Introduction

Fig. 51 ECCS control unit location.:

The self-diagnostic system identifies malfunctions of signal systems such as sensors, actuators and wire harnesses based on the input signal received by the E.C.C.S control unit, Fig. 51. Various malfunctions are coded and displayed on the control unit by a series of blinking red and green lights. Results of the self-diagnosis are retained in the control unit's memory and are displayed when the mode selector, located on the side of the control unit, is switched to the On position. When displaying malfunction codes, the code number can be determined by counting the number of light pulses. The red light represents the first digit of the code, while the green light represents the second digit of the code. For example, a Code 32 would be displayed as three flashes of the red light, followed by two flashes of the green light. Malfunction codes can be translated as follows:
a. Code 11 -- Crank angle sensor circuit malfunction.
b. Code 12 -- Air flow meter malfunction.
c. Code 13 -- Water temperature sensor circuit malfunction.
d. Code 21 -- Ignition signal malfunction.
e. Code 22 -- Fuel pump circuit malfunction.
f. Code 23 -- Throttle valve switch circuit malfunction.
g. Code 31 -- Models with A/C, Fast Idle Control Device system malfunction. Models less A/C, all monitored systems satisfactory.
h. Code 32 -- Starter signal malfunction.
i. Code 34 -- Detonation sensor circuit malfunction.
j. Code 44 -- All monitored systems satisfactory.