Code P1633, missing and idling too high

Is the P1633 the only code in the system? It seems unlikely that if the engine light is on and runs poorly that it will only have a keep alive memory code.

This light will turn on due to the code but unless the PCM is damaged causing the light and the running issue, we need a little more to go on.

So let's start with checking fuel pressure while running. Then check for a vacuum leak.

Here are some guides that will help with this. Let me know what you find and we can go from there. Thanks

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Good morning,

Can you list what he has replaced?

https://www.2carpros.com/articles/engine-idles-too-high

https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac

https://www.2carpros.com/articles/engine-backfires-while-running

Is 1633 the only code?

This code is for the keep alive memory for the PCM. Make sure he checks all the fuses for power on both sides. This is not a visual test, it is a power test.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Roy

QB: DTCs P0603 or P1633: Keep Alive Power

QB: Introduction See: Computers and Control Systems > Pinpoint Tests > QB: DTCs P0603 or P1633: Keep Alive Power - Introduction

QB1 CHECK THE 12-VOLT BATTERY TERMINALS

Note:If KAPWR is interrupted to the PCM when a breakout box is installed or the battery is disconnected, DTC P0603/P1605 can be generated on the first power-up.

INSPECT the 12-volt battery cables for loose connections and for corrosion.
Are the 12-volt battery terminal connections in good condition?
Yes

KEY OFF.

GO to QB2
.

No

Repair any concerns found.

QB2 INSPECT THE ENGINE COMPARTMENT FOR PROPER WIRE ROUTING

INSPECT the Electronic Engine Control (EC) system wiring for proper wire routing.

Check the wiring routing to establish if any of the electrical connectors are being stressed due to poorly routed wiring. If necessary re-route the wiring and secure.

Visually inspect wiring and connectors.
Are there any wiring problems?
Yes

Repair as necessary.

No

GO to QB3
.

QB3 CHECK KEEP ALIVE POWER (KAPWR) TO THE PCM

PCM connector disconnected.

Measure the voltage between:

image

While observing the multimeter, grasp the Electronic EC harness and wiggle, shake or bend a small section while working from the battery to the PCM.
Is the voltage less than 10.5 V?
Yes

ISOLATE the fault and REPAIR as necessary.

No

GO to QB4
.

QB4 CHECK FOR A REPEAT OF THE DTC

PCM connector connected.

Clear all DTCs that may have been caused by the PCM disconnect.

Test drive the vehicle and allow the engine to reach normal operating temperature.

CHECK Self-Test DTCs:
Are DTCs P0603 or P1633 present?
Yes

INSTALL a new PCM.

REFER to Section 2, Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM See: Computers and Control Systems > Programming and Relearning > Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM

No

Unable to duplicate or identify the fault at this time.

REFER to Section 4, Diagnostic Trouble Code (DTC) Description for possible causes and additional DTC description information.

GO to Z1 See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Z: Intermittent - Pinpoint Test
.