent can also be used for convenience during Pinpoint Testing.

Testing for the IVSC is divided into two formats: the Quick Test and Pinpoint Tests. The Quick Test is a functional IVSC system test. The Pinpoint Tests are specific component tests.

The Quick Test checks all IVSC components except the speed sensor, which must be tested separately. To test and service the IVSC system, perform the Quick Test first. If the system passes, check the speed sensor. If failure codes are generated, perform only the Pinpoint Test specified by that particular failure code.

After all test and services have been completed, repeat the entire Quick Test to verify that the IVSC system operates properly.

Quick Test

The Quick Test is a functional test of the IVSC system consisting of basic Test Steps (described below). These steps must be carefully followed in sequence. Otherwise, incorrect diagnosis or the replacement of undamaged components may result.

1. Visual Check and Preparation: Check for obvious faults Properly prepares the vehicle for testing.
2. Equipment hookup ensures that the proper equipment for gathering test data is ready prior to testing.
3. Key On, Engine Off Self Test is a static check of IVSC inputs and outputs.
4. Key On, Engine Running Self Test is a dynamic check for the IVSC with engine in operation.

Visual Check and Vehicle Preparation

Correct test results for the Quick Test are dependent on the proper operation of related non-IVSC component systems. It may be necessary to correct faults in these areas before the IVSC will pass the Quick Test.

Before hooking up any equipment to diagnose the IVSC system, make the following checks

1. Check all engine vacuum hoses for leaks or pinched hoses (servo to dump valve and servo to manifold vacuum).
2. Check the IVSC and EEC system wiring harness electrical connections for proper connections, loose or detached connectors, wires and terminals, corrosion and proper routing of harness. It may be necessary to disconnect or disassemble the connector assembly to perform some of the inspections. Note the location of each pin before assembly.
3. Check the EEC-IV ECA and IVSC sensors and actuators for physical damage.
4. Perform all safety steps required to start and run operation vehicle tests.
5. Apply the emergency brake. Place the shift lever in PARK.
6. Turn off all electrical loads such as the radio, lamps, air condition, etc. Ensure doors are closed whenever readings are made.
7. Verify engine coolant is at the specified level.
8. Start the engine and idle until the upper radiator hose is hot and pressurized and the throttle is off fast idle.
9. Turn the ignition switch to the OFF position.
10. Service items as required, and proceed to equipment hookup.

Equipment Hookup (Using STAR tester 007-00019 or 007-00017 or equivalent.

Turn the ignition switch to the OFF position. Connect the color-coded adapter cable leads to the STAR tester. Connect the adapter cable's two service connectors to the vehicle's appropriate self-test connectors. After equipment hookup, go on to Self-Testing.

Using Analog Voltmeter 059-00010 or equivalent.

Turn ignition switch to OFF position. Connect a jumper wire from self-test input (STI) to Pin 2, signal return on the self-test connector. Set analog VOM on a DC voltage range to read from 0-15 volts DC. Connect VOM from battery (+) to Pin 4 self-test output (STO), in the self-test connector. After equipment hookup, go on to Self-Testing.

Quick Test Self-Test

Quick Test Self Testing is divided into two specialized tests: Key On, Engine Off, and Key On, Engine Running. The self-test is not a conclusive test by itself, but is used as a part of the functional Quick Test diagnostic procedure. The processor stores the Self-Test program in its permanent memory. When activated, it checks the IVSC system by testing its functional capability and verifies that various sensors and actuators are connected and operating properly.

The Key On, Engine Off and Engine Running tests are functional tests which only detect fault codes present at the time of the Self-Test.

Key On, Engine Off Test

At this time, a test of the IVSC system is conducted with power applied and engine at rest.

The fault must be present at the time of testing for errors to be detected in this test.

Key On, Engine Running Test

At this time, a test of the IVSC system is conducted with power applied and engine at running. The system is checked under actual operating conditions and at normal operating temperatures. The actuators are exercised and checked for corresponding results.

Service Codes

The EEC-IV system communicates service information through the Self Test service codes. These service codes are two digit numbers representing the results of the Self-Test.

The service codes are transmitted on the self-test output (found in the self-test connector) in the form of timed pulses, and read by the technician on a voltmeter or on the STAR tester.

Equipment Hookup. Scheme 3

Self-Test Output Code Format. Scheme 4

Reading Codes - Analog Voltmeter

When a service code is reported on the analog voltmeter for a function test, it will represent itself as a pulsing or sweeping movement of the voltmeter's needle across the dial face of the voltmeter. Therefore, a single-digit number of three will be reported by three needle pulses (sweeps). However, as previously stated, a service code is represented by a two-digit number, such as 2-3 will appear on the voltmeter as two needle pulses (sweeps). After a two-second pause, the needle will pulse (sweep) three times.

Reading Codes - Rotunda Self-Test Automatic Readout (STAR) Tester 007-00017, or Super STAR Tester 007-00019 or Equivalent

After hooking up the STAR tester and turning on its power switch, the tester will run a display check and the numerals 88 will begin to flash in the display window. A steady 00 will then appear to signify that the STAR tester is ready to start the Self Test and receive the test's service codes.

To receive the service codes, press the push button at the front of the STAR tester. The button will latch down, and a colon will appear in the display window in front of the 00 numerals. The colon must be displayed to receive the service codes.

If for any reason the technician wishes to clear the display window during the Self Test, he must turn off vehicle's engine, press the tester's push buttons once to unlatch it (colon will disappear), then press the button again to latch down the button (colon will appear again). Every time the STAR tester is turned off, the low battery indicator (LO BAT) should show briefly at the upper LH corner of the tester's display window. If the LO BAT indicator shows steadily at any other timer during the operation of the STAR tester with any service code, turn its power switch to OFF and replace the 9-volt battery in the tester.

The STAR tester will display the last service code received, even after it has been disconnected from the vehicle. It will hold the service code on the display until the power is turned off or the push button is unlatched and relatched.

QUICK TEST: KEY ON, ENGINE OFF (KOEO) SELF TEST

To Activate the KOEO IVSC Test, do the following

1. Place transmission shift lever in PARK.
2. Leave single STI connector unplugged; plug in multi-pin self- test connector.
3. Turn on STAR tester by moving slide switch to ON position.
4. Press STAR push button.
5. Turn ignition key to RUN position.
6. Within 10 seconds, press speed control ON switch
7. Observe code 10 OFF, COAST, ACCEL, RESUME buttons; tap brake pedal once. DO NOT depress throttle during KOEO self-test.
8. Observe and record all Service Codes indicated. One of the following outputs will occur.

If Code 11 is Displayed

KEY ON, ENGINE OFF TEST indicates a pass. GO To KEY ON, ENGINE RUNNING (KOER) SELF TEST.

Any other code(s)

KEY ON, ENGINE OFF TEST indicates a fault. Record codes and GO TO STEP B.

No Codes Outputted

Repeat SELF-TEST and verify that no service codes are present. GO To Pinpoint Test Step Q1.

1. Using the KEY ON, ENGINE OFF service codes from Step A follow the steps below.
2. When more than one service code is received always start with the first code received.
3. Whenever a service is made REPEAT QUICK TEST.

Note. Before proceeding to the specified Pinpoint Test, read the instructions on how to use the Pinpoint Test at the beginning of the Pinpoint Section.

QUICK TEST (A, B, C): KEY ON, ENGINE OFF SELF-TEST (1)

QUICK TEST: KEY ON, ENGINE RUNNING (KOER) SELF TEST

Before running KOER Self Test, start the engine and idle until the upper radiator hose is hot and pressurized, with the throttle off fast idle and the idle stabilized, then shut engine off.

To Activate the KOER Self Test do the following

1. Connect STAR self-test and STI connectors.
2. Start engine, turn on STAR tester by moving slide switch to ON position.
3. Within 30 seconds of starting engine, press speed control ON switch.
4. Within 15 seconds press STAR push button.
5. Observe code 10 on STAR display (indicates IVSC test in progress).
6. Observe and record all Service Codes indicated. One of the following outputs will occur.

Note. DO NOT depress throttle or brake pedal during KOER Self-Test. This procedure must be followed exactly to obtain IVSC KOER Self-Test.

Note. The engine may stall at test exit. Turn off the ignition to prevent entry into EEC-IV Key On, Engine Off Self-Test.

ENGINE RUNNING SELF TEST indicates a pass. If the drive symptom is currently present GO To DIAGNOSTIC BY SYMPTOM. Otherwise testing is complete, IVSC system is OK.

ENGINE RUNNING SELF TEST indicates a fault. GO TO STEP B.

Repeat SELF-TEST and verify that no service codes are present. GO To Pinpoint Test Step Q1.]

1. Using the ENGINE RUNNING service codes from Step A follow the steps below.
2. When more than one service code is received always start with the first code received.
3. Whenever a service is made REPEAT QUICK TEST.

QUICK TEST (D, E, F): KEY ON, ENGINE OFF SELF-TEST

USING PINPOINT TEST

DO NOT run any of the following Pinpoint Tests unless instructed by the QUICK TEST. Each Pinpoint Test assumes that a fault has been detected in the system with direction to enter a specified service routine. Performing Pinpoint Test without direction from the Quick Test may produce incorrect results and cause replacement of undamaged components.

DO NOT replace any parts unless the test result indicates that they should be replaced.

When more than one service code is received, always start service with the first code received.

DO NOT measure voltage or resistance at the ECA or connect any test lights to it, unless otherwise specified.

Isolate both ends of a circuit, and then turn ignition switch to OFF position whenever checking for shorts or continuity, unless otherwise specified.

Disconnect solenoids and switches from the harness before measuring for continuity, resistance or energizing by way of 12 volt source, unless otherwise instructed.

In using the Pinpoint Tests, follow each step in order, starting from the first Step in the appropriate test. Follow each step until the fault is found.

After completing any service to the IVSC system, verify that all components are properly reconnected and repeat Quick Test.

An open is defined as any resistance reading greater than 5 ohms unless otherwise specified.

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

See wiring in Fig. (Scheme 5) as necessary during Pinpoint testing.

ECA Schematic. Scheme 5

DIAGNOSTIC BY SYMPTOM

If control does not work and/or Code 11 is displayed Go to Pinpoint Tests G.

Pinpoint Test A, Schematic. Scheme 6

You should enter this Pinpoint Test only when a Service Code 47, 48, or 49 is received in the KOEO Self Test. To prevent the replacement of good components, be aware that the following non-IVSC areas may be at fault

1. Horn Relay
2. Fuse

The Pinpoint Test is intended to diagnose only the following

1. Speed control switches
2. Brush assembly
3. Slip ring assembly
4. Wiring Harness
5. ECA

1. Service Code 47, did you press the OFF, COAST, ACCEL, and RESUME buttons during the IVSC KOEO Self Test. If no, then repeat IVSC system KOEO Self Test. If yes, then go to step 2 below.
2. Switch does not function, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. Measure resistance between Pin 50 and 39 per table below. Rotate steering wheel through its full range while making resistance checks. RESISTANCE CHECK DVOM Range (Ohms) Button Pressed Resistance Range (Ohms) 200 OFF 0-4 200 COAST 114-126 2000 ACCEL 646-714 5000 RESUME 2090-2310 Are resistances within range? If no, then replace switches. If yes, then replace ECA. Do the resistance values fluctuate within the ranges, or go above the ranges, as steering wheel is rotated? If no, then switches are OK. If yes, then CLEAN brushes and slip rings, relubricate slip rings.
3. Service Code 48, did you press the OFF, COAST, ACCEL and RESUME buttons during the IVSC KOEO Quick Test? If no, then repeat IVSC KOEO QUICK TEST. If yes, go to step 4.
4. Switch is stuck, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. Use Rotunda DVOM 014-00407 or equivalent, on 5000 ohm scale. Measure resistance between Pin 50 and 39. Is resistance reading between 0 ohms and 2310 ohms? If yes, then replace the switches. If no, then replace ECA.
5. Service Code 49, did you press the OFF, COAST, ACCEL and RESUME buttons during the IVSC KOEO Quick Test. If no, then repeat IVSC KOEO QUICK TEST. If yes, go to step 6.
6. Ground circuit to switches open, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. Disconnect speed control switch plug in steering column shroud. DVOM on 200 ohm scale. Measure resistance between Pin 39 and ground terminal in 14290 half of disconnected switch plug. Is resistance reading greater than 5 ohms? If yes, then service open circuit between EEC-IV connector Pin 39 and switch plug ground terminal. If no, then replace ECA.

Pinpoint Test B, Schematic. Scheme 7

You should enter this Pinpoint Test only when a Service Code 74, or 75 is received in the KOEO Self Test. To prevent the replacement of good components, be aware that the following non-IVSC areas may be at fault

1. Brakelamp, brake switch and fuse

The Pinpoint Test is intended to diagnose only the following

1. BOO circuit
2. ECA

1. Service Code 74, did you press the brake during the KOEO Self Test. If no, then repeat KOEO Self Test. Press brake once during test. If yes, then go to step 2 below.
2. BOO circuit cycling, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. Use Rotunda DVOM 014-00407 or equivalent, on 20V scale. Measure voltage between Pin 2 and 40 at the breakout box while depressing and releasing the brake. Does the voltage cycle? If yes, then replace the ECA. If no then go to step 3.
3. BOO circuit short to ground, turn key off.Install Breakout Box and leave ECA disconnected. Disconnect BOO circuit from 14290 harness (12 pin connector). Measure resistance between Pin 2 at the breakout box and ground. Is resistance reading greater than 5 ohms? If yes, service BOO circuit short to ground. If no, service stoplamp circuit.
4. BOO circuit cycling code 75, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. Use Rotunda DVOM 014-00407 or equivalent, on 20V scale. Measure voltage between Pin 2 and 40 at the breakout box while depressing and releasing brake. Does the voltage cycle? If yes, then replace the ECA and repeat Quick Test. If no, then replace go to step 5.
5. BOO circuit short to power, turn key off. Install Breakout Box and leave ECA disconnected. Disconnect BOO circuit from 14290 harness (12 pin connector). Measure voltage between Pin 2 and breakout box and engine block ground. Is voltage reading greater than 10.5 volts? If yes, then service BOO circuit short to power. If no, then BOO circuit is OK; service stoplamp circuit

PINPOINT TEST C - SERVO SOLENOIDS, CODE 81 OR CODES 81 & 82

1. Vent solenoid test, turn key off. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. DVOM on 200 ohm scale. Measure resistance between Pin 13 and 35. If resistance is between 100 and 150 ohms, then service code 81 only, replace the ECA and repeat Quick Test. If resistance is less than 100 ohms, then replace servo and repeat Quick Test. If resistance is greater than 150 ohms, then go to step 3.
2. Check continuity of SOL + CIRCUIT, disconnect harness connector from the servo. DVOM on 200 ohm scale. Measure resistance between Pin 13 and SOL + CIRCUIT at the harness connector. If resistance is less than 5 ohms, then go to step 3. If resistance is greater than 5 ohms, then service open circuit and repeat Quick Test.
3. Check continuity of SCVNT CIRCUIT, disconnect harness connector from the servo. DVOM on 200 ohm scale. Measure resistance between Pin 35 and SCVNT CIRCUIT at the harness connector. If resistance is less than 5 ohms, then go to step 4. If resistance is greater than 5 ohms, then service open circuit and repeat Quick Test.
4. Measure SCVNT SOLENOID RESISTANCE, disconnect harness connector from the servo. DVOM on 200 ohm scale. Measure resistance between SOL + and SCVNT CIRCUIT pins on the servo connector. If resistance is greater than 150 ohms, then replace servo and repeat Quick Test.
5. Vacuum SOLENOID TEST, turn key off. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. DVOM on 200 ohm scale. Measure resistance between Pin 13 and 42. If resistance is between 40 and 75 ohms, then replace ECA and repeat Quick Test. If resistance is less than 40 ohms, then replace servo and repeat Quick Test. If resistance is greater than 75 ohms, then go to step 6.
6. Check continuity of SOL + Circuit, disconnect harness connector from the servo. DVOM on 200 ohm scale. Measure resistance between Pin 13 and SOL + circuit at the harness connector. If resistance is greater than 5 ohms, then service open circuit and repeat Quick Test. If resistance is less than 5 ohms, go to step 7.
7. Check continuity of SCVAC circuit, disconnect harness connector from the servo. DVOM on 200 ohm scale. Measure resistance between Pin 42 and SCVAC circuit at the harness connector. If resistance is greater than 5 ohms, then service open circuit and repeat Quick Test. If resistance is less than 5 ohms, go to step 8.
8. Measure SCVAC solenoid resistance, disconnect harness connector from the servo. DVOM on 200 ohm scale. Measure resistance between Pin SOL + and SCVAC circuit pins at the servo connector. If resistance is greater than 75 ohms, then replace servo and repeat Quick Test.

PINPOINT TEST D - SPEED DOES NOT INCREASE DURING DYNAMIC TEST

You should enter this pinpoint test only when service code 36 is received in the KOER Self-Test. This pinpoint test is intended to diagnose the following

1. Actuator cable
2. Vacuum hose connections
3. Dump valve adjustment
4. ECA
5. Vacuum reservoir
6. Check Valve

1. Service Code 36, repeat KOER Self-Test of QUICK TEST. Be sure that the speed control ON button is pressed before pressing the STAR push button. If code 36 is still present, then go to step 2. If there is no code 36, then increase the vehicle speed, test passed. Service any other service code(s) as necessary.
2. Check actuator cable connection to throttle body, is actuator cable attached to throttle body accelerator linkage. If yes, then go to step 3. If no code, connect servo cable to throttle body accelerator linkage. Repeat Quick Test.
3. Check vacuum hoses. Is servo vacuum supply hose tightly connected to VAC port on manifold check valve and to the vacuum manifold, and free of cuts, cracks and kinks? Are vacuum hoses tightly connected between check valves and servo, and free of cuts, cracks and kinks? Is vacuum hose tightly connected between aspirator check valve and aspirator, and free of cuts cracks and kinks? Is the dump valve hose tightly connected to the servo and to the dump valve, and free of cuts, cracks and kinks? If yes, then go to step 4. If no code, connect servo cable to throttle body accelerator linkage Repeat Quick Test.
4. Check the check valve, disconnect hose between check valves and servo, at the servo end. Apply 60.6 kPa (18 in.Hg) vacuum to open end of hose. Can vacuum be pumped to, and held at 60.6 kPa (18 in.Hg) vacuum? If yes, then go to step 6. If no, then go to step 5.
5. Check the aspirator check valve, disconnect hose between check valves at the manifold check valve end. Apply 60.6 kPa (18 in.Hg) vacuum to open end of hose. Can vacuum be pumped to, and held at 60.6 kPa (18 in.Hg) vacuum? If yes, then replace manifold check valve. Repeat Quick Test.If no, then replace aspirator check valve. Repeat Quick Test.
6. Check dump valve adjustment, is the dump valve adjusted properly so that the valve is closed when the brake pedal is not depressed? If yes, then replace ECA. Repeat Quick Test.If no, then adjust dump valve. Repeat Quick Test.

PINPOINT TEST E - DOES NOT HOLD SPEED DURING DYNAMIC TEST

You should enter this pinpoint test only when service code 27 and/or 28 are received in the KOER Self-Test. This pinpoint test is intended to diagnose the following

1. Speed control servo
2. Vacuum hose connections
3. Vacuum reservoir
4. Check Valve

1. Service Code 27, repeat Engine Running Self-Test of QUICK TEST. Be sure that the speed control ON button is pressed before pressing the STAR push button. If code 27 is still present, then go to step 2. If there is no code 27, then servo leaks down test passed. Service any other service code(s) as necessary.
2. Check vacuum hoses, is vacuum supply hose tightly connected to VAC port on manifold check valve and to the vacuum manifold, and free of cuts, cracks and kinks? Are vacuum hoses tightly connected between check valves and servo, and free of cuts, cracks and kinks? Is vacuum hose tightly connected between check valve and aspirator, and free of cuts cracks and kinks? Is the dump valve hose tightly connected to the servo and to the dump valve, and free of cuts, cracks and kinks? If yes, then go to step 3. If no code, service vacuum hoses. Repeat Quick Test.
3. Check the check valve, disconnect hose between check valves and servo, at the servo end. Apply 60.6 kPa (18 in.Hg) vacuum to open end of hose. Can vacuum be pumped to, and held at 60.6 kPa (18 in.Hg) vacuum? If yes, then replace servo. Repeat Quick Test. If no, then replace check valve, Repeat Quick Test.
4. Check the aspirator check valve, disconnect hose between check valves at the manifold check valve end. Apply 60.6 kPa (18 in.Hg) vacuum to open end of hose. Can vacuum be pumped to, and held at 60.6 kPa (18 in.Hg) vacuum? If yes, then replace manifold check valve. Repeat Quick Test.If no, then replace aspirator check valve. Repeat Quick Test.
5. Service Code 28, repeat engine running Self-Test of QUICK TEST. Be sure that the speed control ON button is pressed before pressing the STAR push button. If code 28 is still present, then replace servo. Repeat Quick Test. If there is no code 27, then servo leaks up and test is passed. Service any other service code(s) as necessary.

PINPOINT TEST F - SPEED DOES NOT DECREASE DURING DYNAMIC TEST

You should enter this pinpoint test only when service code 37 is received in the KOER Self-Test. This pinpoint test is intended to diagnose the following

1. Actuator cable
2. Throttle shaft and linkage
3. Throttle position sensor
4. ECA

1. Service Code 37, repeat KOER Self-Test of QUICK TEST. Be sure that the speed control ON button is pressed before pressing the STAR push button. If code 37 is still present, then go to step 2. If there is no code 37, then decrease the vehicle speed, test passed. Service any other service code(s) as necessary.
2. Check for throttle shaft/linkage binding, is the throttle shaft or throttle linkage binding, maintaining a part throttle opening? If yes, service to eliminate binding. Repeat Quick Test. If no, then go to step 3.
3. Check for speed control linkage binding. Is the actuator cable binding? If yes replace the actuator cable. Repeat Quick Test. If no, then go to step 4.
4. Check for throttle position sensor binding. Is the throttle position sensor binding at a part throttle opening? If yes replace the throttle position sensor. Repeat Quick Test. If no, then replace the ECA. Repeat Quick Test.

Pinpoint Test G, Schematic. Scheme 8

You should enter this Pinpoint Test only when directed from the KOEO Self Test and the Diagnostic by Symptom chart. This pinpoint test is intended to diagnose the following

1. Speed sensor resistance check
2. Short or ground in sensor input circuit
3. Open in sensor input circuit

1. Speed sensor resistance check, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires, etc. Service as necessary. Install Breakout Box and leave ECA disconnected. DVOM on 2000 ohm scale. Measure resistance between Pin 3 and 6. If DVOM reading is less than 180 ohms, then go to step 2. If DVOM reading is greater than 240 ohms, then go to step 3. If DVOM reading is between 180 and 240 ohms, then replace ECA. Repeat Quick Test.
2. Check for short in sensor input circuit, turn key off. Disconnect harness connector from vehicle speed sensor. DVOM on 2000 ohm scale. Measure resistance between the two connector pins on the speed sensor. If DVOM reading is less than 180 ohms, then replace speed sensor. Repeat Quick Test. If DVOM reading is between 180 and 240 ohms, then repair short in wire harness between sensor and EEC-IV pins 3 and 6 or grounded number 150 circuit. Repeat Quick Test.
3. Check for open in sensor input circuit, turn key off. Disconnect harness connector from vehicle speed sensor. DVOM on 2000 ohm scale. Measure resistance between the two connector pins on the speed sensor. If DVOM reading is greater than 240 ohms, then replace speed sensor. Repeat Quick Test. If DVOM reading is between 180 and 240 ohms, then repair open in wire harness between sensor and EEC-IV pins 3 and 6. Repeat Quick Test.

Pinpoint Test Q, Schematic. Scheme 9

You should enter this Pinpoint Test only when directed from the KOER or KOEO Self Test. This pinpoint test is intended to diagnose the following

1. ECA
2. Harness circuits: signal return, STO, STI, Ground

1. Self-Test Input continuity check, turn key off and wait 10 seconds. Disconnect ECA 60 pin connector. Inspect for damaged pins, corrosion, loose wires. Service as necessary. Install Breakout Box and leave ECA disconnected. DVOM on 200 ohm scale. Measure resistance between Self Test input at the Self-Test single pin connector and Pin 48 at the Breakout box. If reading is less than 5 ohms, then go to step 2. If reading is greater than 5 ohms, correct open in circuit.
2. Self-Test Output continuity check, install Breakout Box. DVOM on 200 ohm scale. Measure resistance between Self Test output at the Self-Test connector and Pin 17 at the Breakout box. If reading is greater than 5 ohms, correct open in circuit. If reading is less than 5 ohms, go to step 3.
3. EGO Sensor ground continuity check, install Breakout Box. Turn key off. Measure resistance between EGO ground on engine and Pin 49 at the Breakout box. If reading is less than 5 ohms, then go to step 4. If reading is greater than 5 ohms, check and service EGO sensor ground wire or open circuit bad connection.
4. STO short to ground, install Breakout Box. DVOM on 200,000 ohm scale. Measure resistance between Self Test output at the Self-Test connector and engine block ground. Is resistance greater than 10,000? If yes then replace ECA. Repeat Quick Test. If no, then service shorts to ground. Repeat Quick Test.