Circuit Test D5 - Turbocharger Boost Control Solenoid Valve

Fig 1: TBC Circuits

NOTE: Enter this test only when a Code 42 is displayed during the QUICK TEST procedure or when directed here from another CIRCUIT TEST. This test is intended to diagnose only the following: TBC solenoid, ECA, and wiring harness circuits (TBC and VPWR).

1. Checking System Integrity  - Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.
2. Checking Voltage At ECA  - Install breakout box, leaving ECA disconnected. Set VOM on 20-volt scale. With KOEO, measure voltage between test pins No. 10 and 44 (ground) at breakout box. If voltage reading is less than 10 volts, go to next step. If not, go to step 6).
3. Checking Voltage From TBC Solenoid  - Disconnect ECA. Leave TBC solenoid connected. Set VOM on 20-volt scale. DO NOT  pierce wiring during test. With KOEO, measure voltage between "BR/Y" wire at TBC solenoid and ground. If voltage is less than 10 volts, go to next step. If voltage is not less than 10 volts, repair "BR/Y" wire between ECA and TBC solenoid.
4. Check Voltage To TBC Solenoid  - Disconnect ECA and set VOM on 20-volt scale. With KOEO, measure voltage between "R/BK" wire at TBC solenoid and ground. If voltage reading is less than 10 volts, go to next step. If voltage is not less than 10 volts, replace TBC solenoid.
5. Checking Voltage From Power Relay No. 2  - Leave power relay connected and set VOM on 20-volt scale. DO NOT  pierce wire during testing. With KOEO, measure voltage between "R/BK" wire at power relay No. 2 and ground. If voltage is less than 10 volts, go to CIRCUIT TEST B12  , step 1).
6. Checking TBC Circuit For Shorts To VPWR  - Install breakout box, leaving ECA disconnected. Disconnect TBC solenoid connector. Set VOM on 20-volt scale. With KOEO, measure voltage between test pins No. 10 and 44 (ground). If voltage reading is above zero volts, repair short to VPWR. If voltage reading is zero volts, replace ECA.