Retrieving Codes
FAULT CODE DEFINITIONS FOR EEC-IV SYSTEMS (34 - 42)
TEST
CODE
CONDITION
34
R
34
O, R, C
34
O, R, C
34
O, R, C
34
C, O, R
35
R
35
O, R, C
35
O, R, C
35
O, R, C
36
R
36
R
37
R
37
R
38
C
39
C
41
R
41
C
41
C
42
R
42
C
49
FAULT CODE DEFINITION
(Cars ONLY): EGR valve not opening
properly
(Cars ONLY): Insufficient EGR flow or
EVP voltage high (SONIC) or PFE sensor
voltage high or out of specification
(Trucks ONLY): EGR control circuit fault
(ex. V8 models)
(Trucks ONLY): EVAP control system
fault / voltage higher than closed limit (V8
models)
Defective EGR pressure transducer sensor
(Cars ONLY): RPM too low for EGR test
(2.3L MAP)
(Cars ONLY): EVP/PFE voltage high
(Trucks ONLY): No EGE position signal,
RPM low
(Trucks ONLY): EVAP control system fault
(V8 models)
System indicates lean at idle
Insufficient RPM increase during speed
control test
System indicates rich at idle
Insufficient RPM increase during speed
control test
DC motor idle speed control / idle tracking
throttle position sensor open circuit
(Cars ONLY): Automatic overdrive not
operating properly (transmission failure)
HEGO (HO2S) sensor voltage low / system
lean
HEGO (HO2S) sensor signal out of range /
always lean
No HO2S switching detected
HEGO (HO2S) sensor voltage high / system
rich
(Cars ONLY): HEGO (HO2S) sensor signal
out of range / always rich
4
Chapter 4