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I hope someone can help,I have a 2000 Corvette that went into theft mode several weeks ago,I did the relearn sequence several times,No Start.I clipped the security wires and put in resistor .No Start.I've been tracing wires and grounds for weeks,every fuse that should be powered in On or Start position is powered up.I took out BCM and sent it out for repair,they told me it was fried and couldn't be repaired so I ordered a brand new AC-DELCO unit I put it in,went thru entire relearn procedure twice-No Start.I removed and cleaned ignition switch-No Start.I disconnected clutch safety switch and put in jumper-No Start.If I jump red& purple wires on TDR ,car will start but when jumper is removed it dies.Where do I go from here??
When you jumper the TDR and the ignition switch is On, the car should stay running if nothing else is wrong. I wish I could help you more, all I can suggest is to check your cable connections at the starter solenoid and battery as well as the ground connection. What about your security light is it going off before you try to start the car, if not it still points to problem with the VATS. Keep us posted, I would be interested to know what the solution will be. Good Luck
Your power circuit to the starter is OK since the car start when you jump Red and Purple wire of the TDR relay .
First check with a multimeter if 12 volt pass through the circuit from MaxiFuse 50 to the C2 terminal of TDR relay .
If yes , check if A1 terminal is grounded by the BCM Theft Deterrent Relay control .
If these are OK , your TDR relay shall energize and close contact between C1 and A2 terminals .
If not your TDR relay can be gone or you may have bad continuity in the relay sockets .
All my battery and starter connections are tight and clean,security light goes out after a few seconds.I have no voltage between fuse 50 and C2 terminal of TDR.
All my battery and starter connections are tight and clean,security light goes out after a few seconds.I have no voltage between fuse 50 and C2 terminal of TDR.
You should verify if you have 12 volt between terminal C2 of the TDR and a ground nearby . The G202 shown in the photo inserted in the schematic is close to the passenger footwell where the TDR is located .
If you have 12volt between C2 and G202 when you put the ignition switch in start , then the positive control side of the TDR between fuse 50 and C2 is OK , if you don't have 12v , then it seems like you an open circuit before C2 in this loop and because (maybe minifuse 14 is blown or since you have a automatic transmission , is the Park/neutral switc OK) ?
If you have 12 volt between C2 and G202 in Start posistion and your TDR does not energize , then you can check if the BCM is grounding the A1 terminal of the TDR relay (if not the TDR will not energize ) and last the the TDR relay it self can be bad .
You can remove the TDR form the car and put 12volt on C2 and A1 terminals and mesure with your meter if you get full continuity between C1 and A2 terminals .
I only have 7.5 volts between G202 &C2, how do I check ground between A1and BCM?. TDR relay is good,I have 2 the original and a new one.I also pulled clutch pedal pos.switch and put in jumper,nothing.also headlights do not dim when in start position.mini fuse 14 is good.
If you have only 7.5 volt between C2 & G202 it seems like you have a voltage drop between maxiFuse 50and TDR terminal C2 on 12 (battery voltage)volt minus 7.5 volt = 5.5 volt .
What do you see if you measure between G202 and C2 on MiniFuse 14 ?
I only have 7.5 volts between G202 &C2, how do I check ground between A1and BCM?. TDR relay is good,I have 2 the original and a new one.I also pulled clutch pedal pos.switch and put in jumper,nothing.also headlights do not dim when in start position.mini fuse 14 is good.
Looking at the diagram olearse posted, the 7.5 v you are reading may be ok. note the diagram shows a resistor (internal to the relay) wired parallel to the coil.So if the switch in the BCM is closed, then what you are measuring is the voltage drop across the [coil and] resistor.
What I might ask you to qualify ,is when you say “run”, do you mean starter cranking, or engine running. olearse posted the cranking circuit, not the circuit to provide juice to the coils and injectors. this will help others to help you
All my battery and starter connections are tight and clean,security light goes out after a few seconds.I have no voltage between fuse 50 and C2 terminal of TDR.
i’m guessing you put one lead at fuse 50 and one at c2. A zero volt can mean a couple things.
1. there is 12 v on the circuit and there is an open below
2. there is no voltage
when i’m chasing a problem like this, i like to use a test light. the best one have a bulb and will draw enough current to tell you the circuit has the ability to perform. Then put the clip side of the lead on battery neg. The first test starts at the fuse. if the light lights, then move the ground to the furthest ground point of the circuit, which for this circuit would be the case of the starter, and the BCM lock tab. This simple test will allow you to eliminate ground as an issue.
then start probing at every connection in the circuit. at connectors you need to back-probe. The point where your problem lay will be that probe point that does not light up. When you get to say, normally open relay contacts, that’s where you need to be able to energize the relay, to verify it.
When I say run, I mean engine running.Car starts and runs when I jump red& purple wires on TDR but will not crank with key switch.I've got voltage on fuse 14 when grounded at battery & starter case but not on BCM case.Also I get a reading of 9 volts across outside of BCM case.
I would try reading voltage on both sides of Mini fuse 14, I know you stated that you removed and cleaned the ignition switch, which to me means that you cleaned the contacts, if the contacts which send voltage when you turn the key to start are dirty they will cause a voltage drop. The TDR relay coil should have 12 volts, 7.5 volts is not enough voltage to energize the TDR relay coil.
Measure voltage at clutch safety switch at terminal A and at B, insuring you have 12v there. Unplug TDR and measure at C2, verify 12v there. You can also supply a ground to terminal A1 by using a wire jumper to ground, this will verify that the BCM is or is not providing a ground to the TDR. Hope this helps.
I just found the problem.A9 BCM ground wire not grounding, fixed that, car starts and runs.THANK YOU to everyone who has helped me thru this nightmare.You guys are great
I don't have a photo it was a broken wire,I've already cut,spliced and covered up ,but I can tell what I went thru to find it.K24556 told me to check voltage at mini fuse 14 from G202,starter case, and BCM bracket.I had 12 volts from starter case and G202 but nothing from BCM.I also had a reading of 9 volts across BCM case.I looked up Bcm wiring diagram and pinout to find where BCM grounded.I removed plugs from BCM and took ohm reading on both ground wires.A9 showed OL so I traced the wire to just below factory wrap and found crimped wire,I cut it and spliced it and Bingo.Problem solved , car fired right up.Thank you again to everyone who helped.
Thanks ,Tyrfryr , for detailed feedback on the solution .
The SP208 is a major ground splice point for many of the modules of the car .
Was this splice point 208 located close to the BCM module if you look at the attached photo of the BCM/ TDR relay ?
C5 no start
