By Eric Seifert
ALLDATA Automotive Technical Editor
Darrel’s wife has a 2002 Mitsubishi Diamante that she uses for shuttling around her real estate clients. Recently, the Diamante’s TCL (Traction Control Lamp) came on. Concerned for his wife’s safety, Darrel brought the car by for an inspection. We retrieved a code 72, but could not come up with a cause for the code. I talked to a friend who works for a Mitsubishi dealer and he turned me on to the solution.
Traction Control Diagnostic Trouble Code 72 or 73, “Vacuum Ventilation Control Solenoid Circuit System” may set, and the TCL light may come on, due to excessive ignition signal interference affecting the voltage in the TCL solenoid valve harness. This may also cause MFI DTC P1101 or P1102 to set in the PCM. To eliminate this condition, install a noise filter in the wiring harness at the distributor connector as described in the repair procedure.
The repair will require one Mitsubishi noise filter P/N MM902517.
2001-2002 Diamante models equipped with TCL.
1. Remove the plastic engine cover.
2. Disconnect the 7-pin connector from the distributor. See Figure 1.
3. Use a sharp blade to open the plastic harness covering behind the main loom to expose the wires.
4. At pin 2, cut the white wire 2” from the connector. See Figure 2.
5. Install a noise filter as shown in Figure 3. Be sure that the wires are properly positioned before soldering, and that a clean, strong joint is formed.
a. Solder the black wire to the connector side of the harness.
b. Solder the white/red wire to the harness lead.
c. Install heat shrink tubing over the soldered areas for insulation.
6. Reinstall the plastic harness covering and tape securely for a watertight seal.
7. Position the noise filter between the vacuum control valve bracket and the bolt as shown in Figure 4.
8. Reconnect the distributor connector.
9. Reinstall the plastic engine cover.
Eric Seifert is an ASE certified Master Technician and Engine Machinist, with 20 years of independent shop and parts store experience.
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