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'86 ECU codes

7K views 0 replies 1 participant last post by  KBOX 
#1 ·
1 = Normal (No codes recorded)
2 = AFM signal (Open in VC, VS, VB, or E2 or short in EC)
3 = Ignition signal (no signal from igniter 4 times in a row)
4 = water temp sensor (fault in coolant temp. sensor circuit)
5 = O2 sensor (open in O2 sensor - lean signal only)
6 = RPM signal (No Ne, G signal within several seconds after start)
7 = TPS (circuit fault in TPS signal)
8 = Intake air temp sensor (fault in intake air temp sensor circuit)
9 = (There is no 9)
10 = Starter signal (no STA signal before engine reaches 800 RPM)
11 = Switch signal (AC switch on, TPS idle switch off, or AT shift in D during check)

(You will get a 10 code if vehicle is push started.)

To check codes: (throttle closed, transmission in neutral, all accessories off, engine at normal operating temperature)
Turn ignition ON - do not start;
Short T - E1 on service connector;
read codes as indicated by check engine light flashing.
Normal code is 1 flash every 5 seconds.
Fault codes will read in ascending order, - code - 2.5 second pause - code - 2.5 second pause - code, etc. until all codes are read. They will repeat as long as T - E1 are shorted.

Note: a medium sized paper clip makes a good shorting tool for the diagnostic connector.
 
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