E029

Code E029 - 4th Gear Switch Circuit Open:

Wiring Diagram for Code EO29 - 4th Gear Switch Open:

CODE E029 - 4TH GEAR SWITCH OPEN

Circuit Description:

The ECM applies 12V to CKT 446 through terminal "C8". When the normally closed 4th gear switch opens (transaxle has applied 4th gear pressure), the voltage on CKT 446 is allowed to increase which is monitored inside the ECM.

The 4th gear switch is located in the transaxle, and allows the ECM to determine if the transaxle has hydraulically applied 4th gear. This information is used by the ECM to calculate TCC application and the EGR duty cycle.

To set a Code E029 the following conditions must be met:

a. TPS greater than 8% (over 800mv).
b. Vehicle speed between 10 and 30 MPH.
c. The 4th gear switch is open (indicates in 4th gear).




Test Description: The following numbered steps correspond with the step numbers on the diagnostic chart.

1. Under normal conditions, the display at this point should be "LO". This indicates that the 4th gear switch is closed (4th gear disengaged).

2. Verifies that CKT 466 from ECM Terminal "C8" is complete and the ECM is supplying battery voltage. If battery voltage is available at the the Transaxle Connector Terminal "B", the fault is an open switch harness inside the transaxle or a faulty 4th gear switch.




Diagnostic Aids:

An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation.

Check For:

a. Poor Connection or Damaged Harness - Inspect ECM harness connectors for backed out terminal "C8", improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.

b. Intermittent Test - If connections and harness checks out ok, monitor EI28 (4th Gear Switch) display while moving related connectors and wiring harness. If the failure is induced, the "4th Gear Switch" display will abruptly change. This will help to isolate the location of the malfunction.