Koeo/Koer Self-Test [Lf]; Koeo (Key On, Engine Off) Self-Test; Koer (Key On, Engine Running) Self-Test - Mazda 2006 MX-5 Service Highlights

KOEO/KOER SELF-TEST [LF]

• The self-test function consists of the KOEO (Key On Engine Off) self-test, performed when the ignition switch is
turned to the ON position and the engine is stopped; and the KOER (Key On Engine Running) self-test,
performed when idling. If a malfunction is detected when either self-test is executed, a DTC is displayed on the
WDS or equivalent. Using the self-test function, the present malfunction or a successful repair is readily
confirmed. Refer to the self-test function table for the corresponding DTCs.

KOEO (Key ON, Engine Off) Self-test

• The KOEO self-test is a powertrain control system self-diagnosis, performed when the ignition switch is turned
to the ON position and the engine is stopped. A KOEO self-test begins when the connected WDS or equivalent
sends an execute command to the PCM.
• As the KOEO self-test is performed, the PCM performs the inspection for set DTCs and if a malfunction is
detected the DTC is displayed on the WDS or equivalent.

KOER (Key ON, Engine Running) Self-test

• The KOER self-test is a powertrain control system self-diagnosis, performed when the ignition switch is turned
to the ON position and the engine is idling. A KOER self-test begins when the connected WDS or equivalent
sends an execute command to the PCM.
• As the KOER self-test is performed, the PCM performs the inspection for set DTCs and if a malfunction is
detected the DTC is displayed on the WDS or equivalent.
KOEO/KOER self-test table
DTC No.
B1342 PCM malfunction
P0011 CMP timing over-advanced
P0012 CMP timing over-retarded
P0016 CKP-CMP correlation
P0030 Front HO2S heater control circuit problem
P0031 Front HO2S heater circuit low input
P0032 Front HO2S heater circuit high input
P0037 Rear HO2S heater circuit low input
P0038 Rear HO2S heater circuit high input
P0069 Manifold absolute pressure/atmospheric pressure correlation
P0101 MAF sensor circuit range/performance problem
P0102 MAF sensor circuit low input
P0103 MAF sensor circuit high input
P0107 MAP sensor circuit low input
P0108 MAP sensor circuit high input
P0111 IAT sensor circuit range/performance problem
P0112 IAT sensor circuit low input
P0113 IAT sensor circuit high input
P0116 Engine coolant temperature circuit range/performance
P0117 ECT sensor circuit low input
P0118 ECT sensor circuit high input
P0122 TP sensor No.1 circuit low input
P0123 TP sensor No.1 circuit high input
P0125 Excessive time to enter closed loop fuel control
P0126
Coolant thermostat stuck open
P0128
P0130 Front HO2S circuit problem
P0131 Front HO2S circuit low input
P0132 Front HO2S circuit high input
P0133 Front HO2S circuit problem
P0134 Front HO2S no activity detected
P0137 Rear HO2S circuit low input
P0138 Rear HO2S circuit high input
01–02–20
ON-BOARD DIAGNOSTIC
Condition
E5U010200000N04
×: Applicable
—: Not applicable
Test condition
KOEO KOER
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× ×
× ×
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× ×
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× ×
× ×
× ×
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× ×
× ×
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× ×
× ×
× ×
× ×
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× ×
× ×
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×
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× ×
× ×