Self-Diagnostic Codes 4 and 5?

1990 NISSAN 300ZX
170,000 MILES • 3.0L • V6 • 2WD • AUTOMATIC
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TPRZ32
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Has anyone ever dealt with Auto Trans Self-Diagnostic codes 4 and 5? The A/T indicating lamp after procedure to get it in automatic transmission self-diagnostics procedure blinks 16 times total. It says Solenoid A and B. Was weird because car drives great then all of a sudden after walking around the mall, the car was driving funny. It almost seems like after shifting it to drive the car starts in like 3rd gear or something and stays in that gear. Doesn't shift up or down on its own, can manually shift to first if needing to get up driveway but at stops and stuff super sluggish. Any advice?

Nissan 300zx Z32.
Apr 12, 2023 at 12:35 AM
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STEVE W.
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The description sounds a lot like the transmission control module has a problem. The light should only flicker 10 times normally. It should go into diagnostic mode then you watch the light, if each flicker is the same it shows no faults. If say the third flicker is longer it would mean there is a problem with the TPS sensor. I would try shifting into each gear manually, if that works then it's more likely a TCM fault or the harness at the transmission end has a problem. I would start with a consault scan tool and see if it can communicate with the TCM, then run the scan tool tests on it to see what it shows. These are the tests for the solenoids which I expect are okay. I would check those and if they pass, look at getting a different TCM.
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Apr 13, 2023 at 8:44 AM