Here are the description and diagnostic procedures for the trouble codes. Yes, a faulty computer can trigger the codes.
PCM ( Power control Module) and ECM ( Engine Control Module) are both the same thing, only difference is that PCM includes the transmission control module whereas ECM is mainly refered for manual transmission.
DTC P0561: SYSTEM VOLTAGE UNSTABLE, DTC P0562: SYSTEM VOLTAGE LOW OR DTC P0563: SYSTEM VOLTAGE HIGH
DTC P0561 will set if system voltage is less than 2.5 volts. DTC P0562 will set if 4 minutes or more after engine starts, system voltage is 2.5-10 volts. DTC P0563 will set if 4 minutes or more after engine starts, vehicle speed is more than zero MPH and system voltage is more than 16 volts. Monitor runs continuously. Setting this DTC will not illuminate Malfunction Indicator Light (MIL).
" Generator malfunction.
" Faulty battery.
" Open, high resistance, short to ground or intermittently poor contact between ignition switch, EGI main relay or battery backup circuit and Engine Control Module (ECM).
Vehicle will not run if there is open at ECM in ignition, EGI main relay or battery backup circuit. If any fuses are blown, locate and repair short in appropriate circuit, then replace fuse before starting procedure.
1. Check battery condition and generator output. If problem does not exist, go to next step. If problem exists, repair as necessary.
2. Turn ignition on. Backprobe and measure voltage between ECM connector terminal No. 26 (Green wire) and ground. See Fig. 5 . Also, backprobe and measure voltage between ECM connector terminal No. 54 (Black/White wire) and ground. And backprobe and measure voltage between ECM connector terminal No. 58 (White/Red wire) and ground. If battery voltage exists at each terminal, go to next step. If battery voltage does not exist at a terminal, repair open in appropriate wire.
3. Drive vehicle while monitoring voltage at ECM connector terminals No. 26, 54 and 58. If voltage stays stable at battery voltage at each terminal, check connectors for loose, damaged or corroded terminals. If problem exists, repair appropriate connector. If voltage is unstable at a terminal, locate intermittent poor contact and repair as necessary. If voltage is unstable at ECM connector terminal No. 54, also check EGI main relay control circuit connections and wiring for intermittent poor contact. Repair as necessary.
DTC P1115: ECT SIGNAL FROM ECM TO TCM
1. Ignition ON, engine OFF. Measure voltage between TCM connector No. C229 terminal No. 33 (White/Green wire) and ground. DO NOT disconnect connector. Voltage should be about .61 volt. If voltage is as specified, go to next step. If voltage is not as specified, go to step 3 .
2. Turn engine ON. Measure voltage as specified in step
1 . voltage should be about .73 volts. If voltage is as specified, replace TCM then go to step 4 . If voltage is not as specified, go to next step.
3. Turn ignition OFF. Check White/Green wire between ECM and TCM for any faults. Repair as necessary then go to next step. If wiring fault is not found, replace ECM then go to next step.
4. Erase DTC. Start engine and confirm that DTC does not reappear.
DTC P1624: MALFUNCTION INDICATOR LIGHT (MIL) REQUEST SIGNAL FROM TRANSMISSION CONTROL MODULE (TCM) TO ENGINE CONTROL MODULE (ECM)
This is only a request from TCM to ECM to turn MIL on after a fault is detected by TCM. The fault code is stored in TCM. Freeze frame data is stored in ECM under P1624 request code. Retrieve freeze frame data before clearing DTC P1624 from ECM.
No procedure available from manufacturer.
Monday, November 1st, 2010 AT 9:59 AM