M/T

DTC P1100
NEUTRAL POSITION SWITCH CIRCUIT MALFUNCTION (M/T VEHICLES)(N - SW)

DTC Detecting Condition
Two consecutive trips with fault.

Trouble Symptom
Erroneous idling.











1. Check input signal for Engine Control Module (ECM).





a. Turn ignition switch to "ON".
b. Measure voltage between ECM and body.

[CHECK]: Connector & terminal:
(B84) No. 78 - Body/5.0 ± 0.5 Volts (Neutral position)
(B84) No. 78 - Body/0 Volts (Other positions)
[YES]: Go to next [CHECK].
[NO]: Go to step 2.

[CHECK]: Is there poor contact in ECM connector?
[YES]: Repair poor contact in ECM connector.
[NO]: Replace ECM with a new one.

2. Check neutral position switch.





a. Turn ignition switch to "OFF".
b. Disconnect connector from transmission harness.
c. Measure resistance between connector terminals of transmission harness.

[CHECK]: Connector & terminal:
(T2) No. 1 - No. 2/1 M-Ohms or more (Neutral position)
(T2) No. 1 - No. 2/10 Ohms or less (Other positions)
[YES]: Go to step 3.
[NO]: Repair transmission harness or replace neutral position switch.

3. Check harness connector between ECM and neutral position switch.





a. Disconnect connector from ECM.
b. Measure resistance of harness connector between ECM and neutral position switch.
[CHECK]: Connector & terminal:
(B84) No. 78 - (B25) No. 1/10 Ohms or less.
[NO]: Repair open circuit of harness between ECM connector and neutral position switch connector.
[YES]: Go to next step.





c. Measure resistance of harness connector between ECM and body to make sure that circuit does not short.
[CHECK]: Connector & terminal:
(B84) No. 78 - Body/1 M-Ohms or more.
[NO]: Repair short circuit of harness between ECM connector and neutral position switch connector.
[YES]: Go to next step.





d. Measure resistance of harness connector between neutral position switch and body.
[CHECK]: Connector & terminal:
(B25) No. 2 - Body/10 Ohms or less.
[YES]: Go to next [CHECK].
[NO]: Repair open circuit of harness between neutral position switch connector and body.

[CHECK]: Is there poor contact in neutral position switch connector?
[YES]: Repair poor contact in neutral position switch connector.
[NO]: Replace ECM with a new one.