INSPECTION PROCEDURE B-3: R (reverse) position warning function does not work.

CAUTION

Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.

COMMENTS ON TROUBLE SYMPTOM

The ETACS-ECU operates this function in accordance with the input signals below.

Ignition switch (IG1)

Inhibitor switch ("R" position)

If this function does not work normally, these input signal circuit(s) or the ETACS-ECU may be defective.

POSSIBLE CAUSES

Malfunction of the inhibitor switch

Malfunction of the ETACS-ECU

Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. Pulse check

Check the input signals below, which are related to the R (reverse) position warning function.

System switch	Check conditions
Ignition switch (IG1)	When turned from ACC to ON
Inhibitor switch ("R" position)	When the selector lever is moved from the R position to the other position.

OK: The MUT-II/III sounds or the voltmeter needle fluctuates.

Q: Are the check result normal?

All the signals are received normally.: Go to Step 2

.
The ignition switch (IG1) signal is not received.: Refer to inspection procedure P-2 "The ignition switch (IG1) signal is not received"

.
The inhibitor switch (reverse position) signal is not received.: Refer to inspection procedure P-3 "The inhibitor switch (reverse position) signal is not received"

Step 2. Retest the system.

Check that the R (reverse) position warning function works normally.

Q: Is the check result normal?

YES: The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction

).
NO: Replace the ETACS-ECU.