2018 Corolla Limited Comms
I was asked to take a look at a 2018 Toyota Corolla iM. It is a no start. The vehicle came with a spare cluster, BCM and PCM in the trunk. The vehicle will not ID. There is no generic OBD communication with engine or transmission. When scanned, the gateway and immobilizer are the only modules found. All fuses are good. Grounds are secure. 22K miles. Vehicle is in prime condition. In looking at wiring diagram, the CAN lines go directly from DLC to gateway module. Immobilizer is found on separate pin on DLC. The vehicle does have radar cruise which uses the gateway. It has a bladed key.
I was confident in suggesting that with powers and grounds verified that the gateway was toast. A new gateway was purchased and installed without anything changing. There are multiple branches coming from the gateway. I can see a single branch going down with a short or open in downstream CAN line. I am confused that the whole network is down past the gateway. Another thought was that it was a secured gateway. The issue with that is the generic OBDII is not reading. I am using an Autel scan tool on this vehicle. According to SI, any shorts or opens will cause a DTC.
The wires to the secure gateway are tiny. Not easy to back probe. Looking through SI there is not much I can find without diagnostic codes being present. My next step will be to start disconnecting splice packs to see if anything new wakes up. It seems like a long shot but the vehicle is not giving me any bread crumbs to follow. I am hoping that another tech has seen this in the past and would be willing to share some wisdom.
There is no evidence of a direct hit but the dealer who bought it thinks there was a close strike.
Hate to say it, that is tough. I've seen all those parts that are in the trunk replaced plus a throttle body. Do you have good reference voltages to your sensors?
I have not checked that yet. I will check when I can get back on it.
Checked Coils, Injectors and several sensors. Found 12v, 3.7v and GND. However no signal to fire injectors or coils.
3.7 for reference voltage? Sounds like you have some direction at least now.
Throttle body terminal five is supposed to be 5 volts. As well asthe accelerator position sensor, canister psi sensor, map, cams, oil psi sensors are supposed to have a 5 volt references.
Hi Mike, Is there any activity when the key is turned on? IPC, Radio, Windows...? I'm wondering if this is a issue with the scan tool used, or if this is a fault with the vehicle. Who is the PMM - the BCM? What networks are on the vehicle? Besides CAN, low speed, MOST, Expansion, Chassis...? I'm making an assumption serial data is transmitted to the gateway and then displayed on the tool…
Instrument Panel lights up, I have not tested all the accessories but most panels are lit. It may be a tool problem. Generic OBD should work on any North American vehicle though. I will try Techstream when I go back. The DLC is electronically isolated from the sub-networks. I would expect the gateway to be the master. It appears the communication is by CAN and LIN. LIN is not yet a priority. I…
Used Techstream with same result as Autel. No Codes, No communication past Gateway. More checking to do when time is available.
Did you ever get back on this one? It's really interesting, so I left the browser tab open. Merry Christmas bro!