Tach Always Indicates Too High Or Too Low
- Enter self-test mode (hold "TRIP RESET" button in and turn ignition switch from "OFF" to "RUN" position). Observe zeroes on digital display and then release "TRIP RESET" button. If display has "F" on it, replace speedometer module.
- If display does not go into self-test mode (no zeroes displayed), "TRIP RESET" button was not held down properly, or button is damaged. Go to SWITCH TEST (MODULE DOES NOT RESPOND TO BUTTONS) test. If display has "P" on it and codes where odometer is displayed, go to next step.
- With cluster in self-test mode, module should be in test No. 1 (note "01" in ones and tenths digits of odometer). Note code where odometer is normally located "xx0S01". Verify that value of "S" is as indicated in table. If values are correct, replace speedometer module. If incorrect, go to next step.
"S" VALUE SPECIFICATIONS
| Engine |
Value of "S" (Option Code) |
| 4-cyl. |
4, 5, 6, 7 |
| V6 |
0, 1, 2, 3 |
- Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION in this article. Check pin "12C" for open or ground. On 4-cylinder engines, check for open. On V6 engines, check for ground. If no problem is indicated, replace speedometer module. If a problem is indicated, repair wiring.