Test Procedure
- TC1 DIAGNOSTIC TROUBLE CODE (DTC) P0A23: VERIFY THAT THE CONCERN IS PRESENT
- Record and clear all continuous memory DTCs.
- Retrieve the PCM continuous memory DTCs.
- Is DTC P0A23 present?
Yes No GO to TC2. GO to TC7. - TC2 CHECK THE TGAC CIRCUIT FOR AN OPEN IN THE HARNESS
- Key in OFF position.
- PCM connector disconnected.
- Transaxle Assembly-B connector disconnected.
- Measure the resistance between:
( + ) PCM Connector, Harness Side ( - ) Transaxle Assembly-B Connector, Harness Side TGAC - Pin T5 TGAC - Pin 9 - Is the resistance less than 5 ohms?
Yes No GO to TC3. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - TC3 CHECK THE TGAC CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
- Key ON, engine OFF.
- Measure the voltage between:
( + ) PCM Connector, Harness Side ( - ) Vehicle Battery TGAC - Pin T5 Negative terminal - Is the voltage less than 1 V?
Yes No GO to TC4. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - TC4 CHECK THE TGAC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
- Key in OFF position.
- Measure the resistance between:
( + ) PCM Connector, Harness Side ( - ) Vehicle Battery TGAC - Pin T5 Negative terminal - Is the resistance greater than 10K ohms?
Yes No GO to TC5. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - TC5 CHECK FOR THE TGAC CIRCUIT SHORTED TO SIGNALS IN THE SAME HARNESS
- Measure the resistance between:
( + ) Transaxle Assembly-B Connector, Harness Side ( - ) Transaxle Assembly-B Connector, Harness Side TGAC - Pin 9 ISDN2 - Pin 7 TGAC - Pin 9 GSDN - Pin 10 TGAC - Pin 9 CTO - Pin 1 TGAC - Pin 9 TMAC - Pin 4 TGAC - Pin 9 MSDN - Pin 5 - Are the resistances greater than 10K ohms?
Yes No GO to TC6. REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test. - Measure the resistance between:
- TC6 TGAC FUNCTIONAL TEST
- PCM connector connected.
- Transaxle Assembly-B connector connected.
- Isolate the TGAC pin from the Transaxle-B connector.
- Connect a 5 amp fused jumper wire between the following:
Point A Transaxle Assembly-B Connector, Harness Side Point B Transaxle Assembly-B Connector, Harness Side TGAC - Pin 9 TMAC - Pin 4 - Key ON, engine running.
- Does the engine start now?
Yes No INSTALL a new transaxle assembly. REFER to the AUTOMATIC TRANSAXLE/TRANSMISSION EXTERNAL CONTROLS - HYBRID . GO to TC8. - TC7 CHECK THE TGAC CIRCUIT FOR AN INTERMITTENT CONCERN
- Key ON, engine OFF.
- Access the PCM and monitor the TGAC PID.
- Carefully wiggle all accessible wiring and connectors associated with the circuit and look for a change in the PID state.
- Is a concern present during the wiggle test?
Yes No REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.refer to PINPOINT TEST Z . - TC8 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
Yes No INSTALL a new PCM.
REFER toFLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.