CODE 23

WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

CODE 23 XXGNOSTFC COLECTOR (Figure 56)

DIA -- SHI I T SE DES

Main code 23 indicates a fault with a shift selector or the wiring between a shift selector and the ECU.

Main

Code

Subcode

Meaning

Primary shift selector fault -- a "cateye" type

display may occur

Primary shift selector mode function fault.

Mode change not permitted

Secondary shift selector fault -- a "cateye"

type display may occur

Secondary shift selector mode function fault.

Mode change not permitted

Shift selector display line fault

Active Indicator Clearing Procedure:

Power down

Manual

Self-clearing

NOTE:

Before troubleshooting, read Paragraph 56.

Troubleshooting:

1. Clear the active indicator for code 23 XX. If code recurs, continue to Step (2).

2. Check for a poor connection at the shift selector.

NOTE:

Code 23 12 can result when the +5V line (wire 124) which powers the shift selector is shorted to

ground. Wire 124 also powers the TPS, OLS, RMR, retarder temperature sensor, and sump oil

temperature sensor and is present in all three ECU connectors.

3. Disconnect the selector "S" harness connector from the ECU and from the shift selector and check

for opens, shorts, and shorts-to-ground between the shift selector and ECU (refer to Section 4).

4. If no problem is found with the shift selector connection or wiring, replace the shift selector.

5. If the condition persists, replace the ECU. If replacing the ECU corrects the problem, reinstall the

original (bad) ECU to confirm that the problem is in the ECU. If the original ECU now works, in-

spect the ECU connectors for any corrosion or damage which may cause an intermittent condition.

If the original problem recurs, reinstall the replacement ECU.

0021 0062