Fault-Tracing Information
Fault-tracing information
Checking components
Check if other control modules have diagnostic trouble codes (DTCs) for control area network (CAN) faults. If so, perform all troubleshooting according to these diagnostic trouble codes first. Otherwise, continue as follows.
ECM-922A is stored if the engine control module (ECM) does not receive steering wheel module (SWM) information on the cruise control buttons via the CAN network. The diagnostic trouble code is also generated if the information received by the engine control module (ECM) does not match that sent by the steering wheel module (SWM).
- Using VIDA vehicle communication, check that the parameters "Cruise control ON/OFF button", "Cruise control resume button", "Cruise control SET- button" and "Cruise control SET+ button" indicate correct values. If the buttons work and the information can be read out in the engine control module (ECM), the fault is intermittent. Otherwise the fault is permanent.
Permanent fault
Check whether the steering wheel module (SWM) has stored any diagnostic trouble codes that indicate a fault in the cruise control buttons. Any diagnostic trouble codes that are stored should be fault traced first.
Intermittent fault
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. This information can facilitate searching for an intermittent fault. If for example the trouble code was stored when battery voltage was low and engine speed was equal to 0 rpm, it could indicate that the fault arose when the vehicle was stationary with the ignition on for a long period, thereby draining the battery, or that the fault arose when the customer was attempting to start the vehicle. At start, battery voltage may be low if the battery has been poorly charged. Check the speed at which the vehicle was travelling when the trouble code was stored as cruise control can only be activated at speeds above 30 km/h (18.6 mph).
For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. If the frozen values indicate that the diagnostic trouble code was generated due to low battery voltage during or just after engine start, new software is the solution. This is because the new software requires vehicle speed to be greater than 25 km/h (15 mph) for the test to be active.
Even if the frozen values indicate that the trouble code was generated under other circumstances, software upgrade may be the solution as detection time has been increased to 0.9 seconds. This makes the upgraded software more tolerant to short, intermittent disruptions.
If upgraded software is not available and the frozen values indicate that the fault occurred when battery voltage was low and engine speed was close to 0 rpm, fault tracing should focus on checking the vehicle's power supply, especially battery charge status.
Hint: Using VIDA vehicle communication, check that the parameters "Cruise control ON/OFF button", "Cruise control resume button", "Cruise control SET- button" and "Cruise control SET+ button" indicate correct values. To aid fault tracing, use Component specifications when measuring and checking relevant components and use Wiring diagram, Signal descriptionand Breakout boxto measure and control signals to and front the control module or its components.
Remedy as necessary.
Other information
- Checking wiring and terminals 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 three minutes. If the electric cooling fan is running, you have to wait another two minutes after the electric cooling fan has stopped, to make sure that Electronic throttle module (ETM) has been shut off correctly.
If this is not done correctly, diagnostic trouble codes may remain even after deleting diagnostic trouble codes and any reconfiguration may remain, despite the problem being fixed.
Continue - Information
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Information
FAULT FOUND - Fault Found
Attempt New Test - Checking components
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