DTC P1899: P/N Switch Stuck In Park Or In Gear: Testing
- Turn ignition on. Using scan tool, read DTCs. If GOOD TRIP counter is displayed and equal to zero, go to next step. If GOOD TRIP counter is not displayed and equal to zero, go to step 7 .
- Using scan tool, read park/neutral switch input state. Observe scan tool display while moving gear selector through all gear positions. If scan tool displays P/N and D/R in correct gear positions, go to step 7 . If scan tool does not display P/N and D/R in correct gear positions, go to next step.
- Turn ignition off. Disconnect PCM harness connectors. See Figure . Disconnect TRS 10-pin connector located on left side of transaxle. Measure resistance between ground and TRS T41 sense circuit (Black/White wire) at terminal No. 5 at TRS harness connector. See Fig 1 . If resistance is more than 100 k/ohms, go to next step. If resistance is 100 k/ohms or less, repair short to ground in TRS T41 sense circuit.
- Measure resistance of TRS T41 sense circuit between terminal No. 5 (Black/White wire) at TRS harness connector and terminal No. 76 (Brown/Yellow wire) at PCM C2 harness connector. See Figure and Fig 1 . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in TRS T41 sense circuit.
- Reconnect TRS harness connector. Measure resistance between ground and terminal No. 76 (Brown/Yellow wire) at PCM C2 harness connector while moving gear selector through all gear positions. Resistance should switch from more than 10 ohms when transmission is not in Park or Neutral to less than 10 ohms when transmission is in Park or Neutral. If resistance is as specified, go to next step. If resistance is not as specified, replace TRS.
- If no other possible causes are remaining, replace PCM.
- Conditions that set DTC are not present at this time. Perform the following to help identify intermittent condition:
- With engine running at normal operating temperature, wiggle related wiring harness while monitoring related parameters on scan tool. If voltage changes or DTC sets while wiggling wiring harness, repair connectors or wiring harness where wiggling caused voltage to change or DTC to set.
- Review freeze frame information on scan tool. Duplicate conditions present when DTC was set.
- Refer to any technical service bulletins that may apply.
- Visually inspect related wiring harness. Check for chafed, pierced, pinched or partially broken wires.
- Visually inspect related wiring harness connectors. Check for broken, bent, pushed out or corroded terminals.
If a problem is found, repair as necessary. If no problems are found, test is complete.