Remote Start works, manually turning key - nope. Has B2101 error. TIPM or WIN at fault?

jve · Jul 5, 2023

Hello.

I have well published issue where my car won't start when i turn key to START position. Everything works normally up until START - dash lights up and remote start also works flawlessly.

For a year or more it worked intermittently - I could turn the key few times until it started. Success rate was better if I pushed key a bit to right/top edge. Now it won't start with turning key no matter how hard I try.

I'm aware of 1st gen WIN module issues where contacts get bad connection - I dissassembled my WIN module, just to find out I have a 3rd gen module - yes, my Chrysler 2009 T&C 4.0L has had a recall of this unit [1] and got a newer module which has better design (it has optical transistors in there that detect key position and no more physical contacts).

Those optical transistors are working correctly - when inspecting CAN messages, the software reports me correctly when the key is in START position - so up until this moment it is OK.

But I have the following error:
B2101 - IGNITION RUN/START INPUT CIRCUIT LOW

I want to localize whether WIN or TIPM is at fault.

I suspect this is PNK/WHT (IGN RUN-START) wire that goes out of WIN module to the TIPM and TIPM may report this error. I actually measured what Voltage there is, but I'd like to ask what would be the expected voltage on this wire? I measured at the WIN module side, voltage on IGN RUN-START changes when changing key positions. When ON position it jumps from (forgot the value, it was <10V) to 11.5V. When START position, it doesn't change and stays the same - 11.5V. Should it change between ON and START? Should it be more?

I have multiple questions in mind:

Is 11.5V too low?
If 11.5V is enough, maybe harness is bad and I should check at TIPM side if there is still ~11.5V.
What if I find 11.5V at TIPM side - maybe WITHIN TIPM itself there is an issue that it thinks voltage too low?

Another question: How do i find PNK/WHT (IGN RUN-START) wire if I search it at the TIPM? Many connectors there, lots of wiring harness. Any diagrams/pinouts available?

So, maybe someone can shed a light?

Ideally elecronics repair shop could repair either TIPM or WIN, less ideally but also OK if I know what to buy & change.

[1] chrysler.com/universal/webselfservice/pdf/R03.pdf

jve · Jul 5, 2023

Okay, it turned out to be wiring - basically at TIPM side (TIPM is a module below/integrated with your fuse box) - it didn't see that 11,5V. When I fixed the wire, it started working - 11,5V is enough for this signal and solves "B2101 - IGNITION RUN/START INPUT CIRCUIT LOW" issue! Now my car again starts with the key

Some pics

Unplugged this connector from TIPM:

Connector removed from TIPM. At the edge, it says "1". Other connectors had different values.

WIN module - pink/white wire - IGN (RUN-START). My car has 11.5V for ON and START position and something less for ACC position. The signal is being OUTPUT from this place.

The broken wire at TIPM connector. Signal INPUT here into TIPM.

By the way, excellent startup sequence is written down at www.underhoodservice.com/tech-tip-servicing-a-malfunctioning-automotive-ignition-switch/ - for a different car, but seems similar enough for Chrysler - at least some parts I did read about chrysler in other places match pretty good.

This is a step-by-step run down of starting the Avenger with the key:
Note: Some of these steps are virtually simultaneous.
1. Key inserted into ignition lock cylinder and turned to start (then left in run), CAN networks become active.
2. The WCM communicates with the key transponder and confirms valid key code data.
3. Ignition switch provides switched battery voltage to the WCM and the TIPM on the F20 circuit.
4. The WCM monitors ignition switch position by a voltage change on the G20 MUX circuit.
5. The WCM broadcasts ignition switch position
message and “ok to start/theft” over CAN IHS to TIPM and other modules, accessories can operate.
6. The TIPM provides PCM ignition feed at up to three terminals depending on broadcasted ignition switch position.
7. TIPM provides 12 volts on starter request circuit C3.
8. The PCM grounds the control of the automatic shutdown relay (will keep on for about 2 seconds without rpm signal).
9. The PCM monitors transmission position/clutch switch, electronic throttle control and theft status over CAN C bus.
10. If the PCM starter inhibits pass, the PCM grounds circuit C3.
11. The TIPM provides voltage to the starter
solenoid on T750 circuit, starter solenoid engages, starter cranks engine.
12. Engine starts, the PCM detects start to run transfer rpm, removes ground on C3 circuit.
13. TIPM removes starter solenoid voltage on T750 circuit.

Starting the Avenger with the remote-start button:
1. Remote start fob button is pressed twice.
2. WCM receives and validates signal, CAN networks become active.
3. WCM sends remote start request out over CAN IHS, only limited accessories are allowed operation.
4. TIPM provides PCM ignition feed.
5. TIPM provides 12 volts on starter request circuit C3.
6. The PCM grounds the control of the automatic shutdown relay (will keep on for about 2 seconds without rpm signal).
7. CCN (cabin compartment node) reports on door lock, door ajar, hood ajar and fuel level status via CAN IHS.
8. PCM monitors transmission position/clutch switch, electronic throttle control, MIL status and brake switch.
9. If PCM starter inhibits pass, PCM grounds circuit C3.
10. The TIPM provides voltage to the starter solenoid on T750 circuit, starter solenoid engages, starter cranks engine.
11. Engine starts, PCM detects start to run transfer rpm, removes ground on C3 circuit.
12. TIPM removes starter solenoid voltage on T750 circuit.
13. PCM will allow engine operation for 15 minutes, will shut off engine if door, hood or brake switch status changes.
To continue into normal operation without shutting off the vehicle:
14. Operator can enter running vehicle with valid unlock fob command and insert key into ignition and turn to run.
15. Ignition switch provides switched battery voltage to the WCM and the TIPM on the F20 circuit.
16. The WCM monitors ignition switch position by a voltage change on the G20 MUX circuit.
17. The WCM sends ignition switch position message and “ok to start/theft” over CAN IHS to TIPM and other modules, vehicle and accessories can operate normally.

Sienile · Jul 6, 2023

I'd looked up the diagnostic procedures before seeing your second post where you had solved it. Posting for others with similar issues. The guide you should use is the one for the module the code is found in.

jve · Jul 6, 2023

Thank you very much.

I forgot what module I had that error, I think WIN module reported it. As per those instructions, I should have "Replace the Ignition Switch."

Glad I didn't replace things all over, none of which would have helped.

P.S. If I had access to proper diagnostic tool earlyer I wouldn't have needed to waste time on dissasembling the WIN module and replacing optical transistor that senses the "START" position of the key. Glad I didn't ruin it.

Remote Start works, manually turning key - nope. Has B2101 error. TIPM or WIN at fault?

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