Codes 21 Thru 27

Code 21

Indicates a problem in the oxygen feedback circuit. On 1984 models, this code appears if there has been no oxygen sensor signal for more than 5 seconds.


Code 22

Indicates a fault in the coolant temperature sensor circuit. This code will appear if the circuit indicates an incorrect temperature or a temperature that changes unusually fast.


Code 23

Indicates a fault in the charge temperature sensor circuit. This code will appear if the circuit indicates an incorrect temperature or a temperature that changes unusually fast.


Code 24


Indicates a fault in the throttle position sensor circuit. This code will appear if the sensor signal is too low (below .16 volts) or too high (above 4.7 volts).


Code 25

Indicates a fault in the AIS control circuit. This code will appear if proper voltage from the AIS system is not present. Note than an open harness or wire will not activate this code.



Code 26

Indicates that peak injector current has not been reached.


Code 27

Indicates internal problem in logic module fuel circuit.