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RZNT4R · 01-24-2021, 09:16 AM

Right off the bat, when a transmission shifts into gear really hard, it's usually an indicator that the transmission is in fail safe mode. Is the module you are disconnecting the PCM? I dunno, maybe google the part number that's on it? You replaced the PNP switch... is it adjusted correctly? If it doesn't start in Park, does it start in Neutral? Whatever you're unplugging to let the car start, it's obviously seeing the issue again and returning to fail safe mode every time.

P0700, P0707 and P0851 are for the same issue, 700 is a generic code that trips in the PCM when the transmission requests the check engine light, 707 is the TCM seeing the PNP switch issue, 851 is the PCM seeing the TCM sending it the wrong PNP switch value. Ignore U0100 and U0122, they can be caused by the scan tool, I've created those codes myself and I've seen a toyota tech make them with his techstream and start on a wild goose chase looking for the wrong things. The PCM is also the one requesting all your traction/ESP lights, since it can't ascertain the state of the transmission for certain, all that stuff gets inhibited.

P0707 - Transmission Range Sensor "A" Circuit Low:

These DTCs indicate a problem with the park/neutral position switch assembly and the wire harness in the park/neutral position switch assembly circuit. The park/neutral position switch assembly detects the shift lever position and sends a signal to the TCM. For security, the park/neutral position switch assembly detects the shift lever position so that engine can be started only when the shift lever is in P or N. The park/neutral position switch assembly sends a signal to the TCM according to the shift position (P, R, N, D, or M). The TCM determines that there is a problem with the switch or related parts if it receives more than 1 position signal simultaneously. The TCM will turn on the MIL and store the DTC.

When an open or short circuit occurs, the contact points for all shift positions are set to OFF.

Malfunction status:
-All contacts for shift position P, R, N, and D are off
-Continues for 30 sec.

01-24-2021, 09:16 AM	#11
RZNT4R Professional Mechanic Join Date: Apr 2010 Drives: 2017 86 6MT Oceanic Location: Quebec, Canada Posts: 789 Thanks: 17 Thanked 634 Times in 371 Posts Mentioned: 12 Post(s) Tagged: 0 Thread(s)	Right off the bat, when a transmission shifts into gear really hard, it's usually an indicator that the transmission is in fail safe mode. Is the module you are disconnecting the PCM? I dunno, maybe google the part number that's on it? You replaced the PNP switch... is it adjusted correctly? If it doesn't start in Park, does it start in Neutral? Whatever you're unplugging to let the car start, it's obviously seeing the issue again and returning to fail safe mode every time. P0700, P0707 and P0851 are for the same issue, 700 is a generic code that trips in the PCM when the transmission requests the check engine light, 707 is the TCM seeing the PNP switch issue, 851 is the PCM seeing the TCM sending it the wrong PNP switch value. Ignore U0100 and U0122, they can be caused by the scan tool, I've created those codes myself and I've seen a toyota tech make them with his techstream and start on a wild goose chase looking for the wrong things. The PCM is also the one requesting all your traction/ESP lights, since it can't ascertain the state of the transmission for certain, all that stuff gets inhibited. P0707 - Transmission Range Sensor "A" Circuit Low: These DTCs indicate a problem with the park/neutral position switch assembly and the wire harness in the park/neutral position switch assembly circuit. The park/neutral position switch assembly detects the shift lever position and sends a signal to the TCM. For security, the park/neutral position switch assembly detects the shift lever position so that engine can be started only when the shift lever is in P or N. The park/neutral position switch assembly sends a signal to the TCM according to the shift position (P, R, N, D, or M). The TCM determines that there is a problem with the switch or related parts if it receives more than 1 position signal simultaneously. The TCM will turn on the MIL and store the DTC. When an open or short circuit occurs, the contact points for all shift positions are set to OFF. Malfunction status: -All contacts for shift position P, R, N, and D are off -Continues for 30 sec.