LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2006 >> XL-7 Base, 4WD, Automatic >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission >> Diagnostic Information and Procedures >> DTC U0001 (No.76): CAN Communication Problem - TCM >> DTC Troubleshooting
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC Troubleshooting

DTC TROUBLESHOOTING CHART

Step Action YES NO
1  Was "A/T System Check" performed?  Go to Step 2. Go to A/T SYSTEM CHECK .
2  DTC check 
  1. Check DTC of ECM, TCM and BCM.

Is there any DTC(s) (other than DTC U0001 in ECM, DTC U0001 in TCM and DTC in BCM)? 		 Go to applicable DTC diag. flow. Go to Step 3.
3  Circuit check 
  1. Turn OFF ignition switch.
  2. Disconnect connectors from TCM and BCM.
  3. Check for proper connection to TCM and BCM at applicable terminals.
  4. If OK, measure resistance between "E229-1" terminal of TCM connector and "G53-9" terminal of BCM connector, between "E229-2" terminal of ECM connector and "G53-1" terminal of BCM connector.

Is each resistance 1 Ω or less? 		 Go to Step 4. "WHT" wire circuit (between "E229-1" terminal of TCM connector and "G53-9" terminal of BCM connector) or "RED" wire circuit (between "E229-2" terminal of ECM connector and "G53-1" terminal of BCM connector) open or high resistance.
4  Circuit check 
  1. Disconnect connectors from ECM.
  2. Check for proper connection to ECM at applicable terminals.
  3. If OK, measure resistance between "E229-1" terminal of TCM connector and "E61-32" terminal of ECM connector, between "E229-2" terminal of TCM connector and "E61-33" terminal of ECM connector.

Is each resistance 1 Ω or less? 		 Go to Step 5. "WHT" wire or "RED" wire in shorted to power circuit.
5  Circuit check 
  1. Measure resistance between "E61-32" terminal of ECM connector and "G53-9" terminal of BCM connector, between "E61-33" terminal of ECM connector and "G53-1" terminal of BCM connector.

Is each resistance 1 Ω or less? 		 Go to Step 6. "WHT" wire circuit (between "E61-32" terminal of ECM connector and "G53-9" terminal of BCM connector) or "RED" wire circuit (between "E61-33" terminal of ECM connector and "G53-1" terminal of BCM connector) open or high resistance.
6  Circuit check 
  1. Turn ignition switch to ON position.
  2. Measure voltage between "E229-1" terminal of TCM connector and vehicle body ground, between "E229-2" terminal of TCM connector and vehicle body ground.

Is each voltage 0 - 1 V? 		 Go to Step 7. "WHT" circuit or "RED" circuit shorted to power supply line.
7  Circuit check 
  1. Turn ignition switch to OFF position.
  2. Measure resistance between "E229-1" terminal of TCM connector and vehicle body ground, between "E229-1" terminal of TCM connector and vehicle body ground.

As they infinite? 		 Go to Step 8. "WHT" circuit or "RED" circuit shorted to ground.
8  Circuit check 
  1. Measure resistance between "E229-1" and "E229-2" terminals of TCM connector.

Is it infinite? 		 Go to Step 9. "WHT" circuit is shorted to "RED" circuit.
9  Do you have oscilloscope?  Go to Step 10. Substitute a known-good BCM and recheck. If malfunction is detected, substitute a known-good TCM and recheck. If malfunction is detected, substitute a known-good ECM and recheck.
10  Waveform range check 
  1. Connect connectors to ECM, TCM and BCM.
  2. Connect oscilloscope between "E229-1" terminal of TCM connector and ground, between "E229-2" terminal of TCM connector and ground.
  3. Check if each range of two waveforms is as specified in illustration below.
G04722565Courtesy of SUZUKI OF AMERICA CORP.

Is it in good condition? 		 Go to Step 13. Go to Step 11.
11  Waveform range check 
  1. Disconnect connectors from BCM.
  2. Connect oscilloscope between "E229-1" terminal of TCM connector and ground, between "E229-2" terminal of TCM connector and ground.
  3. Check if each range of two waveforms is as specified in illustration below.
G04722566Courtesy of SUZUKI OF AMERICA CORP.

Is it in good condition? 		 Substitute a known-good BCM and recheck. Go to Step 12.
12  Waveform range check 
  1. Disconnect connectors from TCM.
  2. Connect connectors to BCM.
  3. Connect oscilloscope between "E61-32" terminal of ECM connector and ground, between "E61-33" terminal of ECM connector and ground.
  4. Check if each range of two waveforms is as specified in illustration below.
G04722567Courtesy of SUZUKI OF AMERICA CORP.

Is it in good condition? 		 Substitute a known-good TCM and recheck. Substitute a known-good ECM and recheck.
13  Communication check 
  1. Disconnect connector from input shaft speed sensor.
  2. Start engine for 1 minute or more.
  3. Check DTC of ECM referring to DTC CHECK .

Is DTC U0001 indicated? 		 Go to Step 14. Substitute a known-good ECM and recheck.
14  Communication check 
  1. Connect connector to input shaft speed sensor.
  2. Disconnect connector from ECT sensor.
  3. Perform "DTC Confirmation Procedure" referring to DTC P0118: ENGINE COOLANT TEMPERATURE CIRCUIT HIGH .
  4. Check DTC for TCM referring to DTC Check .

Is DTC U0001 indicated? 		 Substitute a known-good BCM and recheck. Substitute a known-good TCM and recheck.
scientia non olet · About LEMON Manuals