DR-1L Checking For Intermittent Failure

Intermittent failures are usually caused by wiring or connections. The fault codes and the ATM (circuit actuation test mode) or sensor test mode can be used to locate source of the intermittent failure. If during testing, fault codes do not reappear, use proper test mode to check indicated circuit. When in the correct test mode, wiggle all wires and connectors in the circuit.
1. When the area of failure is located, the ATM test will be interrupted. If the following fault codes do not reappear, use the ATM test mode indicated below:
a. If fault code 25 is indicated use ATM test mode 03.
b. If fault code 26 is indicated use ATM test mode 02.
c. If fault code 27 is indicated use ATM test mode 02.
d. If fault code 31 is indicated use ATM test mode 07.
e. If fault code 33 is indicated use ATM test mode 05.
f. If fault code 35 is indicated use ATM test mode 04.
g. If fault code 37 is indicated use ATM test mode 08.
h. If fault code 41 is indicated use ATM test mode 09. Connect voltmeter to terminal F2 of alternator and note pulsations.
i. If fault code 42 is indicated use ATM test mode 06.
j. If fault code 43 is indicated use ATM test mode 01.
2. When the area of failure is located, the display on the read-out tool will change. If the following fault codes do not reappear, use the sensor test mode indicated below:
a. If fault code 14 is indicated use sensor test mode 08. Apply 10 inches of vacuum to MAP sensor when checking.
b. If fault code 16 is indicated use sensor test mode 07.
c. If fault code 21 is indicated use sensor test mode 02. Disconnect oxygen sensor electrical connector and ground before testing.
d. If fault code 22 is indicated use sensor test mode 04.
e. If fault code 23 is indicated use sensor test mode 03.
f. If fault code 24 is indicated use sensor test mode 05.
g. If fault code 44 is indicated use sensor test mode 01.