DTC DETECTING CONDITION: Immediately at fault recognition TROUBLE SYMPTOM: Gear is not changed. (No down-shift) 1. ENGINE TYPE FB WIRING DIAGRAM: CVT control system CVT Control System > WIRING DIAGRAM 
| STEP | CHECK | YES | NO | 1.CHECK HARNESS. CAUTION: Start work after ATF cools down. 1) Turn the ignition switch to OFF. 2) Disconnect the TCM connector. 3) Remove the transmission valve cover. 4) Disconnect the control valve body connector. 5) Measure the resistance between TCM connector and chassis ground. Connector & terminal (T10) No. 30 — Chassis ground: | Is the resistance 1 M- or more- | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0976 SHIFT SOLENOID "B" CONTROL CIRCUIT LOW | Repair the short circuit of harness. | 2.CHECK PRIMARY DOWN SOLENOID. 1) Connect the connector for control valve body. 2) Measure the resistance between TCM connector and transmission body. Connector & terminal (T10) No. 30 — Transmission body: | Is the resistance approx. 10 — 13.5 -- (when cold) | Check for poor contact of connector, and if no fault is found, replace the TCM. Transmission Control Module (TCM) | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0976 SHIFT SOLENOID "B" CONTROL CIRCUIT LOW | 3.CHECK HARNESS INSIDE TRANSMISSION. Check for the harness pinch, damage. | Is there any fault in the harness- | Replace the transmission harness. | Replace the control valve body. Control Valve Body |
2. ENGINE TYPE EZ WIRING DIAGRAM: CVT control system CVT Control System > WIRING DIAGRAM 
| STEP | CHECK | YES | NO | 1.CHECK HARNESS. 1) Turn the ignition switch to OFF. 2) Disconnect the TCM and transmission connectors. 3) Measure the resistance between TCM connector and chassis ground. Connector & terminal (B54) No. 30 — Chassis ground: | Is the resistance 1 M- or more- | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0976 SHIFT SOLENOID "B" CONTROL CIRCUIT LOW | Repair the short circuit of harness. | 2.CHECK PRIMARY DOWN SOLENOID. Measure the resistance between transmission connector and transmission body. Connector & terminal (T4) No. 1 — Transmission body: | Is the resistance approx. 10 — 13.5 -- (when cold) | Check for poor contact of connector, and if no fault is found, replace the TCM. Transmission Control Module (TCM) | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0976 SHIFT SOLENOID "B" CONTROL CIRCUIT LOW | 3.CHECK HARNESS INSIDE TRANSMISSION. CAUTION: Start work after ATF cools down. 1) Remove the transmission oil pan. 2) Check for the harness pinch, damage. | Is there any fault in the harness- | Replace the transmission harness. | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0976 SHIFT SOLENOID "B" CONTROL CIRCUIT LOW | 4.CHECK HARNESS INSIDE TRANSMISSION. 1) Disconnect the control valve body connector. 2) Measure the resistance between transmission connector and transmission body. Connector & terminal (T4) No. 1 — Transmission body: | Is the resistance 1 M- or more- | Replace the control valve body. Control Valve Body | Replace the transmission harness. |
3. OUTLINE OF DIAGNOSIS • Detect the ground short of the shift-down fluid pressure control solenoid drive circuit. • Judge as NG if a ground short circuit is detected more than 10 times in the shift-down fluid pressure control solenoid drive circuit. 4. EXECUTION CONDITION Secondary Parameters | Execution condition | 12 V battery system voltage | ≥ 9 V | Commanded duty of shift down pressure control solenoid | 100% |
5. DIAGNOSTIC METHOD If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgment ValueMalfunction Criteria | Threshold Value | Signal of malfunction from solenoid driver IC | ON | As defined by: | | Measured shift down pressure control solenoid voltage ≤ 0.8 V | | Time Needed for Diagnosis: 0.2 seconds Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs. | 
Dtc p0977 shift solenoid "b" control circuit high
Dtc p0974 shift solenoid "a" control circuit high