3.
IS THERE DTC P1639 ?
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 P1639 ?
YES
Go to step 4
NO
Intermittent failure, system is O.K at this time.
Go to step 4
Erase the DTC and wait 3 seconds
Check the DTC
IS THERE DTC P1639 ?
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 ECM.
