I have a friend that offered to sell his 2010 GX460, but it has a no start Condition I am trying to diagnose. There was some water intrusion that collected in the front kick panels, suspecting from sunroof drains.
Engine turns over but does no start. I have a limited scanner (ICON T7) that I have been able to narrow down issues. 1st issue fixed was immobilizer antenna/amplifier around the push start was bad (replaced and was able to confirm communication).
In my summary, immobilizer looks to be working but ECU not getting signal to authorize fuel/coils. See summary below on what I have found in the codes and data streams with IG on.
Symptoms:Engine cranks but does not startStarter runs continuously until button is pressed againIgnition coil circuit codes shown (P0351, P0352, P0353, P0358)"Startability Malfunction" (P1604) stored in ECMKey Scan Tool Results and NotesImmobilizer and Smart Key AuthorizationNumber of registered keys: 2Master Key status: NoMatchSub Key status: NoMatchUnlock Request Receive: NG (not good, failed)Unmatch Code or Form: NoUnmatched Vehicle ID: NoWireless C Code: RegdWireless Starter Com ID: No RegdID Code Difference / Response: No differenceID-BOX sleep/start conditions: No/NoSteering Lock: Unset (but Start Condition: SET)Steering Unlock: NoMatchImmobilizer/ECM/Certification ECU CommunicationEFI/EV Code Receive: NG (failed)EFI/EV ECU Communication: NG (failed)Engine/System Start Condition: OKEngine/System Start Request: OKFrame Error: OKIgnition Circuit StatusIG2 Status: ONIgnition Available Area: ALLIgnition Switch: ONImmobilizer: Unset (immobilizer not authorizing start)Immobilizer when IG-ON: UnsetKey/Body/Entry PIDsC Code Difference, Encrypt, Rolling, Serial: No/OK/No/OK (authorization codes OK, but not accepted)Motor Driver Open/Short: OKNo Response (likely from lock or key module): NoFuel and Engine Control ReadingsFuel Cut Condition: OFF (normal KOEO)Fuel Pump/Speed Status: OFFBattery ground resistance (measured): 1–12 ohms (too high; should be <0.1 ohms for reliable ECM operation)Security and Steering LockSteering Lock Start Condition: SETSteering Lock Sleep Condition: NoNo errors or mismatches in rolling codes, serial numbersDTCs SeenP0351, P0352, P0353, P0358: Ignition coil primary/secondary circuit codes (multiple coils—points to ECM not firing rather than individual coil failures)P1604: Startability Malfunction (engine fails to start after cranking)InterpretationImmobilizer (and Certification ECU) NOT authorizing start—even though keys appear registered, "Unset" and "NoMatch" statuses persist.EFI/EV code reception and communication with ECM: NG—this is a sign that the critical start handshake is failing.High ground resistance measured at battery to engine/chassis—this can disrupt ECM power and communication.Most rolling/encrypt codes show 'OK'; actual immobilizer/authorization not granted to ECM.Steering lock shows 'SET' but not fully matched.Starter activation, fuel system, and ignition switch circuit status look normal; ECM never commands coil drivers due to failed security/network handshake.Steps Already PerformedVerified battery voltage and connections.Checked and measured battery ground resistance (found to be much too high—should be improved).Used T7 professional scanner to access all smart access/immobilizer/key PIDs and engine live data streams.Cleared codes and cycled ignition/attempted with registered keys.Verified number of key codes and match status.Attempted to confirm immobilizer and ECM CAN/LIN network handshake (authorization remains 'unset').
Engine turns over but does no start. I have a limited scanner (ICON T7) that I have been able to narrow down issues. 1st issue fixed was immobilizer antenna/amplifier around the push start was bad (replaced and was able to confirm communication).
In my summary, immobilizer looks to be working but ECU not getting signal to authorize fuel/coils. See summary below on what I have found in the codes and data streams with IG on.
Symptoms:Engine cranks but does not startStarter runs continuously until button is pressed againIgnition coil circuit codes shown (P0351, P0352, P0353, P0358)"Startability Malfunction" (P1604) stored in ECMKey Scan Tool Results and NotesImmobilizer and Smart Key AuthorizationNumber of registered keys: 2Master Key status: NoMatchSub Key status: NoMatchUnlock Request Receive: NG (not good, failed)Unmatch Code or Form: NoUnmatched Vehicle ID: NoWireless C Code: RegdWireless Starter Com ID: No RegdID Code Difference / Response: No differenceID-BOX sleep/start conditions: No/NoSteering Lock: Unset (but Start Condition: SET)Steering Unlock: NoMatchImmobilizer/ECM/Certification ECU CommunicationEFI/EV Code Receive: NG (failed)EFI/EV ECU Communication: NG (failed)Engine/System Start Condition: OKEngine/System Start Request: OKFrame Error: OKIgnition Circuit StatusIG2 Status: ONIgnition Available Area: ALLIgnition Switch: ONImmobilizer: Unset (immobilizer not authorizing start)Immobilizer when IG-ON: UnsetKey/Body/Entry PIDsC Code Difference, Encrypt, Rolling, Serial: No/OK/No/OK (authorization codes OK, but not accepted)Motor Driver Open/Short: OKNo Response (likely from lock or key module): NoFuel and Engine Control ReadingsFuel Cut Condition: OFF (normal KOEO)Fuel Pump/Speed Status: OFFBattery ground resistance (measured): 1–12 ohms (too high; should be <0.1 ohms for reliable ECM operation)Security and Steering LockSteering Lock Start Condition: SETSteering Lock Sleep Condition: NoNo errors or mismatches in rolling codes, serial numbersDTCs SeenP0351, P0352, P0353, P0358: Ignition coil primary/secondary circuit codes (multiple coils—points to ECM not firing rather than individual coil failures)P1604: Startability Malfunction (engine fails to start after cranking)InterpretationImmobilizer (and Certification ECU) NOT authorizing start—even though keys appear registered, "Unset" and "NoMatch" statuses persist.EFI/EV code reception and communication with ECM: NG—this is a sign that the critical start handshake is failing.High ground resistance measured at battery to engine/chassis—this can disrupt ECM power and communication.Most rolling/encrypt codes show 'OK'; actual immobilizer/authorization not granted to ECM.Steering lock shows 'SET' but not fully matched.Starter activation, fuel system, and ignition switch circuit status look normal; ECM never commands coil drivers due to failed security/network handshake.Steps Already PerformedVerified battery voltage and connections.Checked and measured battery ground resistance (found to be much too high—should be improved).Used T7 professional scanner to access all smart access/immobilizer/key PIDs and engine live data streams.Cleared codes and cycled ignition/attempted with registered keys.Verified number of key codes and match status.Attempted to confirm immobilizer and ECM CAN/LIN network handshake (authorization remains 'unset').