DTC P1121: Neutral Position Switch Circuit High Input (M/T)

Turn ignition on. Using voltmeter connected to ground, backprobe ECM connector B135 (28-pin connector) terminal No. 26. See Figure. If voltage is more than 10 volts in Neutral position, go to next step. If voltage is 10 volts or less in Neutral position, go to step 4.
Using voltmeter connected to ground, backprobe ECM connector B135 (28-pin connector) terminal No. 26. If voltage is less than one volt in all positions other than Neutral, go to next step. If voltage is one volt or more in all positions other than Neutral, go to step 4.
Check for poor contact in ECM connector B135 (28-pin connector). Repair connector. If connector is okay, replace ECM.
Turn ignition off. Disconnect in-line 2-pin inhibitor switch connector in transaxle harness between transaxle and ECM. Using an ohmmeter, measure resistance between terminals of 2-pin transaxle control module (TCM) connector. If resistance is less than one ohm in all positions other than Neutral, go to next step. If resistance is one ohm or more in all positions other than Neutral, repair open in TCM harness. See appropriate wiring diagram in WIRING DIAGRAMS article. If harness is okay, replace neutral position switch.
Measure resistance between ECM connector B135 (28-pin connector) terminal No. 26 and 2-pin transaxle harness connector terminal No. 1. See Figure and Figure . If resistance is less than one ohm, go to next step. If resistance is one ohm or more, repair open in wiring between ECM and transaxle harness connectors.
Measure resistance between ground and 2-pin transaxle harness connector terminal No. 2. If resistance is less than 5 ohms, check for poor contact at transaxle harness connector. If connection is okay, replace ECM. If resistance is 5 ohms or more, repair open in wiring between ground and transaxle harness connector.