3.
IS THERE DTC P1638 ?
YES
a.
Go to step 4
NO
a.
Intermittent failure, system is O.K at this time.
b.
Go to step 4
Erase the DTC
Wait 3 seconds and check the DTC
IS THERE DTC P1638 ?
YES
Go to step 4
NO
Intermittent failure, system is O.K at this time.
Go to step 4
Erase the DTC
Turn the ignition switch OFF and turn the ignition switch ON,
Wait 3 seconds and check the DTC
IS THERE DTC P1638 ?
YES
Replace a known - good ECM if DTC is memorized.
NO
System is O.K
Internal fault. There is no inspection of service possible for this diagnostic trouble code. Erase the fault memory and perform test drive. If the fault cannot be cancelled, temporarily install a good ECM and If problem is corrected, replace the ECM.
