Diagnostics
The EEC IV system has a self-diagnostic function that makes troubleshooting easier. The diagnostic connector located near the battery makes it possible to connect the STAR tester, which displays the diagnostic codes contained in the diagnostic memory of the EEC IV electronic control unit.
To check the contents of the diagnostic memory, connect the STAR tester to the diagnostic socket of the EEC IV system, turn on the tester and read the diagnostic codes. To use the maximum diagnostic capabilities, you should act strictly in accordance with the instructions given in the table describing the diagnostic procedure.
EEC IV System Diagnosis Procedure
Procedure | clarification |
Basic procedure | |
1. Connect the STAR tester to the diagnostic socket. Turn on the tester. Press the test button. | The diagnostic connector is located near the battery. The control code should appear on the indicator. If a low battery message appears, they should be replaced. The code acceptance symbol should be displayed. It indicates that the tester is ready to receive EEC diagnostic signals. |
2. Turn on the ignition. Do not start the engine. | After switching on the ignition, the EEC IV electronic control unit switches to the self-diagnosis mode and after a while is ready for operation. |
3. Read and write down the displayed digital codes of defects. Code "11" or the code of the detected malfunction. | The electronic control unit EEC IV checks the signals from the sensors when the engine is not running and the condition of the data converters. The code "11" means that the system is working. In the event of a malfunction, the corresponding code will be stored in the diagnostic memory of the EEC IV electronic control unit, which will display it during the test of the defective element. |
4. Code "20" is displayed. | This is the division code. It separates the codes displayed during the current control from those recorded in the diagnostic memory during the remaining 40 auto-diagnostic tests. |
5. Read and write down the displayed digital codes. Code "11" or the code of the detected malfunction. | The displayed codes indicate malfunctions detected during the remaining 40 self-diagnostic tests and are stored in memory. Code "11" indicates that no malfunction was detected during the remaining 40 self-diagnostic tests. After code "10" is displayed, the fault codes are displayed only once, and then are erased from the diagnostic memory. |
| The fault code is displayed only once and must be written down immediately (no possibility of repetition) | |
6. Code "10" is displayed. Move the wiring harnesses and their connectors to detect their malfunction. | The EEC IV electronic control unit is in "non-permanent control" mode. |
| The results of previous tests are erased from memory. If the LED blinks, this means that a malfunction has been detected and its code has been written to memory. If necessary, you can repeat the procedure with the engine off to display its code. | |
7. Turn off the ignition. Press the tester button STAR. Turn off the tester, but do not disconnect it from the engine diagnostic connector. | |
8. Eliminate the found faults (see table Trouble-shooting). Continue testing after troubleshooting. | Eliminate the malfunctions corresponding to the indicated codes in points 4, 6 and 7. See the table for the meaning of the codes and troubleshooting methods Trouble-shooting. Once all faults have been corrected, continue the diagnostic procedure. |
Continuous procedure | |
| 1. Connect the STAR tester to the diagnostic socket and turn it on. Press the test button. | After starting the engine and turning on the tester, the self-diagnosis procedure begins in constant (continuous) mode. The tester must show the control code before stabilization. Check to see if the low battery indicator lights up. Replace batteries if necessary. The code acceptance symbol should be displayed. It means that the tester can receive information from the EEC IV electronic control device. |
| 2. After a while, codes of detected faults will be displayed (they should be written down). The display of the code "11" means that no faults were found. Flash all fault codes several times to make sure | The EEC IV electronic control unit starts the sensor test. Their parameters must correspond to those recorded in the permanent memory of the EEC IV device. In case of exceeding the tolerance limits, the EEC IV sends a fault code to the diagnostic tester. Fault codes are displayed by the STAR tester. They should be written down. Code "11" means that no faults were found. |
| 3. Press the tester button. Turn off the tester. Turn off the engine. Do not disconnect | |
| 4. Eliminate the detected malfunctions (see table Trouble-shooting). | The given code numbers correspond to typical faults. Continue after all issues have been resolved |
Engine running procedure | |
1. Turn on the STAR diagnostic tester. Press the test button. | Turn on the tester before starting the engine so that it is ready for operation during engine start. The tester must show the control code before stabilization. Check to see if the low battery indicator lights up. Replace batteries if necessary. |
2. Turn on the ignition and after 3 seconds start the engine. | Wait a short time after switching on the ignition for the EEC IV electronic control unit to start working. The code acceptance symbol should be displayed. It means that the tester can receive information from the EEC IV electronic control device. |
3. The tester should display the code "50". | The code "50" is an identification code and means that the engine is equipped with the European version of the EEC IV electronic control unit. If the code "50" is not displayed, then the type of electronic control device EEC IV should be checked. |
4. Highlighting a series of codes of detected faults. In case of malfunctions, turn off the tester, turn off the engine and eliminate the malfunctions. Then repeat the procedure with the engine running. | If codes are displayed indicating that the engine temperature is too low or the automatic transmission shift lever is not in the neutral position, the electronic control unit does not perform further self-diagnostics. |
5. Increasing the engine speed. | The increase in engine speed is caused by the EEC IV electronic control unit at the start of the dynamic test sequence. The converters and output data of the limit values of the motor operation are checked. The EEC IV electronic control unit tests the controls by simulating various engine operating conditions and then compares the results with data programmed into memory. The detected malfunctions are stored in the diagnostic memory of the EEC IV electronic control unit, and then transferred to the diagnostic tester. |
6. Code "10" is displayed. Immediately after this code is displayed, sharply press the accelerator pedal (engine speed should quickly go beyond 2500 rpm). | After displaying the code "10", you should sharply press the accelerator pedal. With the accelerator pedal depressed, the EEC IV electronic control unit must detect an excess of 2500 rpm. |
7. If the code "44" is displayed, press the STAR button and turn off the engine. Return to step N1 and repeat the entire procedure from the beginning with the engine running. | The code "44" means that the change in the engine speed was not enough. |
| If the code "44" is not displayed, then the procedure should be continued in accordance with paragraph N8. | |
8. Code "11" or codes of detected faults are displayed. Code "11" indicates that no faults were found. Read and write down the displayed fault codes. | The code numbers that are displayed correspond to the faults found during this diagnostic procedure. |
9. Eliminate the malfunctions found in the previous operation. Stop the engine, turn off the STAR tester by pressing its button. If no faults are found (code "11"), you should go to operation N10. | The table of fault codes lists the actions that must be taken to eliminate the detected fault. After troubleshooting, repeat the diagnostic procedure with the engine running. |
10. Code "60" appears. Go to operation N11. | The EEC IV electronic control unit checks the ignition setting. |
| It is not possible to perform manual adjustment of the ignition setting. | |
11. Press the button on the front wall of the STAR tester, turn off the power of the tester, disconnect the tester from the engine diagnostic connector. Stop the engine. | |
Diagnostic codes
Code | Troubleshooting (code) | Troubleshooting Method |
10 | Control code | Move the wire harnesses, press the accelerator pedal |
11 | No Fault Code | |
13 | coolant temperature sensor | see table Trouble-shooting |
14 | Intake air temperature sensor | see table Trouble-shooting |
15 | Throttle position sensor | see table Trouble-shooting |
17 | Absolute pressure sensor | see table Trouble-shooting |
18 | Insufficient battery voltage | Check battery charging circuit |
19 | Memory of the electronic control device EEC IV | see table Checking system elements |
20 | Split Code | It separates the codes displayed during the current control from those recorded in the diagnostic memory during the remaining 40 auto-diagnostic tests |
21 | Wrong ignition signal "PIP" | see table Trouble-shooting |
23 | Coolant temperature sensor - signal voltage too high | see table Trouble-shooting |
24 | Intake air temperature sensor - signal voltage too high | see table Trouble-shooting |
25 | Throttle position sensor - signal voltage too high | see table Trouble-shooting |
27 | Absolute Pressure Sensor - Values Too High | |
31 | Electronic control unit EEC IV | see table Checking system elements |
33 | Coolant Temperature Sensor - Signal Voltage Too Low | |
34 | Intake air temperature sensor - signal voltage too low | see table Trouble-shooting |
35 | Throttle position sensor - signal voltage too low | see table Trouble-shooting |
37 | Absolute pressure sensor values too low | see table Trouble-shooting |
42 | Absolute Pressure Sensor - No response to run test | see table Trouble-shooting |
43 | Throttle Position Sensor - No Response to Operation Test | see table Trouble-shooting |
44 | Accelerator pedal not pressed - too long response time to a sudden change in the position of the accelerator pedal | Repeat test procedure |
45 | RPM sensor damage | see table Checking system elements |
46 | Idle Air Control Valve - Maximum RPM Not Reached | see table Trouble-shooting |
47 | Idle Air Control Valve - Minimum RPM Not Reached | Proceed as for code "46" If the fault persists, check the fuel supply pressure and fuel pressure regulator |
48 | Idle Air Control Valve - Contactor | see table Trouble-shooting |
50 | Identification code of the engine with the European version of the electronic control unit EEC IV | – |
57 | Accelerator pedal depressed during monitoring - too short response time to a sudden change in the position of the accelerator pedal | Repeat the entire test procedure |
60 | Start of operation of the "Service" mode of the STAR tester | This operation provides ignition and idle checks. Since they are fully checked by the EEC IV electronic control unit, no additional check is necessary |
70 | End of the "Service" mode of the STAR tester | |
74 | Incorrect shifting of 3rd and 4th gears in an automatic transmission | |
75 | Incorrect functioning of the clutch of the electromagnetic blocking of the hydraulic transmission of the automatic transmission |
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