Code No. P1637: Memory Backup System
DIAGNOSTIC FUNCTION
JUDGEMENT CRITERIA
PROBABLE CAUSES
- Damaged wiring harness and connectors
- Malfunction of A/T-ECU (Faulty EEPROM)
DIAGNOSTIC PROCEDURE |
STEP 1. Check if diagnosis code P1637 is erased by turning the ignition switch from the OFF position to the ON position. |
Q.
Is the check result normal?
|
 This diagnosis code will be set by disconnecting the battery. If the diagnosis
code is not erased by turning the ignition switch to the ON position, it is judged to be normal. |
|
 Go to Step 2. |
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STEP 2. Check for open circuit in power supply line |
Q.
Is the check result normal?
|
| Go to Step 3. |
|
| Repair the wiring harness. |
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STEP 3. Symptom recheck after erasing diagnosis code |
Q.
Is the check result normal?
|
| Intermittent malfunction |
|
| Replace A/T-ECU. |
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