Test Ch-1A, Charging System No-Code Test
NOTE:
Ensure battery is fully charged and in good condition before proceeding. DO NOT
perform this test unless sent here by another test.
- Inspect generator belt for proper tension and condition. If generator belt is okay, go to next step. If generator belt tension is incorrect or belt is damaged, repair as necessary. Perform TEST VER-3A.
- Start engine. Using scan tool, set engine speed at 2000 RPM for 30 seconds. Using scan tool, return engine speed to idle and read Diagnostic Trouble Codes (DTCs). If any DTCs exist pertaining to charging system, go to appropriate test. See SELF-DIAGNOSTIC DIRECTORY under appropriate TESTS W/CODES . For all other DTCs, see appropriate TESTS W/CODES in SELF-DIAGNOSTICS article in ENGINE PERFORMANCE section. If no DTCs exist, go to next step.
- Turn engine off. Turn ignition on, with engine off. Using scan tool, actuate generator field. Using scan tool in voltmeter mode, backprobe generator field control (Dark Green wire) and Auto Shutdown (ASD) relay output (Dark Green/Orange wire) terminals. See Figure. Voltage should cycle from zero volts to battery voltage every 1 .4 seconds at both terminals.
- While monitoring scan tool voltage display, wiggle wiring from generator field control and ASD relay output terminals to Powertrain Control Module (PCM) and ASD relay. PCM is located in engine compartment, on driver's side front fender, near radiator. ASD relay is in Power Distribution Center (PDC), located in engine compartment. Refer to PDC cover for proper relay location.
- If no interruption of normal voltage cycle exists when wiggling wiring, go to next step. If interruption of normal voltage cycle exists when wiggling wiring, repair wiring where voltage interrupted voltage cycle. Perform TEST VER-3A .
- Using scan tool, read DTCs. If any DTCs exist pertaining to charging system, go to appropriate test. See SELF-DIAGNOSTIC DIRECTORY under appropriate TESTS W/CODES . For all other DTCs, see appropriate TESTS W/CODES in SELF-DIAGNOSTICS article in ENGINE PERFORMANCE section. If no DTCs exist, go to next step.
- Using an external voltmeter, connect voltmeter positive lead to generator BAT (B+) output terminal. See Figure. Connect voltmeter negative lead to positive battery terminal.
- Start engine. Note voltmeter reading. If voltage is 0.4 volt or less, go to next step. If voltage is more than 0.4 volt, repair BAT (B+) circuit between battery and generator for high resistance. Perform TEST VER-3A .
- Ensure ignition is off. Using an external voltmeter, connect voltmeter positive lead to generator case. Connect voltmeter negative lead to negative battery terminal.
- Start engine. Note voltmeter reading. If voltage is 0.1 volt or less, go to next step. If voltage is more than 0.1 volt, repair generator ground circuit for high resistance. Perform TEST VER-3A.
- Disconnect external voltmeter. Using scan tool in voltmeter mode, read and record battery voltage. Using an external voltmeter, measure and record battery voltage between positive and negative battery terminals.
- Compare both voltage readings obtained in step 11). If difference between both voltage readings is less than one volt, test is complete. Perform TEST VER-3A. If difference between both voltage readings is one volt or more, go to next step.
- Ensure ignition is off. Disconnect PCM Black connector. Using scan tool in voltmeter mode, check voltage on PCM Black connector terminal No. 22 (Red wire on XJ body; Red/Yellow wire on ZJ body). See Fig 1. Compare voltage reading to voltage reading obtained using scan tool in step 11).
- If voltage reading is not within one volt of voltage reading obtained using scan tool in step 11), replace PCM. Perform TEST VER-3A . If voltage reading is within one volt of voltage reading obtained using scan tool in step 11), repair high resistance on Red or Red/Yellow wire between PCM Black connector terminal No. 22 and battery. Perform TEST VER-3A .