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Preliminary Instructions (M/T)

Record and clear continuous memory codes. Warm engine to normal operating temperature. Accelerate moderately to 40 MPH. Start in first gear, shifting no higher than second gear. Coast down to idle, and stop. Shut engine off. Perform KOEO SELF-TEST  , and record continuous memory codes. Go to step 1).

1) Continuous Memory Code 29/452  Code 29/452 indicates ECA detected incorrect output from VSS sometime during vehicle operation. Possible causes for this code are:

Perform appropriate drive cycle procedure. See procedures in PRELIMINARY INSTRUCTIONS (A/T) or PRELIMINARY INSTRUCTIONS (M/T). Ensure driveability complaint can be verified. If Code 29/452 is still present or driveability complaint can be verified, go to step 2). If code is not present or complaint cannot be verified, fault cannot be duplicated at this time. Clear codes, and see SYMPTOMS in TESTS W/O CODES article in the ENGINE PERFORMANCE Section.

2) Check VSS Circuit Continuity  Turn ignition off. Disconnect VSS sensor. Remove ECA 60-pin connector. Inspect terminals, and repair if damaged. Install EEC-IV Breakout Box (T83L-50-EEC-IV). Measure resistance between VSS DIF (+) terminal at VSS wiring harness connector and test pin No. 3 at breakout box. Measure resistance between VSS DIF (-) terminal at VSS wiring harness connector and test pin No. 6 at breakout box. If any resistance reading is more than 5 ohms, service open circuit in VSS wiring harness and repeat step 1). If both resistance readings are 5 ohms or less, go to step 3).

3) Check VSS Circuits For Shorts To Power Or Ground  Turn ignition off. Ensure ECA and VSS are disconnected. Set DVOM on 200-k/ohm scale. On 1.9L A/T, locate 4EAT module under dash between steering column and left kick panel. Disconnect both 4EAT transmission module wiring harness connectors. On all models, measure resistance between test pin No. 3 and test pins No. 6, 37 and 40 at breakout box. If all readings are greater than 500 ohms, go to step 5) (1.9L A/T) or step 4) (except 1.9L A/T). If any reading is less than 500 ohms, repair shorts in VSS wiring harness and repeat step 1).

4) Check VSS Resistance  Turn ignition off, and wait 10 seconds. Disconnect VSS wiring harness connector. Measure resistance across VSS terminals. If reading is not 190-250 ohms, replace VSS and repeat step 1). If resistance is 190-250 ohms, replace ECA and repeat step 1).

5) Check For Shorted 4EAT Module  1.9L A/T has a VSS circuit input to 4EAT module. This test checks VSS circuit to ensure it is not shorted inside 4EAT module. Turn ignition off. Connect both 4EAT transmission module wiring harness connectors. Measure resistance between test pin No. 3 and test pins No. 6, 37 and 40. If any resistance is more than 500 ohms, reconnect ECA and go back to step 4). If each resistance is not greater than 500 ohms, check for fault in transmission system.

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