Speedometer Does Not Work, A/T
Speedometer does not Work.Speedmter Circuit <A/T> Part 1:
Speedmeter Circuit <A/T> Part 2:
CIRCUIT OPERATION
- The ignition switch (IG1) circuit is the power source for the speedometer and output shaft speed sensor.
- The output shaft speed sensor is incorporated in the transaxle. The signals from the output shaft speed sensor are referenced for PCM to send a vehicle speed signal to the speedometer. The speedometer calculates the vehicle speed signal to operate the needle of the meter. At the same time, the travel distance is calculated.
TECHNICAL DESCRIPTION (COMMENT)
The cause may be due to malfunction of the output shaft speed sensor circuitry, PCM or speedometer. The output shaft speed sensor is also used by the powertrain control module (PCM), auto-cruise control-ECU.
TROUBLESHOOTING HINTS
- Malfunction of the output shaft speed sensor
- Malfunction of the combination meter (printed-circuit board or speedometer and tachometer)
- Malfunction of the PCM
- Damaged wiring harness or connectors
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A
STEP 1. Check with other meter.
Check to see that the tachometer, fuel gauge and water thermometer are operating normally.
Q: Do all other meters operate?
YES
NO
STEP 2. Using scan tool MB991958, read the MFI system diagnostic trouble code.
CAUTION: To prevent damage to scan tool always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Read the MFI system diagnostic trouble code.
Q: Is DTC P0720 output?
YES: Refer to GROUP 13A, Multiport Fuel Injection (MFI) DIAGNOSIS.
NO: Go to Step 3.
STEP 3. Check combination meter connector C-04 and PCM connector C-111 for damage.
Q: Are combination meter connector C-04 and PCM connector C-111 in good condition?
YES: Go to Step 4.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. The speedometer should work normally.
STEP 4. Check the wiring harness between combination meter connector C-04 (terminal 46) and PCM connector C-111 (terminal 79).
NOTE: Also check joint connector (3) C-02 and intermediate connector C-105. If joint connector (3) C-02 or intermediate connector C-105 are damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Are the wiring harness between combination meter connector C-04 (terminal 46) and PCM connector C-111 (terminal 79) in good condition?
YES: Go to Step 5.
NO: Repair the wiring harness. The speedometer should work normally.
STEP 5. Check in auto-cruise control.
Q: Does auto-cruise control take effect?
YES: Replace the combination meter. The speedometer should work normally.
NO: Replace the PCM. The speedometer should work normally.