"No Communications" with the ECM
My background: Former Chrysler technician, 17 year employee @ Alldata.com as Senior Technical Editor, ASE certified Master Tech (plus numerous other certs)
Vehicle: 1971 Plymouth Barracuda
Engine: 2006 Chrysler 300 6.1 Hemi with original engine harness, ECM, & FCM Transmission: Tremec 6 speed manual
200 PSI compression pressure while cranking.
The ECM has had the SKIM (security) option deleted by All Computer Resources, Inc.
I have triple-checked powers, grounds, 5 volt references, and wiring to both modules. Also has 12 volts & 2 grounds at the OBD connector.
The CAN high & low wires measure 60.8 ohms. Voltages on those lines measures 2.61 volts and 2.43 volts, respectively.
Crankshaft Position Sensor and Camshaft Position Sensor are making their respective outputs, as measured by an external oscilloscope.
The ASD Relay & Fuel Pump Relay do power up when the key is turned on, then the fuel pump relay waits for a cranking signal, then it re-energizes when the engine is cranking.
Has power to the coils & fuel injectors through the ASD relay.
- When I plug in the scan tool, it powers up but can't communicate with the ECM.
- No spark output at the coils
- No fuel injector pulses.
Any ideas for correcting the “No Communications” problem would be greatly appreciated.
According to Chrysler, the Front Control Module (FCM) acts as global communicator for all of the other modules. Does anyone know of a way to bench test the FCM?
Someone else suggested trying another ECM, in case this one is bad. Sure, it could be bad. I'm not sure if it was working before the SKIM delete was performed or maybe it went bad BECAUSE that was performed. I thought about plugging this ECM into another car, just to see if it would communicate, but according to Chrysler, doing that would reactivate the SKIM system, thus negating the $125 SKIM delete that I've already paid for.