B127

Code B127:

PRND321 & P/N Switch:

DESCRIPTION
The PRND321 sensor, part of the gear selector switch, is mounted on the transaxle and operates as a potentiometer that sends gear selection information to the Body Control Module (BCM) as a variable voltage signal. The PRND321 signal, CKT 356, is calculated as a percent of available ignition voltage to gear selector position. Code B127 will set if the voltage signal is above or below the normal operating range, which could be the result of:
- CKT 139, 356, 24, 434 or 736 open or shorted to ground.
- Faulty gear selector switch or switch adjustment.
- Faulty BCM.
- Faulty terminal contacts of the gear selector switch, dash to engine harness interconnect or BCM.

TEST DESCRIPTION
The numbers below refer to circled numbers on the diagnostic chart:
1. Check BD4i to determine if PRND32i is within normal range of values, with vehicle in park.
2. Incorrect BD4 1 values as the gear selector is cycled through the gears could be a circuit, adjustment, or switch problem.
3. Incorrect B124 values could be a misadjusted switch as well as an open or short to ground in CKT 24. Try adjusting switch before replacing.

NOTES ON INTERMITTENTS
If Code B127 is setting intermittently, review the following:
- Assure the gear selector switch harness is not intermittently shorting to the engine and cowl area.
- Assure good connections in circuits 139, 24, 356, 736, and 434. An intermittent open in any of these circuits could result in an intermittent code.

This code can also be owner induced by selecting a position between two gear positions, or by loading the gear selector against the detent.