BCM not seeing the ECM - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

deedilus · 06-08-2011, 10:00 AM

So this is the issue:

BCM is getting a trickle of power, ECM is not getting ANY power (Even though the ECM power wire has power up at the Intelligent Power Distribution module...)
Gauges/AC are getting power and are working, but everything controlled by the BCM (ie., dome light, horn, wipers, indicators, etc.) are NOT working and my headlights turn on immediately when the key is turned to accessory (it's a base, it doesn't have daytimes). Brake lights are also constantly on.
Hazards go on for a split second then cuts off.

We've checked:

All of the fuses and the relay, they're all good.
Took out the ECU and checked all of the plugs on the harness, it's getting NO power what-so-ever, but up at the IPDM it's got power...
Took the BCM out and checked all of it's plugs, it's not really getting anything either. However we hooked up UpRev Cypher and it only connected to the BCM but we could only control the security light and nothing else.
Tried running a ground straight to the ECU, didn't do anything.
Some other things but my brain is fried and I can't remember at the moment....

At first we were thinking (and it's still in the back of our minds somewhat..), is that it's something to do with the motor and harness I bought. My car is an 05 built in 06/05, but the motor we were able to find was an 04. The engine harness (not the engine compartment harness, the engine harness) is from an 04, ECM is from an 05.... But after scouring through the FSM for 04 and 05 that's not an issue... but the IPDM layout is completely different between years, so that is what is bugging us and making us scratch our heads.

Now, we're thinking that the crackhead in Austin that was doing my V8 swap that ruined my car did something behind the dash or fried something.. But when we look back there we don't really see anything wrong with the wiring. We're wondering if maybe the BCM is bad? But that wouldn't really interfere with the ECM getting power I... It's a straight wire directly to it from the IPDM, which has power.

We're thinking about running a wire directly from the battery to the ECM and seeing what that does, but I'm open to all suggestions. Appreciate any help you guys may have!

06-08-2011, 10:00 AM	#1
deedilus Leaky Injector Join Date: Nov 2010 Location: Richmond, VA Posts: 103 Trader Rating: (5) Feedback Score: 5 reviews	BCM not seeing the ECM So this is the issue: BCM is getting a trickle of power, ECM is not getting ANY power (Even though the ECM power wire has power up at the Intelligent Power Distribution module...) Gauges/AC are getting power and are working, but everything controlled by the BCM (ie., dome light, horn, wipers, indicators, etc.) are NOT working and my headlights turn on immediately when the key is turned to accessory (it's a base, it doesn't have daytimes). Brake lights are also constantly on. Hazards go on for a split second then cuts off. We've checked: All of the fuses and the relay, they're all good. Took out the ECU and checked all of the plugs on the harness, it's getting NO power what-so-ever, but up at the IPDM it's got power... Took the BCM out and checked all of it's plugs, it's not really getting anything either. However we hooked up UpRev Cypher and it only connected to the BCM but we could only control the security light and nothing else. Tried running a ground straight to the ECU, didn't do anything. Some other things but my brain is fried and I can't remember at the moment.... At first we were thinking (and it's still in the back of our minds somewhat..), is that it's something to do with the motor and harness I bought. My car is an 05 built in 06/05, but the motor we were able to find was an 04. The engine harness (not the engine compartment harness, the engine harness) is from an 04, ECM is from an 05.... But after scouring through the FSM for 04 and 05 that's not an issue... but the IPDM layout is completely different between years, so that is what is bugging us and making us scratch our heads. Now, we're thinking that the crackhead in Austin that was doing my V8 swap that ruined my car did something behind the dash or fried something.. But when we look back there we don't really see anything wrong with the wiring. We're wondering if maybe the BCM is bad? But that wouldn't really interfere with the ECM getting power I... It's a straight wire directly to it from the IPDM, which has power. We're thinking about running a wire directly from the battery to the ECM and seeing what that does, but I'm open to all suggestions. Appreciate any help you guys may have! __________________ i like chicken nuggets