FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

129-171

NOTE
KOEO refers to Key On Engine Off (KOEO)
KOER refers to Key On Engine Running (KOER)
DTC refers to Diagnostic Trouble Code (DTC)
DTCs should be diagnosed in the order they are received.



DTC 129
Insufficient manifold absolute pressure sensor or mass airflow sensor change during dynamic response test KOER.

KOER Hard Code Go to DC13
DC13 - Air Leak at MAF Sensor

DTC 136
Lack of heated oxygen sensor switch during KOER self-test, indicates lean (Bank #2).

KOER Hard Code Go to H1
H1 - Check For Diluted Engine Oil

DTC 137
Lack of heated oxygen sensor switch during KOER self-test, indicates rich (Bank #2).

KOER Hard Code Go to H1
H1 - Check For Diluted Engine Oil

DTC 139
No heated oxygen sensor switches detected (bank #2).

KOEO Memory Code Go to H1
H1 - Check For Diluted Engine Oil

DTC 141
Fuel system indicates lean.

KOER Hard Code Go to HB1
HB1 - Check For Fuel Diluted Engine Oil

DTC 144
No heated oxygen sensor switches detected (bank #1).

KOEO Memory Code Go to H1
H1 - Check For Diluted Engine Oil

DTC 157
Mass air flow sensor circuit below minimum voltage.

KOEO Memory Code Go to DC10
DC10 - Check For Intermittent Sensor

DTC 158
Mass air flow sensor circuit above maximum voltage.

KOEO Hard Code Go to DC21
DC21 - Rerun Self-Test W/MAF Sensor Disconnected

KOEO Memory Code Go to DC21
DC21 - Rerun Self-Test W/MAF Sensor Disconnected

DTC 159
Mass air flow sensor signal higher or lower than expected.

KOEO Hard Code Go to DC1
DC - Mass Air Flow (MAF) Sensor

KOER Hard Code Go to DC1
DC - Mass Air Flow (MAF) Sensor

DTC 167
Insufficient throttle position change during dynamic response test KOER.

KOER Hard Code Go to DH20
DC20 - Check MAF Circuit Output

DTC 171
Fuel system at adaptive limits, heated oxygen sensor unable to switch (Bank #1)

KOEO Memory Code Go to H1
H1 - Check For Diluted Engine Oil