Test Tb: Transmission Control Switch & Transmission Control Indicator Lamp: Testing
NOTE:
After each service or repair procedure has been completed, reconnect all components. Clear DTCs. Repeat QUICK TEST procedures to ensure all EEC-V systems are working properly and DTCs are no longer present.
Perform this test when instructed during QUICK TEST or if directed here by other test procedures. This test is used to diagnose the following:
- Wiring harness circuits (TCIL and TCS).
- Faulty PCM.
- DTC P1780
This DTC indicates Transmission Control Switch (TCS) was not cycled during KOER self-test. Possible causes are:- Faulty TCS.
- TCS not cycled during self-test.
- Open or short in wiring harness.
- Faulty PCM.
Turn ignition switch to ON position. Using NGS tester, select TCS PID. Cycle TCS, then hold switch depressed. If PID value switched from ON to OFF, then indicated ON when switch was depressed, repeat QUICK TEST to cycle TCS. If PID value is not as specified, go to next step.
- Check TCS Circuit Voltage
Turn ignition switch to OFF position. Disconnect PCM 104-pin harness connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Measure voltage between PCM harness connector terminal No. 29 (Tan/White wire) and negative battery terminal while cycling TCS. If voltage reading does not cycle when TCS is cycled, go to next step. If voltage reading cycles when TCS is cycled, replace PCM. Repeat QUICK TEST under DIAGNOSIS & TESTING. - Check Circuit For Short To Ground
Turn ignition switch to OFF position. Disconnect TCS harness connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Measure resistance between PCM harness connector terminal No. 29 (Tan/White wire) and negative battery terminal. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in TCS circuit. - Check Continuity Of TCS Circuits
Connect ohmmeter positive lead to TCS key power at central junction box, and connect negative lead to power terminal at TCS harness connector. Note resistance reading. Measure resistance between PCM harness connector terminal No. 29 (Tan/White wire) and TCS terminal at TCS harness connector. If both resistance readings are less than 5 ohms, go to next step. If either resistance reading is 5 ohms or more, repair open TCS circuit. - Check Circuit For Short To Power
Measure resistance between PCM harness connector terminals No. 29 (Tan/White wire) and 71 (Red wire). If resistance is more than 10 k/ohms, replace TCS. If resistance is 10 k/ohms or less, repair short to power in TCS circuit. - Check TCIL PID
Turn ignition switch to ON position. Using NGS tester, select TCIL PID. Cycle TCS. If PID value changes from ON to OFF, fault is intermittent. Go to TEST Z: INTERMITTENT . If PID value does not change from ON to OFF, go to next step. - Check For Short To Ground In TCIL Circuit
Ensure PCM 104-pin harness connector is disconnected. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. If TCIL turns off, replace PCM. If TCIL remains on, repair short to ground in TCIL circuit. - Check For DTC P1780
Perform QUICK TEST . If DTC P1780 is not present, go to next step. If DTC P1780 is present, go to step 1. - Check Voltage To TCIL
Turn ignition switch to OFF position. Disconnect PCM 104-pin harness connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Measure voltage between TCIL PCM harness connector terminal No. 79 and negative battery terminal. See Fig 1. If voltage is more than 2 volts, replace PCM. If voltage is 2 volts or less, check indicator bulb and fuse. Repair as necessary. If bulb and fuse are okay, repair open in circuit between PCM harness connector terminal and ignition switch.