DTC B337: Loss Of HVAC Programmer Data: Intermittents
If only Code B337 shows up as "History", without any other codes, then check the ignition feed, CPS ground and data circuits for intermittent faults.
NOTE:
The following numbered steps refer to circled numbers on diagnostic chart. See Fig 1 and Fig 2
. For circuit identification, see Fig 3.
- Checks for intermittent condition.
- Checks to see if the fault is due to a data circuit problem or a power or ground circuit problem.
- Checks to see if the data circuit problem is in circuit No. 800E.
- Checks for power from Ignition Switch output terminal No. 3 to the programmer.
- Checks to see if the power or ground circuit problem is due to the programmer, wiring or the CPS.
- Checks to see if the fault is in circuit No. 800A or at the programmer.
NOTE:
When all diagnosis and repairs are completed, clear codes and verify operation.