Checking the Power Supply and Ground Terminals
Checking the Power Supply and Ground Terminals
Use the diagnostic trouble codes' frozen values as well as the counters, to determine the driving conditions when the problem was detected the first time and how often the problem has occurred. The values show the problem's current status and how intermittent the problem is.
Driving conditions may be, e.g., if the engine was running, what speed the vehicle had/or if it was only Electronic throttle module (ETM) that experienced the low battery voltage.
Example of conclusions one can draw from information based on counters and frozen values:
- The diagnostic trouble code indicates that Electronic throttle module (ETM) has detected that the battery voltage was low, but it is unclear how Engine control module (ECM) has detected the battery voltage. The battery voltage accounted for in the frozen values is the voltage feed to Engine control module (ECM) and not Electronic throttle module (ETM).
If the voltage feed to Engine control module (ECM) is low, this indicates that one should look for a problem that may affect both Engine control module (ECM) and Electronic throttle module (ETM) or may affect other control modules in the vehicle.
- If the battery voltage is OK in the frozen values, this indicates that the problem cause is isolated to the parts of the voltage feed or grounding point that only affects Electronic throttle module (ETM). Check that the connector connections for Electronic throttle module (ETM) are OK and that there is voltage and ground connection for Electronic throttle module (ETM).
- If the counters shows that there has been a single occurrence of the problem before the last 25 driving cycles, or if the problem was generated when the engine speed was 0 rpm and battery voltage to Engine control module (ECM) was 8.9 V, then the vehicle may have stood with the ignition on for a longer time and the battery has been discharged. In this case, check that the battery and its charging status is OK.
- If the battery voltage has been low or high in both Engine control module (ECM) and Electronic throttle module (ETM), when the engine has been running, this may indicate damaged charging regulator or alternator. At too high battery voltage, it may be an external start aid with too high voltage that has been connected to the vehicle.
For markets where the upgraded software, released during 2006 or later, is available, the solution may be to load the upgraded software for the times when the customer has stood with the ignition on and drained the battery or if anyone has connected a starting aid, which have given too high voltage for a short time. Since the upgraded software requires that the engine is running and that the battery voltage is incorrect for more than 30 seconds, then it will prevent the diagnostic trouble code from being generated in these cases.
Remedy as necessary.
Other information:
- See Identifying upgraded software ECM/ETM. Identifying Upgraded Software ECM/ETM
- Checking wiring and terminals
CAUTION: In order for Electronic throttle module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed:
- Ignition off, wait three minutes so that the main relay / system relay releases the voltage feed to, among other, Electronic throttle module (ETM).
- Then turn on the ignition and turn it off again.
- Wait another three minutes, but if the electric cooling fan is running you have to wait another two minutes after the cooling fan has stopped, to ensure that Electronic throttle module (ETM) is shut off correctly.
If this is not done correctly, diagnostic trouble codes may remain even after deletion of diagnostic trouble codes as well as any reconfiguration, despite the problem being fixed.
Continue: Refer to Fault-Tracing Information - Interrupted Fault. Fault-Tracing Information - Interrupted Fault