1st Gear Recognition Switch is used to control fuel quantity and improving a climb performance when going up a sloping road.
This monitoring is to detect the implausible input from 1 st gear recognition switch or neutral switch and carried out only once in the same driving cycle.
If the auto transaxle generates threshold value, the ECM judged this as a fault and DTC is set.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Circuit continuity check | ● Short in 1st gear recognition switch power circuit ● Faulty 1st gear recognition switch ● Faulty ECM |
Enable Conditions | ● Engine run | |
Threshold Value | ● Short for 1st gear recognition switch circuit | |
Diagnostic Time | ● 1 sec. | |
MIL Fuel Limit Fuel Cut EGR Off | ● No ● No ● No ● No |
Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Go to " Power Circuit Inspection " procedure.
Ignition "OFF" & Engine "OFF".
Disconnect 1st gear recognition switch connector.
Ignition "ON" & Engine "OFF".
Measure voltage between terminal 1 of the 1st gear recognition switch harness connector and chassis ground.
Specification : Approx. B+
Is the measured voltage within specifications ?
▶ Go to "Component Inspection" procedure.
▶ Check for short to battery in the power harness.
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check 1st gear recognition switch.
Ignition "OFF" & Engine "OFF".
Disconnect 1st gear Recognition Switch.
Measure continuity between terminal 1 and 2 of clutch switch connector (Component side).
1st gear recongnition switch ON | 1st gear recognition switch OFF |
Continuity (Below 1Ω) | No continuity (∞ Ω) |
Is the measured resistance within specifications ?
▶ Substitute with a known-good ECM and check for proper operation.
If the problem is corrected, replace ECM and then go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known-good 1st gear recognition switch and check for proper operation.
If the problem is corrected, replace 1st gear recognition switch and then go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode and then clear DTC.
Operate the vehicle within DTC Enable conditions in General information.
Are any DTCs present ?
Go to the applicable troubleshooting procedure.
System is performing to specification at this time.